[ review of models of hypothyroidism in the rat: comparison of the thyroid function in rats and humans]

Human subjects can not always used as models for studying disease by researchers because of the potential risks for human health, and in addition, control of interfering factors is not easy in these subjects. Animal biology, physiology, anatomy, biochemistry, pharmacology, and genetics are very similar to humans. Animals are suitable models for research, as their functional body system is similar to humans and is easily manipulated. Most of our current knowledge in medical sciences is obtained from animal studies, among which, rats and mice are mostly used for the their shorter lifespans, which creates the possibility of producing many generations and studying total lifespan. The thyroid plays pivotal role in the body and is vital for normal function of almost all tissues throughout life. Decreased secretion of thyroid hormones from the thyroid gland [hypothyroidism] is a prevalent disorder and as a result animal models of hypothyroidism are often very important for research purposes. Thyroidectomy, genetic manipulation, and using anti-thyroid drugs are the most important ways to induce hypothyroidism in animals. The aim of this study was to review and evaluate different models for induction of hypothyroidism in rat, and in addition to compare the characteristics of rat and human thyroid glands. Anti-thyroid drugs could be used as cheap, available, and simple methods for inducing hypothyroidism, although they may also affect the function of other organs

[ review of hyperthyroidism models in mouse and rat]

Humans can rarely be used as experimental models in medical researches, because of ethical issues. Therefore, some animal models, which have physiological systems similar to humans, are commonly used. In this regard, rats and mice are the most favorable species in research models. The thyroid gland has a key role in human growth and development and is essential for normal functioning of the body systems and tissues. The aim of this study was to review rat and mouse models of hyperthyroidism. Related articles published between 1975-2014 on hyperthyroidism in rat and mice were searched in Pub Med. Hyperthyroidism can be induced in animals using different doses of thyroid hormons [T3 and T4] by oral administration, injection, or with the diet. In addition, transgenic mice could act as a model of hyperthyroidism for the design of specific model of hyperthyroidism, such as Graves' disease. Animal models of hyperthyroidism could be used for studying the disease, treatment and identification of the molecular mechanisms involved. Pharmacologic agents are mostly used for creating animals models of hyperthyroidism because of their easy availability and low cost, compared to genetic techniques that are costly and expensive

Menarcheal age of mothers and daughters: Tehran Lipid and Glucose Study

There is some evidence for a decreasing age of menarche in many populations. This study examined the secular trend of age at menarche among Iranian women. Age at menarche based on recall information was recorded for 770 pairs of mother and daughters. Between 1930 and 1990 mean menarcheal age of this cohort of women decreased from 13.88 to 12.98 years [-0.15 years per decade] and mean height of the cohort increased from 152.33 to 158.43 cm [+0.99 cm per decade]. There was a significant correlation between menarcheal age of mothers and their daughters [r = 0.27]. Year of birth, mother's menarcheal age and daughter's height were significant predictors of daughter's menarcheal age

Relationship between dhea and dhea-s with anthropometric indices in women with different grades of obesity

Dehydroepiandrosterone [DHEA] and dehydroepiandrosterone sulfate [DHEA-S] are the most abundant steroids in human plasma. The aim of this study was to evaluate the relationship between DHEA and DHEA-S and anthropometric indices in women with different grades of obesity. This cross- sectional study investigated 170 women; 35 normal weight [BMI= 18.9-24.9], 33 overweight, [BMI = 25-29.9] as 36 women [BMI= 30-34.9] as obese grade I, 33 [BMI = 35-39.9] as obese grade II and 33 [BMI>40] as obese grade III. Body mass index was defined as weight in kilograms divided by the square of the height in meters. Serum levels of dehydroepiandrosterone, dehydroepiandrosterone sulfate and glucose were measured by commercially available enzyme immunoassay kits and the glucose oxidase method, respectively. There was a negative and significant correlation between DHEA and age in the normal [r=-0.457, P=0.006] overweight [r=-0.414, P=0.017] obese l [r=-0.402, P=0.015] obese ll [r=-0.391, P=0.024] and obese III [r=-0.354, P=0.043] groups, respectively. Also a negative and significant correlation was found between DHEA-S and age in overweight [r=-0.394, P=0.019], obese grade I [r=-0.455, P=0.005] and obese grade II [r=-0.390, P=0.023] groups respectively. We found a positive and significant correlation between DHEA and frame size in individuals of the Obese I, Obese II and Obese III groups, and also a positive and significant correlation between DHEA-S and frame sizes in individuals of these three groups. Results showed that serum levels of DHEA decrease with increasing grades of obesity, whereas serum levels of DHEA-S increase with increasing obesity

