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Showing 45 results for Subject: Endocrinology

Firouzeh Gholampour, Sareh Mansouri,
Volume 0, Issue 0 (7-2019)
Abstract

Background: Renal ischemia/reperfusion (IR) is considered as one of the most prevalent reasons of acute renal failure (ARF). As renal failure is progressed, renal gluconeogenesis and insulin clearance are decreased. Berberine is the most important alkaloid of Berberis vulgaris. It has anti-diabetic, anti-inflammatory, and anti-microbial properties. The goal of this study was to assign the effect of RIR on the pancreas and to define the effect of berberine on the pancreatic damages induced by RIR. Methods: Male rats were allocated into four groups (n=7): Sham (no intervention), Ber (Berberine, 15 mg/kg/day), I/R (subjected to 45 min bilateral renal artery occlusion), Ber + I/R (Berberine, 15 mg/kg/day). After 24 hr, blood samples were gathered for biochemical analysis, and eventually pancreas tissue samples were kept for subsequent histological examination. Results: The ischemic challenge of kidneys resulted in pancreatic vascular congestion, which was associated with decreased plasma level of glucose as well as increased plasma insulin, creatinine, and blood urea nitrogen levels at the termination of reperfusion period. In Ber + I/R group, pancreatic vascular congestion and decreased plasma level of insulin were improved concomitant to increase in plasma creatinine and urea nitrogen being smaller than those of the non-treated rats. Berberine exhibited an ameliorative effect on the pancreas against RIR-induced damages. Conclusion: RIR injury has some roles in the development of tissue damages and probably functional disorders of the pancreas in rats. Furthermore, berberine has an ameliorative effect against organ injury induced by RIR in rat.
Mohammad Shabani, Saleh Zahedi Asl, Homa Manaheji,
Volume 10, Issue 1 (4-2006)
Abstract

Introduction: Verapamil, a phenylalkylamin –type Ca2+ channel blocker, is widely used in the treatment of cardiovascular disorders especially as an antiaryhthmic and antiangina agent. Theoretically, calcium can influence thyroid function and there are evidences that Ca2+ channel blockers are able to interfere with thyroid function. In this study, the effects of chronic oral administration of verapamil on thyroid function of male Wistar rats were investigated. Methods: Study was performed on 5 groups of animals groups 1 to 3 were treated with verapamil at doses of 10, 20 and 50 mg /kg respectively for two months via oral tube. Sham group received only distilled water, while control group received neither verapamil nor distilled water. At the end of this period animals were anaesthetized, abdomen was opened and blood samples were obtained from abdominal aorta. The samples were centrifuged sera were separated and stored at – 20 ◦C until the time of the assays. Total triiodothyronine (TT3), total thyroxin (TT4), free triiodothyronine (FT3) and free thyroxin (FT4), T3 uptake levels were assayed by ELISA (DRG). Thyroid stimulating hormone (TSH) was determined by radioimmunoassay using DRG kits. Results: Total T4 level was significantly lower in sham (3.49 ± 0.1μg/dl) and verapamil dose 10 mg /kg (3.6±0.14) groups than in control group (4.5±0.34), while it was significantly higher in verapamil 50 mg /kg (4.24±0.2) group as compared to the sham group. Total T3 concentration in verapamil 20 mg /kg group (62±8.9ng/ dl) was decreased significantly compared to the control group (103.3±14). Free T3 and free T4 were significantly lower in sham group (p<0.005) compared to control group, while it was increased in verapamil groups of 20 and 50 mg /kg compared to sham group. Level of T3 up-take was decreased significantly (p<0.005) in sham (20.97±1.49%) and verapamil 20 (20.7±1.4) mg /kg compared to control group (27.6±1), while it was higher in verapamil 10 and 50 mg /kg groups than sham group. Thyroid stimulating hormone levels were similar in all groups. There were no significant differences in the T3/T4 ratio and body weights on first and last day of the groups compared to control group. Conclusion: It can be concluded that long term oral administration of verapamil doesn’t have inhibitory effect on thyroid function, however it can block adverse effect of handling stress on thyroid function. Therefore, from thyroid function point of view, the drug can be used safely for the duration of this study.
Shohreh Iranmanesh, Akbar Vahdati, Taji Afrouz,
Volume 10, Issue 2 (3-2006)
Abstract