[Reversibility of physical and psychological stress effects on contractility of isolated aorta and serum corticosterone levels one month after stress in rat]

Although data shows the effects of stress on the cardiovascular system, there is no information on their reversibility. The aim of this study is to determine the reversibility of stress effects on resposiveness of isolated rat aorta. Thirty-six male rats were divided into three groups, the control, physical stress, and psychological stress groups. During study animals were kept in 12h/12h light/dark cycles at 23 +/- 2 °C and had free access to food and water. Stress was induced by the Communication Box for three weeks. Physical stress applied with electrical current [1mA, 1hz, 10 sec/min] applied one hour twice daily. After one month recovery post stress responsiveness of isolated aorta to potassium chloride and phenylephrine were determined. The results of this study showed that one month recovery, following stress reverse, serum corticosterone and isolated aortic contractility in rats, so that no significant differences were observed between the control and stress groups; the decreased adrenal weight coused by physical stress also reversed to normal one month after stopping the stress. It can be concluded that effects of physical and psychological stress on isolated aortic tensions is not permanent, and can be reversed

[ effects of orally administrated magnesium on isolated aorta contractility in streptozotocin induced diabetic rats]

Some studies suggest that magnesium deficiency contributes to the cardiovascular complications associated with diabetes mellitus. Hence the present study investigated the effects of orally administrated magnesium on isolated aorta contractility in response to KCI and Phenylephrine [Phe]. Sixty male Wister rats [180-250 g] were divided into two diabetic and two control groups. One sub group of each received magnesium sulfate in their drinking water, while two other groups, had only tap water. After 8 weeks, thoracic aorta was isolated, cut into 2-3 mm rings and mounted in an organ bath. The tissue was then exposed to cumulative doses of KCI [10, 20, 40, 60 and 80mM] and Phe [10-9, 10-8, 10-7, 10-6, and 10-5M] and contractions were measured by an isometric transducer. During the mentioned time, fasting blood samples were drawn every 2 weeks to measure plasma glucose level. Vasoconstrictive responses to KCI and Phe were significantly higher in control groups, compared to diabetic groups [P<.05] and there were no significant differences between Mg-treated and non Mg-treated rats. Maximal contractions to KCI were 2.91 +/- 0.31, 2.79 +/- 0.18, 2.37 +/- 0.16 and 2.42 +/- 0.11 and the maximal responses to Phe were 3.25 +/- 0.17, 3.12 +/- 0.25, 2.57 +/- 0.33 and 2.73 +/- .21 in control, Mg-treated control, diabetes and Mg-treated diabetic groups, respectively. No significant difference was found in plasma glucose between Mg-treated groups and non mg-treated groups. Oral administration of magnesium for 8 weeks has no effect on isolated aorta contractility in diabetic rats

[Changes of serum leptin levels in healthy women with different grades of obesity and its correlation with hormonal and anthropometric factors]

Obesity is associated with a number of endocrine and metabolic abnormalities. Leptin is a peptide that is strongly correlated with adiposity and is a potential determinant of obesity and its complications. The aim of this study was to evaluate the relationship between serum leptin levels with anthropometric and hormonal factors in healthy women with different grades of obesity. This cross- sectional study enrolled 38 women with BMI ranging between 18.9-24.9, as the normal weight group, 35 women with BMI 24.9-29.9, as overweight, 37 women with 29.9-34.9, as obese grade I and 34 women with BMI 34.9-39.9, as obese grade II. Body Mass Index was defined as the weight in kilograms divided by the square of the height in meters. Serum levels of dehydroepiandrosterone sulfate, insulin, cortisol and Leptin were measured by commercially available enzyme immunoassay kits. There was a dramatic, continuous increase in serum leptin concentration when the degree of obesity was increased and concordance was seen with serum insulin concentrations. There was a direct and significant correlation between serum leptin concentration and BMI in obese subjects[r= 0.736, P< 0.001]. We found significant correlation between dehydroepiandrosterone sulfate concentrations and cortisol [r= 0.237, P< 0.05]. There was a significant negative correlation between leptin and insulin in grade 2 obese subjects[r= - 0.566, p< 0.05] and a significant positive correlation between cortisol and dehydroepiandrosterone sulfate in grade 2 obese subjects [r=0.610, P<0.001]. Serum leptin levels continuously rose with increasing degrees of obesity and serum leptin concentrations were strongly correlated with BMI. Concentrations of insulin and cortisol increase with increasing serum leptin levels

[Comparison of serum leptin levels of non-diabetic and diabetic obese subjects and its relationship to anthropometric indices]

Leptin, the product of the ob gene, plays a significant role in the pathogenesis of obesity and type 2 diabetes mellitus. The aim of this study was to compare serum leptin level in non-diabetic and type 2 diabetic obese subjects and assess its relationship to anthropometric indices. This cross-sectional study was performed on 35 obese subjects with type 2 diabetes and 35 non-obese, non-diabetics. Fasting lipid profiles were measured using enzymatic methods. The NycoCard HbA1c Kit was used to measure HbA1c. Serum leptin, insulin and glucose levels were measured by an enzyme immunoassay, using a commercially available kit and glucose oxidase methods respectively. The insulin resistance index was calculated by homeostasis model assessment [HOMA-IR]. The mean of insulin resistance index [HOMA-IR], HbA1c, diastolic blood pressure, triglyceride and fasting glucose in diabetics were significantly higher than in non-diabetic subjects [P < 0.05]. Serum leptin levels were significantly lower in diabetics than in non-diabetics [21.51 +/- 2.18 vs. 30.36 +/- 2.46] and were significantly higher in women than in men [31.85 +/- 17.96 vs.12.80 +/- 9.02] in the diabetic and [36.11 +/- 10.99 vs. 23.55 +/- 15.72] in non-diabetic groups. There was a direct and significant correlation between serum leptin levels with hip circumference [r= 0.450, p= 0.04] in diabetics and [r=0.590, p=0.000] in non-diabetics, and between leptin and BMI [r= 0.666, p= 0.000] in diabetic and [r= 0.490, p= 0.003] in non-diabetic groups. Since the mean serum leptin level is lower in obese diabetes, compared to non-diabetics, further studies are required to clarify the mechanisms of lower leptin levels in obese diabetic subjects

[Inhibitory effect of GABA on glucose- stimulated insulin secretion from isolated islets of langerhans in rat]

Gamma-amino butyric acid [GABA], an amino acid, present in some inhibitory neurons of the central nervous system, is also found in relatively high levels in the islets of Langerhans. Results of different studies concerning the effect of GABA on insulin secretion are controversial. The aim of this study was to determine the role of GABA and GABAB receptors on glucose-stimulated insulin secretion in isolated islets of rats. The collagenase digestion technique was used to isolate the islets from pancreata of 45 male Wistar rats [200-250g]. Insulin secretion was assessed in eight islets in each cup exposed to different concentrations of glucose [8.3 and 16.7 mM] in the presence or absence of GABA [25, 50, 100 micro M], baclofen [10, 20, 50 micro M] [GABAB agonist] and saclofen [50,100 micro M] [GABAB antagonist]. Insulin concentration was measured by the ELISA method. Insulin release was reported as mean +/- SEM micro U/isIet/50 min and p values of <0.05 were considered significant. GABA inhibited glucose [8.3 and 16.7 mM]-induced insulin secretion in isolated islets [P<0.05]. Different concentrations of baclofen had no significant effect on glucose-induced insulin secretion; however glucose [16.7 mM] stimulated insulin secretion in the presence of 100 micro M saclofen [91 +/- 8.8 micro U/islet/60 min] was significantly [p<0.05] higher compared to insulin secretion stimulated by 16.7 mM glucose alone [67.7 +/- 2.58 micro U/islet/60 min]. These findings indicate that GABA has an inhibitory effect on glucose-induced insulin secretion; and therefore it may play a regulatory role in insulin secretion. This effect needs to be taken in to account in the pathophysiology of diabetes