Introduction: Estrogen is one of the female sex hormones that in addition to its reproductive role, has favorable fects on the metabolism of blood lipids and lipoproteins and by this way decreases the coronary heart disease. n the other hand, phytoestrogens are phytochemical substances that have effects like estrogens. Isoflavones, hich the most important of them is genistein, are the most common form of phytoestrogens. In this research, the fects of one phytoestrogenic compounds named genistein and one estrogenic compound named ethinyl estradiol ere compaired. The purpose of this comparison was to study of replacement possibility of phytoestrogens in RT period for elimination of side effects of estrogenic compound. Methods: First the rats were fed for 2 months with high cholestrol diet (2% cholestrol, 0/5% cholic acid). fter the first blood test ensured the hypercholestrolemic condition, the rats were treated for 2 months with ethinyl stradiol and genistein besides of high cholestrol diet. After the end of the second period and serum preparation om the blood samples disignated total cholestrol, triglyceride, HDL, LDL and VDL were measured and the sults were statistically analyzed. Results: According to the obtained results of the first period of experiment, the usage of high cholestrol diet aused meaningful increase in total cholestrol and LDL as it made rats hypercholestrolemic. According to the sults of second period of experiment, the usage of ethinyl estradiol reduced the level of serum total cholestrol nd LDL of hypercholestrolemic rats, that was because of the effect of estrogen on increase of LDL catabolism. hereas, it did not produce meaningful changes in triglyceride, HDL and VDL. Usage of genistein in isolated rm had no benefical effect on blood lipids and lipoproteins, Because hypocholestrolemic property of isoflavone epends on matrix that is beside it.
Mozhdeh Mansouri, Homayoun Khazali,
Volume 12, Issue 2 (8-2008)
Abstract

Introduction: Previous studies have shown that ghrelin inhibits the activity of Hypothalamus –Pituitary – Thyroid (H–P-T) axis. It is also proved that ghrelin increases appetite via Agouti Related Protein and neuropeptide Y pathway, decreases T3 & T4 secretion and inhibits serotonin release from hypothalamic synaptosomes. Serotonin may interact with ghrelin in control of thyroid hormones secretion. Thus, the goal of this study was to determine the influence of the interaction between ghrelin and serotonin agonist on thyroid hormones concentration. This is a suugestive mechanism to determine the effect of serotonin agonist in decreasing the effect of ghrelin. Methods: Twenty four male Wistar rats weighing 230-250 g were randomly divided into 3 groups. The groups respectively received 5 nmol ghrelin ,20 nmol serotonin agonist (R)-8-OH-DPAT or 5 nmol ghrelin with 20 nmol (R)-8-OH-DPAT in the volume of 5μl during 3 days via lateral cerebral ventricle. The blood samples were collected from one day before to one day after injections and brain slices were taken to ensure the place of the canulae is right. The plasma were analysed by Radio Immuno Assay technique to determine T3 and T4 concentrations. Results: The results of this experience showed that the (.i.c.v) injection of ghrelin and (R)-8-OH-DPAT respectively decreased and increased the mean plasma concentrations of thyroid hormones significantly (p<0.05), while the interaction of these two substances showed that (R)-8-OH-DPAT can decease the inhibitory effect of ghrelin on thyroid hormones concentration, but this effect is not statistically significant. (p<0.05) Conclusion: This study showed that ghrelin decreased mean plasma concentration of T3 & T4 significantly and serotonin agonist while injected with ghrelin , because of the stronger effect of ghrelin, could not significantly inhibit this effect of ghrelin. (p<0.05)
Asghar Ghasemi, Hamid Farahani, Saleh Zahedi Asl,
Volume 12, Issue 3 (11-2008)
Abstract