[ effect of parental morphine addiction on rat's reproduction rate and pituitary - gonadal axis hormone profile of their adult offspring]

Opiates such as morphine administration, decrease serum level of pituitary-gonadal axis hormones in both sexes. On the other hand, morphine can be transferred from the mother the fetus and neonate via the placenta and milk. Thus maternal exposure to morphine during pregnancy and weaning may affect serum level of pituitary-gonadal axis hormones in off springs. Focus on the effect of the addiction of the pregnant mother on the health of the fetus and neonate has led to under recognition of possible male mediated effects. In this study, the effect of morphine addiction of the parents on the reproduction rate and pituitary gonadal axis hormone profile have been investigated. Forty female and 16 male albino Wistar rats [120-140 days old] were enrolled into the study. Animals were addicted by oral administration of incremental dose of morphine in drinking water for 21 days. Then male rats were placed with females in 6 groups: 1- male addict =test, 2-female addict=test 2, 3- male and female addict = test 3, and sham 1, sham 2 and the control group. Morphine administration was also continued during pregnancy and weaning as well. At the time of puberty, blood samples were collected from the off springs and pituitary-gonadal axis hormones were measured. Morphine was in dissolved 3% sucrose and added into the drinking water of groups 1-3. The same amount of sucrose was added into the drinking water of the two sham groups. In female offspring of group 1 [test 1] LH [0.086 +/- 0.04Iu/L] and 17beta estradiol [93.2 +/- 5.92 ng/L] were significantly reduced compared to the control values of 0.19 +/- 0.03 and 182.4 +/- 11.21 respectively. But no pituitary-gonodal axis hormones alteration occurred in male offspring of this group and offspring of group 2. There were no pregnancies in group 3. The results suggest that the female maternal morphine addiction disturb reproduction processes more them does male addiction

[Serum nitric oxide metabolite levels in general healthy population: relation to sex and age]

Interest in measuring of serum nitrite/nitrate [NOx] concentration has increased during recent years as there are reports indicating that NOx levels affected by some diseases. This study was aimed at determining the serum NOx levels in healthy subjects within the framework of a population-based study. This was a descriptive analytical study carried out within the framework of Tehran lipid and glucose study participant. Serum NOx concentration was measured in 3505 subjects aged 20 years and over. The exclusion criteria were high blood pressure, impaired carbohydrate metabolism, dyslipidemia, and renal dysfunction. Afterthat 786 non-smoker healty subjects were in cluded in the analysis. Serum NOx concentration was determined in all samples obtained following an overnight fasting period. The serum level of NOx in different age groups was further compared. Later, comparison between the lowest and highest quartiles of NOx levels was performed for both genders. The mean +/- SD serum NOx concentration was 26.0 +/- 12.9 mmol/l with insignificant difference between men [25.6 +/- 11.8] and women [26.1 +/- 13.3 mmol/l]. No age-related change in serum NOx concentration was observed in either sex. Women and not men with high serum NOx had significantly higher weight, waist circumferences, and systolic blood pressure even after adjustment for menopausal status [p<0.05]. Based on data found in present study it seems that the serum NOx concentration in healthy subjects to be strongly controlled, thus, any significant change in serum level of NOx could be considered as a reflection of altered physiological status

Comparing the effects of physical and psychological stress on responsiveness of isolated rat aorta

Stress, particularly when chronic, has many adverse effects on human health. The role of stress has been elucidated in cardiovascular disorders such as hypertension, myocardial infraction, atherosclerosis, myocardial ischemia, and cardiac arrhythmia. The aim of this study is to determine and compare the effect of chronic physical and psychological stress on the contractility of isolated rat aorta. Male albino Wistar rats weighing 200-250 g were used. Three groups of rats, the physical stress, psychological stress and the control qroups [n = 12 each] were used in this study. Physical and psychological stress were induced using the communication box for three weeks. At the end of the stress period animals were anesthetized, following which the abdomen was opened and the thoracic aorta dissected and endothelium denuded. The aorta ring were connected to isometric transducer and contractions in response to 5- 60 mM potassium chloride and 10-10-10-6 phenylephrine were measured. Serum corticosterone was measured by radioimmunoassay before and after intervention in all groups. In the physical stress group serum corticosterone levels rose from 402 +/- 40 to 721 +/- 94 ng/ml after stress [p < 0.05]. This value in the psychological stress group reached 946 +/- 84 ng/mL from the initial value of 400 +/- 114 ng/mL [p < 0.05]. Aorta responses to potassium chloride and phenylephrine were significantly lower compared to the control group [p < 0.05] in both the stress groups. The results of this study indicate that chronic physical and psychological stress cause an increase in serum corticosterone and decrease aorta responsiveness in isolated rat aorta, implying that psychological stress has detrimental effects on the vascular system similar to those of physical stress

Osmotic fragility of red blood cells of hypothyroid, hyperthyroid patients and control subjects

Many hypo and hyperthyroid patients are anemic. Changes in concentration of thyroid hormones can affect Na+- K+ ATPase number and activity and also phospholipid composition of the cell membranes leading to changes in the surface to volume ratio and strength of membrane. In this study, the osmotic fragility of the red blood cells from non-treated hypo and hyperthyroid patients diagnosed on the basis of clinical examinations and paraclinical data were compared to that of control subjects. Written consent was obtained from all subjects. After washing three times with normal saline, red blood cells were placed in varying sodium chloride [NaCl] concentrations [0-0.9 gr%], following which, fragility was assessed with routine colorimetry methods. To do this, after the incubation period, tubes were centrifuged and the optical densities of the tubes was measured. Hemolysis percent in tubes was calculated on the basis of 100% hemolysis in the tubes containing 0 gr% of NaCl. The results indicate that the osmotic fragility of the cells from hyperthyroid patients in 0. 45gr% NaCl [74.6% +/- 30.2] was significantly [p < 0.01] lower than control subjects [93.8% +/- 9.1]. Osmotic fragility of red blood cells in 0. 5 g percent concentration of sodium chloride in hyperthyroid patients [27.8% +/- 26.0] was significantly less [p < 0.001] compared to the controls [63.5% +/- 27.5]. It appears that this change cannot be explained by changes observed in red blood cell indices [micrococytosis hypochromia]. According to the results of this study one can conclude that anemia reported in hypo- or hyperthyroid patients is not due to high osmotic fragility of the red blood cells and other causes need to be investigated

[Hematology and osmotic fragility of red blood cells in hyperthyroid rats]

Hyperthyroidism is associated with anemia. Since thyroid hormones, by acting on Na+/K+-ATPase activity and numbers, and also on the lipid composition of the membrane can alter the fragility of red cells, in this study, use compared the osmotic fragility of red cells in hyperthyroid rats to that of controls. Forty eight male Wistar rats [body weight, 221 +/- 4g] were divided in 4 groups. Group I consumed L-thyroxine [12mg/L in drinking water] for 30 days, group II was the control for group I, group III consumed L-thyroxine for 60 days and group IV was the control group for the group III. At the end of the intervention period, hormonal and biochemical measurements were done in blood samples. To assess the osmotic fragility, red blood cells [RBC] were incubated at 37°C for 30 min in different concentrations of NaCl and the extent of hemolysis was measured by colorimetry of the supernatant. Hemolysis percent was expressed in terms of percent hemolusis in presence of distilled water [100% hemolysis]. In this study although hemoglobin, haematocrit, mean corpuscular hemoglobin and mean corpuscular volume in group III were significantly [P<0.05] higher compared to group IV, osmotic fragility did not show any significant difference. The results indicate that hyperthyroidism in rat can not anemia and osmotic fragility of RBCs in hyperthyroid animals do not differ from control groups