Introduction: Repeated hyperglycemia play an important role in the development of atherosclerosis in diabetic patients. Endothelium is the organ of the first-line defense against atherosclerosis and nitric oxide has a major role in this task. The aim of this study was to determine changes in plasma nitric oxide metabolites concentration during glucose tolerance test in type 2 diabetic rats. Methods: Male neonate Wistar rats divided into control and diabetic groups. Type 2 diabetes was induced by administration of Streptozotocin (100 mg/kg) to neonate rats at day 2. Plasma glucose and nitric oxide concentration were measured at 7, 30, 45, 60, and 75 days. Intravenous glucose tolerance test was done in adults rats and blood samples were collected in 0 and 5, 10, 30, and 60 min after glucose infusion for determining plasma glucose, insulin, and nitric oxide metabolites. Two-way mixed (between-within) ANOVA was used for comparing data. Results: In control group plasma glucose was returned to basal values 60 min after glucose injection while in diabetic rats it was higher than basal levels (P<0.001). After glucose injection, plasma insulin concentration was increased to 4.5 and 1.9 folds in control and diabetic groups respectively. Basal nitric oxide metabolites concentration was higher in diabetic rats (50.4 ± 6.4 vs. 28.8 ± 3.8 mol/l, P<0.05). During glucose tolerance test there was 35 and 62 % fall in plasma nitric oxide concentration in control and diabetic groups respectively. This reduction return to basal values after 30 min in control group while, in diabetic rats it was 17% less than basal levels in 60 min after glucose injection. Conclusions: Decreased nitric oxide production or increased its degradation may be underlying endothelium dysfunction and atherosclerosis in type 2 diabetes.
Saleh Zahedi Asl, Hamid Farahani, Asghar Ghasemi, Farzaneh Faraji Shahrivar,
Volume 12, Issue 4 (1-2009)
Abstract

Introduction: Many of the diseases of adulthood are originated from the intrauterine conditions during fetal life. Because of the importance of thyroid hormones in growth and development of the fetus, the effects of maternal hypothyroidism on carbohydrate metabolism in adulthood was investigated. Methods: Pregnant rats were divided into the fetal hypothyroidism (FH) and the control (C) groups. During the gestational period, propylthiouracil (PTU) dissolved in drinking water (100 ppm) was administered to the FH group, while the C group drank tap water. After delivery and maturation of male neonates, intravenous glucose tolerance test (IVGTT) was performed. For IVGTT tests, catheters were inserted into the femoral vein and artery after anesthesia. The first arterial sample was taken before injections, then the glucose solution was injected and other samples were obtained after 5, 10, 15, 20, 30 and 60 minutes. Plasma glucose and insulin concentrations were measured using the glucose oxidase and an ELISA method, respectively. Results: Plasma glucose concentration 5 min after glucose injection in the FH group (239.2 ± 15.6 mg/dL) was significantly higher than the C group (190.1 ± 4.5 mg/dL, P<0.05). There was no significant difference in plasma insulin concentrations of the 2 groups. Daily water consumption during the gestation in PTU administered mothers was significantly lower compared to the C group (P<0.05). The body weight of animals was significantly (P<0.05) lower in the FH group compared with the C group. Conclusion: Maternal hypothyroidism can alter carbohydrate metabolism during adulthood, which may contribute to the development of diabetes.
Behnam Sedghi, Seddigheh Kahrizi, Hmidreza Zakeri, Kobra Omidfar, Mazaher Rahmani,
Volume 13, Issue 2 (8-2009)
Abstract