[ effects of orally administrated magnesium on denuded aorta contractility in streptozotocin induced diabetic rats]

Some studies suggest that magnesium deficiency contributes to the cardiovascular complications associated with diabetes mellitus; hence the present study investigated the effects of long term orally administrated magnesium on isolated denuded aorta contractility in response to KCl and Phenylephrine [Phe]. Sixty male Wister rats [180-250 g] were divided into two diabetic and two control groups. One group of each received magnesium sulfate in their drinking water, while the two other groups, had only tap water. After 8 weeks, thoracic aorta was isolated, cut into 2-3 mm rings, endothelium removed and transferred to an organ bath. The tissue was then exposed to cumulative doses of KCl [10, 20, 40, 60 and 80 mM] and Phe [10-9, 10-8, 10-7, 10-6 and 10-5 M] and contractions were measured by an isometric transducer. During the study period, fasting blood samples were obtained every 2 weeks to measure Plasma Glucose level. Vasoconstrictive responses to KCl and Phe were significantly [p<0.05] higher in the control group as compared to the diabetic groups [p<0.05] and there were no significant differences between Mg-treated and non Mg-treated rats. Maximal contractions to KCl were 2.32 +/- 0.23, 2.76 +/- 0.19, 1.96 +/- 0.11 and 1.84 +/- 0.21 and the maximal responses to Phe were 2.94 +/- 0.24, 3.38 +/- 0.20, 2.24 +/- 0.27and 2.61 +/- .27 in the control, Mg-treated control, diabetics and Mg-treated diabetic groups, respectively. No significant differences were found in plasma glucose concentrations between the Mg-treated and non Mg-treated groups. Oral administration of magnesium for 8 weeks has no effect on isolated denuded aorta contractility in diabetic rats

[Effect of oral administration of propylthiouracil during pregnancy and lactation in female rats on isolated aorta response in their adult male off springs]

Thyroid hormones have extensive effects on differentiation, development, and growth of different organs. Effect of the administration of PTU in pregnant and lactating rats on isolated aorta response of their adult off-springs has been investigated. Three groups of female rats were selected. In the first group, [fetal group], observation of vaginal plug after mating was considered as the first day of pregnancy, and then PTU was added to their drinking water until the end of gestational period. In the second group, PTU was added to the drinking water of female rats from the time of labor for 25 days postpartum, [neonatal group]. The third group was the control group which consumed only drinking water. In all three groups totalþ thyroxine [tT4], free thyroxine [fT4], total triiodothyronine [tT3], free triiodothyronine [fT3] and TSH were measured in the sera obtained from the mothers, immediately after discontinuing the drug. Levels of the above mentioned hormones, [except TSH], in fetal and neonatal groups were significantly lower than control group [p<0.05] TSH in fetal and neonatal groups was significantly higher than controls, [p<0.001]. After two months the adult off springs were anesthetized, dissected and isolated aorta response was examined against KCl and phenylephrine. Results of this study indicated that responsiveness of aorta in fetal group was significantly decreased compared to the control group [p<0.05], but neonatal group had no significant difference with the control group. Hypothyroidism in fetal period has significant effects on differentiation and development of vascular bed, [aorta], in a way that can be still observed during adulthood

[Changes in blood pressure and its association with anthropometric indices and puberty during Ramadan in adolescent girl]