Evaluation of The Acute Hormonal Responses To Concentric, Eccentric And Concentric_ Eccentric Muscle Actions in Healthy Young Men Introduction: Resistance exercise is a potent stimulus for acute increase in the concentrations of circulating hormones such as Growth Hormone (GH) and Testosterone. Conventional resistance exercise is performed using sequential concentric (CON) and eccentric (ECC) contractions that is performed at a external constant load. The aim of this study, is determining hormonal and metabolic response to CON, ECC and CON-ECC muscle actions in order to develop appropriate resistance exercise protocols and equipment for both athletic populations and patients recovering from injury. In the present study, we have examined the endocrine system responses to six different upper and lower body exercise utilizing the CON, ECC and CON_ECC contractions. Methods: In this study, we examined acute hormonal responses of GH, TT & FT and cortisol of 10 young men who had experienced resistance exercises nonprofessionally. The exercise protocol included six resistance exercise which three of them were upper body and the other three were lower body exercises. The participants performed 3 contraction actions in 3 different days with at least one week interval and at the same time of the day. The exercise protocol included 4 sets in each exercise, every exercise was done 10 repetitions per set, and the resting time between exercises and sets was 90 seconds. CON and ECC actions performed at intensity of 80% CON 10-RM and 80 %( 120% CON 10-RM), respectively. Considering to the counterbalanced force design and on the calculations was done, the intensity of CON-ECC action was 88%CON 10-RM. Blood samples were collected before the exercise, immediately, 15, and 30 minutes after exercise session. Results: In the effect of CON, ECC and CON-ECC contraction actions GH increased, but after CON and CON-ECC trials increased significantly, only. In the effect of three actions, TT & FT increased significantly and following the three actions, cortisol decreased significantly. Conclusion: In despite of existence of significant increase in TT & FT acute response and significant decrease in cortisol response in the effect of CON, ECC and CON-ECC contraction actions, significant difference didn’t observe, that this issue demonstrating that the response of these hormones did not influence by type of contraction action. Also, between acute GH response related to these three actions, observed significant difference that demonstrating GH response depends on type of muscle action and degree of the motor units recruitment besides on intensity and volume of exercise. Key Words: Concentric and Eccentric Contractions, Acute hormone response, Growth Hormone, Total & Free Testosterone, Cortisol.
Fatemeh Masjedi, Ali Gol, Shahriar Dabiri, Abdoreza Javadi,
Volume 13, Issue 2 (8-2009)
Abstract

Introduction: The preventive antidiabetic effects of garlic juice on blood glucose levels and pancreas tissue was evaluated in STZ-induced diabetic rats. Methods: 40 male rats were divided into five groups of 8 rats each. 1) Normal group (N), 2) Normal+Garlic group (N+G) received 1 ml garlic juice/100g BW/day for 6 weeks, 3) Diabetic group (D) injected with streptozotocin (60 mg/kg BW,i.p.), 4) Diabetic + Garlic_before group (D+Gb) received garlic juice for 6 weeks, but at the end of third week, they were injected with STZ, 5) Diabetic+Garlic_after group (D+Ga) received garlic juice for 3 weeks, after they were injected with STZ. At the end of the experiment, serial sections of pancreas were prepared and stained with H&E for light microscope investigations. Results: Serum glucose levels were significantly increased (p<0.05) in D group in comparison with other groups. There was no significant difference between D+Gb group and N and N+G groups. Body, pancreas, and relative weights was significantly decreased (p<0.05) in D group in comparison with other groups. In D+Gb and D+Ga groups pancreas weight showed no significant difference with the normal group. In D group decrease of pancreatic islet numbers and their mean diameter, atrophy and vacuolation in parenchyma of pancreatic islets were detected. These abnormal histological signs were dramatically decreased in D+Gb group compared to D group. In D+Ga group, dramatical but slighter effects of garlic juice on the histopathological changes of the pancreas were observed. Conclusion: Based on these results, it is thought that garlic juice has favorable effects in preventing changes in blood glucose levels, body and pancreas weights, and the histopathological changes in pancreas in STZ-induced diabetes.
Fateme Aboutalebi, Homayoun Khazali,
Volume 13, Issue 2 (8-2009)
Abstract

Introduction: The existence of a close relationship between energy status and reproductive function is well documented, but its underlying mechanisms remain to be fully unfolded.Galanin is an orexigenic agent and has been demonstrated as putative regulator of gonadotropin secretion in rats. There is no study to show the interaction of different levels of energy intake and galanin on gonadotropins secretion in ruminants, therefore the goal of this study was to determine whether galanin affects the mean plasma concentrations of LH and FSH in the female saanen goats fed different energy content in diets. Methods: Nine female saanen goats were randomly divided into 3 groups.Animals of all groups were fed either 50% , 100% and 150% energy content in diet for a month.After a month, goats were received 1μg galanin /kg body weight into their jugular vein.Blood samples were collected every 30 minutes from jugular vein of all goats 3.5h before and 3.5h after injection of galanin.Blood plasma were assayed for plasma LH and FSH concentrations by RIA. Results: Injection of galanin only in 150% dietary energy intake significantly decreased the mean plasma concentrations of LH and FSH whereas in 50% and 100% dietary energy intake , injection of galanin had no effect on the mean plasma concentrations of LH and FSH. Conclusion: These results indicated that galanin may negatively affects mean plasma concentrations of LH and FSH in the female saanen goats only with positive energy balance.
Akram Abdolahnejad, Ali Gol, Shahriar Dabiri,
Volume 13, Issue 3 (11-2009)
Abstract

Introduction: Diabetes mellitus has adverse effects on male sexual and reproductive functions in human and animals. Diabetes results in reduced fertility and libido. Medicinal plants have attracted much attention in controlling many diseases such as diabetes. In the present study, we aimed to investigate the effect of garlic juice on testicular damage. Methods: Forty male rats (250±20) were divided into 5 groups as follows: 1- Group normal (N) 2- Group Normal+Garlic (N+G) received garlic juice for 6 weeks. 3- Diabetic (D) received streptozotocin (STZ), 60mg/kg BW/i.p. 4- Group diabetic+garlic before (D+Gb) received garlic juice for 3 weeks before STZ injection and continued for more 3 weeks. 5- Group diabetic+garlic after (D+Ga) three days after STZ injection, they received garlic juice for 3 weeks. Garlic juice was given by gavage (1ml/100g BW). Number of leydig cells, testis weight, serum levels of testosterone and estradiol were assessed. Results: diabetic rats showed a marked decrease in the number of leydig cells, testis weight, serum levels of testosterone and estradiol. Garlic juice significantly increased the number of leydig cells, testis weight, serum levels of testosterone and estradiol in group 4 and 5 compared to group 3. The diabetic group receiving garlic before STZ injection showed more amelioration in complications than that receiving it after STZ injection. Conclusion: these results suggest that garlic juice supplementation could play both preventive and therapeutic role on testicular damage in diabetic rats.
Farinaz Nasirinezhad, Fatemeh Mirzakoochak Khoshnevis, Kazem Parivar, Ghoramreza Amin,
Volume 13, Issue 3 (11-2009)
Abstract

Introduction: Ruta graveolens (RG) stimulates muscles of the uterus, which in turn may initiate menstrual cycles. RG decreases fertility and may also block the implantation of a fertilized egg. This work was undertaken to examine the possible effect of aqueous extract of RG on the reproductive system of immature female mice. Methods: For this reason, immature female Balb/C mouse aged 4-5 weeks were allocated to experimental, vehicle and control groups. After the determination of the LD50 of RG, which was 620 mg/kg, animals in experimental group were given 310 mg/kg of the aqueous extract of RG by intraperitoneal injections every other day for one week. In the vehicle group, animals received similar amounts of normal saline and the animals in the control group received no treatment. One month after the last injection, animals were deeply anaesthetized and blood was collected by cardiac puncture. Serum was separated and kept at -20°C. Ovaries were also removed at the same time, weighed and kept in Bouin's solution for histological analysis. Results: The results showed a significant decrease (p<0.01) in the number of primordial follicles in the experimental group compared to the group of control. Also the ovarian weight, number of corpus luteum and the diameter of remaining corpus luteum decreased. The reduction of the diameter of corpus luteum was significant (p<0.05) compared to the control animals. The number of atretic graffian follicles was significantly increased (p<0.05), while estrogen levels were significantly decreased (p<0.05) in the experimental group compared to the control. Conclusion: Aqueous extract of RG can interfere with reproductive system function in immature female mice by alterations in sex hormonal level and ovarian morphology and might be useful as an antifertility substance.
Nepton Soltani, Mansoor Keshavarz, Qinghua Wang,
Volume 13, Issue 3 (11-2009)
Abstract

Introduction: Gama amino butyric acid (GABA) is the major inhibitory neurotransmitter in the mammalian nervous system. The concentration of GABA and the number of GABA cell secretion decrease in diabetic patient and experimental diabetes model. The reported effects of GABA activation on insulin secretion from beta cells have been controversial. In this study we investigated if GABA administration in animal diabetes model can change insulin and glucagon secretion and improve some diabetic symptoms. Methods: Twenty fourth-week old NOD mi(Non obese diabetic mice) ce were used. Two months after diabetic induction animals were divided into the two groups. One group received 200 μmol of GABA and the other group received phosphate buffer solution (PBS) for one month. Results: GABA administration could significantly decrease plasma glucose and glucagon level, water consumption and urine volume and body fat distribution in the mesenteric bed and abdominal wall. It also could increase plasma Cpeptide level and it has not effect on food intake. Conclusion: NOD mice is very good genetically model for type one diabetes and GABA administration in this mice could treatment some of diabetic symptom. It seems may be we could use of GABA for treatment of diabetic symptom in future. Keywords: Type one diabetes, GABA, C-peptide, Glocagon, glucose, NOD mice.
Dr Gholamali Jelodar, Dr Saeed Nazifi,
Volume 13, Issue 4 (1-2010)
Abstract

Introduction: Recent increase of endocrine disorders may be correlated to the increased exposure to electromagnetic fields from various instruments. Radiation leakage from microwave oven may be harmful for users. Ladies have the highest levels of contact with microwave ovens. This study was carried out to evaluate the effect of radiation leakage from microwave oven on body weight, cortisol and thyroid hormones. Methods: Radiation leakage of microwave oven was measured by RF measuring instrument. For this study, 20 adult two-month-old female mice weighing 25-28 g were randomly divided in control and test groups. Test group was exposed to 2450 MHZ microwaves produced by a microwave oven 3 times a day, 30 minutes each time. After 60 days, body weights of both groups were determined and blood was collected by heart puncture. Cortisol and thyroid levels were evaluated in serum by an RIA method. Results: radiation leakage from oven showed variation and ranged from 6.5 to 57.5 mW/cm2. Mean body weight changes in test and control groups were 0 and 4.54 grams, respectively. Cortisol (23.6 ± 2.24 vs. 13.6 ± 1.47 ng/ml) and T4 (98.4 ± 7.3 vs. 67.0 ± 5.9 nmol/L) levels were significantly increased in the test group compared to the control group, respectively. Level of T3 did not alter significantly. Conclusion: We found that microwaves leaked from oven decrease body weight and increase T4 and cortisol levels, and therefore have deleterious health effects.
Roshanak Rashedi, Homauon Khazali,
Volume 13, Issue 4 (1-2010)
Abstract

Introduction: Ghrelin is a peptide hormone secreted from the stomach with both endocrine and paracrine effects. Ghrelin and its mRNA as well as growth hormone (GH) secretagogue receptor mRNAs are expressed in the pancreas and islet cells and regulate insulin release. Also the immounoreactivity of ghrelin is proved to be high in the hypothalamus and parts of the brain responsible for the regulation of the HPA axis. However, the effect of ghrelin on insulin and ACTH secretion before puberty in semi ruminant animals has never been examined. Therefore the purpose of the following research was to determine the effect of ghrelin on insulin and ACTH secretion before puberty in camels.
Methods: In this investigation, 12 camels were randomly divided into two groups. Animals in each group were fed with either 50% or 100% energy content in diet for 2 weeks. After 2 weeks camels received 8 μg ghrelin/Kg body weight into their jugular vein for 4 days. Blood samples were collected from jugular vein 20 minutes after injection of ghrelin. Blood plasma was assayed for plasma insulin and ACTH concentrations by a RIA method.
Results: Injection of ghrelin in 50% and 100% dietary energy intake significantly decreased the mean plasma concentrations of insulin and increased ACTH secretion in prepubertal camels.
Conclusion: The results of these experiments showed that ghrelin’s reducing effect on insulin secretion and its increasing effect on ACTH in prepubertal camels in starvation condition depends on the presence of glucose in their bodies.
Banafsheh Ranjbar, Iran Pouraboli, Mitra Mehrabani, Shahriar Dabiri, Abdolreza Javadi,
Volume 14, Issue 1 (3-2010)
Abstract

Introduction: Antioxidant agents have beneficial effects in diabetes mellitus. Daucus carota seeds extract has been shown to possess antioxidant activity. In this study, the effect of the methanolic extract of Daucus carota seeds on carbohydrate metabolism and morphology of pancreas was investigated in type I diabetic male rats. Methods: Type I diabetes mellitus was induced in male Wistar rats by injection of 70 mg/kg, i. p. of streptozotocin. Blood samples were collected from the eye cavernousa sinus, before and 5 days after injections for measurement of glucose and insulin. Diabetes was confirmed in rats that had FBS levels above 250 mg/dl. Diabetic rats were divided to 5 groups that received 100, 200 and 300 mg/kg of the extract, glibenclamide (600 μg/kg) and distilled water (0.5 ml) daily for 6 days by gastric gavage. After 6 days, they were sacrificed by decapitation and fasting blood samples were collected and serum levels of glucose and insulin were measured by spectrophotometric and ELISA methods, respectively, by using commercial kits. The pancreas of the rats were dissected out and fixed in 10% formaldehyde for histological studies. Results: Administration of all doses of Daucus carota seeds extract and glibenclamide for 6 days significantly decreased serum glucose levels, however, only 300 mg/kg of the extract as well as glibenclamide significantly increased insulin serum levels. Furthermore the extract and glybenclamide improved pancreas asinuses and islets as the number of islets significantly increased in rats receiving 100 mg/kg of the extract or glibenclamide. Conclusion: D. carota seeds extract has hypoglycemic effect by increasing insulin secretion and improvement of the pancreas.
Masoumeh Motamedi Joibari, Homayoon Khazali,
Volume 14, Issue 2 (7-2010)
Abstract

Introduction: ghrelin is a potent orexigenic agent in rodents and humans. Some studies have shown that ghrelin participates in the adaptive response to weight loss and plasma concentration of ghrelin rises with dieting. On the other hand, weight loss and fasting is accompanied by increased levels of epinephrine and cortisol. In this study, we investigated the effects of epinephrine and cortisol on fasting-induced ghrelin secretion in rats fed different levels of their energy requirements. Methods: forty five male Wistar rats (300-350 g, 15 per group) were fed a diet containing 100%, 50% and 25% of their energy requirement for 10 days followed by 2 days of fasting. Animals were then anesthetized for carotid artery cannulation, which was used for injections and blood samplings. Rats received either 3 μg epinephrine (Ep)/Kg BW, 3 μg cortisol (Cor)/Kg BW, or a combination of these two (0.1 mg in 1 ml of PBS). Blood samples were collected before injections and 30, 60, and 120 min after injections. Results: mean plasma concentration of baseline ghrelin increased in the animals fed 50% food restriction (P≤0.01). In 100% and 50% food restricted groups, fasting ghrelin levels fell after epinephrine and combination of epinephrine and cortisol injection (P≤0.05). In contrast, the group that had 25% food restriction did not show any response to epinephrine and combination of epinephrine and cortisol (P>0.05), while the levels of the fasting ghrelin rose significantly after cortisol treatment (P≤0.01). Conclusion: These results indicate that injection of epinephrine suppresses starvation-induced secretion of ghrelin in normal (100%) and starved (50%) rats. Ghrelin secretion response to epinephrine might be affected by weight loss as it does not seem to be suppressed in starved (25%) rats.
Sepideh Khaksar, Mahnaz Kesmati, Anahita Rezaie, Abdolrahman Rasekh,
Volume 14, Issue 3 (10-2010)
Abstract

Introduction: Impaired wound healing in diabetic patients is a major clinical problem, which is associated with significant morbidity and mortality. Estrogen has positive effects on neoangiogenesis, reepithelialization and cell proliferation. In this research, effect of estrogen on wound healing in diabetic male rats was investigated. Methods: This study was performed on male Wistar rats (body weight 200±20 g), which were divided into 2 groups of normal and diabetic rats. Each group was divided into 3 subgroups of control, sham and test. A circular full-thickness wound with a diameter of 1.5 cm was created on the back of streptozotocin(stz)-induced diabetic as well as nondiabetic rats. Estradiol benzoate (10 μg/sc) was daily administered to test subgroups for 28 days, while the sham subgroups received injections of placebo. The control subgroup did not receive anything. Size measurement and pathological evaluation of the wound was performed on days 3, 5, 7, 14, 21, 28. Results: In the macroscopic study, there was a delay in the wound healing of diabetic group in comparison with normal group. From day 7, wound healing had considerable change in estradiol subgroups in both normal and diabetic rats (p<0.05). In the microscopic study, coating tissue reorganization, granulation tissue and neoangiogenesis formation were surveyed as semi-quantitative parameters. In all cases, estradiol receiving subgroups showed impressive improvement compared to the sham subgroup. Conclusion: This research finds that estrogen can improve the impaired wound healing of diabetic rats and this effect is related with the rate of wound healing and wound structure.
Shoeib Rezaee, Sedighe Kahrizi, Mehdi Hedayati,
Volume 14, Issue 4 (1-2011)
Abstract

Introduction: This research was aimed at examining acute responses of hormones such as growth hormone (GH), total testosterone (TT), free testosterone (FT), free fatty acid (FFA) and cortisol to resistance (R), endurance (E) and endurance-resistance (ER) exercise. Methods: The participants of this study were 10 healthy young men. R protocol included bench press, lateral pull down, leg extension and leg curl. E protocol comprised of 30 minutes pedaling by cycle ergometer at 70% maximum heart rate. In the ER protocol, the participants first went through the E protocol and after an interval of 15 minutes they performed the R protocol. In the control group they did not do any exercise. Blood samples were collected before, immediately after and 15 minutes after exercise. Results: Results indicated that GH and FT were significantly increased after all 3 protocols (P<0.05). TT and FFA were significantly increased after R and E protocols, respectively (P<0.05). Comparison between groups indicated a significant difference between GH and FT. Cortisol was significantly decreased in the E and ER protocols and the control group (P<0.05) but it did not have a significant decrease in the R protocol. Conclusion: The E and ER protocols can increase GH with lower lactate and cortisol production, while the R protocol provides better anabolic environment for development and hypertrophy of muscle fiber because of higher stress, metabolic and hormonal responses. The increase of FFA after the E protocol was probably the cause of reduction of GH and TT secretion in the ER protocol.
Mohammad Reza Jafarzadeh Shirazi, Mohammad Reza Namavar, Amin Tamadon,
Volume 15, Issue 1 (4-2011)
Abstract

Introduction: Gonadotropin inhibitory hormone (GnIH) has been known as a key inhibitor of the secretion of gonadotropin releasing hormone (GnRH). Ewe has estrous cycles comprising of follicular and luteal phases. Follicular phase is in turn divided into proestrous and estrous phases. Blood level of LH increases in follicular and decreases in luteal phases. The aim of the present study was to evaluate (1) the presence of GnIH neurons in the ewe preoptic area (POA) and (2) the alterations of GnIH expression during different phases of ewe estrous cycle. Methods: Three fertile three-year-old ewes in each phase (n=9) were selected and the number of GnIH neurons was estimated by using immunohistochemistry method. Results: GnIH neurons were present in the POA during different phases of estrous cycle. The number of GnIH neurons significantly increased in the luteal phase in comparison with the proestrous phase (P=0.001). Conclusion: GnIH expression in the neurons of POA of ewe is increased in the luteal phase compared to the follicular phase. This can inhibit GnRH secretion in POA and reduce LH secretion during the luteal phase.
Esmaeil Mohamadizadeh, Namdar Yousofvand, Maryam Kazemi,
Volume 15, Issue 2 (8-2011)
Abstract

Introduction: Thyroid hormones play an important role in the regulation of metabolism, maturity and reproduction. Thyroid dysfunction affects almost all endocrine glands such as pituitary and testis. The aim of this study was to investigate alterations of testosterone and luteinizing hormone (LH) serum levels as well as weights of thyroid gland and testes in methimazole (MMI)-induced hypothyroidism. Methods: Twenty-one adult male rats weighing 185 g were divided into 3 groups. The control group received drinking water, while treated groups received two doses of methimazole low dose (20 mg/dl in drinking water) and high dose (100 mg/dl in drinking water), for 42 days. At the end of the experiments, rats were anesthetized and sacrificed and serum samples were obtained. Serum levels of hormones were measured by radioimmunoassay. Weights of testes and thyroid gland were determined after sacrifice. Results: Results showed that the use of methimazole decreased serum levels of T4, T3, testosterone and LH as well as the weight of testes, while it increased the weight of thyroid gland compared to control group. These effects were more clear in the high dose group. Conclusion: This study suggests that MMI–induced hypothyroidism causes a significant decrease in serum levels of thyroid hormones, testosterone and LH. Hypothyroidism also decreases the weight of testes, while it increases the weight of thyroid in rat. These effects were dose-dependent.

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