The present study was designed to evaluate blood pressure changes in Tehranian 8-13 y old fasting girls during Ramadan and determine effective factors in order to observe blood pressure alteration independently. Totally, 337 female students aged 8-13 years [mean 10+/-1], were selected by stratified randomized method among volunteer girls intending to fast the whole month of Ramadan. Study was conducted in three stages; before and during the 2nd and 4th weeks of Ramadan. At each visit, systolic and diastolic blood pressure, pulse rate and pulse pressure, and anthropometric indices were recorded. Girls were also evaluated for pubic hair, breast development and menarche. Totally, 283 girls completed all the three stages. Girls had been fasting for 9+/-3 and 25+/-4 days in the 2nd and 3rd visits, respectively. As compared to baseline, there were slight reductions in anthropometric indices during fasting. Mean systolic blood pressure decreased from 102+/-11 mmHg before fasting to 99+/-11 mmHg in the 2nd week of fasting and returned to basal level at the end of Ramadan [p<0.001]. Mean diastolic blood pressure were 70+/-9 and 71+/-8 mmHg before and in the 2nd week of fasting and increased to 74+/-9 mmHg at the end of Ramadan [p<0.001]. Systolic and diastolic pressures were significantly correlated with most anthropometric and pubertal indices. Weight showed the strongest correlation with systolic [r=0.48] and diastolic [r=0.40] blood pressure [p<0.001]. Linear regression analysis demonstrated weight as the best predictor for systolic and diastolic blood pressure. Adjusting systolic and diastolic blood pressure according to the weight of the girls did not cause considerable change in their values and patterns during fasting. Blood pressure changes in Tehranian 8-13 year old girls during Ramadan fasting in autumn season were slight, within normal range and independent from weight changes

[Effect of chronic psychological stress on carbohydrate metabolism in rat]

Several studies have shown that stress has major effects on carbohydrate metabolism. There are some evidences suggesting that stress may induce type 1 and type 2 diabetes mellitus. The effects of psychological stress however need to be investigated. The present study has investigated the role of chronic psychological stress on carbohydrate metabolism in male rats. Animals were assigned in two groups of control and stressed [n=8/group]. The animals of the stressed group were exposed to different restraint stressors [1 hour twice daily] for 15 and 30 days. At the beginning and end of the experimental periods fasting blood samples were obtained by tail snipping and oral glucose tolerance test [OGTT] was carried out. Glucose was measured by glucose oxidase method. Insulin and corticosterone were assayed by their respective RIA kits. Fasting plasma glucose level on the 15th day of the experiment showed significant increase in the stressed rats compared to the controls. The plasma levels of glucose at 15 and 60 min after performing OGTT were significantly increased on the 15th and 30th days of the experiment in the stressed group. Fasting plasma insulin showed significant decrease on the 15th and 30th days of the experiment in the stressed group compared to the controls. On the 15th day of the experiment, at 15 and 60 min after performing OGTT the plasma level of insulin showed significant decrease in the stressed group as compared to the control group. Fasting plasma corticosterone concentration was significantly increased on the 15th day of the experiment in the stressed rats compared with the control rats and the 1st day of the experiment. In the stressed group immediately after stress exposure plasma corticosterone was significantly higher than before stress exposure, only on the 1st day of the experiment. Results have revealed that chronic psychological stress can impair glucose metabolism and this effect may be mediated by changes in insulin and corticosterone secretion. However the role of other stress hormones has to be investigated

Effect of the carbon tetrachloride extract of trigonella foenum graecum seeds on the glycogen content of liver in diabetic rats

Diabetes is a common endocrine disorder. Although the most common conventional treatment for diabetes is insulin, the diet therapy approach has many advantages in developing countries. Among many herbs, reported to possess antidiabetic activity, Trigonella foenum graecum [fenugreek] is one of the best in terms of efficiency and safety. The effect of carbon tetrachloride extract of fenugreek on liver glycogen has not been investigated until now. This study was designed to investigate the effect of carbon tetrachloride fenugreek in extract comparison with insulin on liver glycogen. For this purpose we used 3 groups of rats, each containing 10 animals. Stereptozotocin was administered to induce diabetes. One group served as control group, receiving no treatment; in the 2[nd] group, NPH insulin was administered on 3 consecutive days. For the third group, carbon tetrachloride extract of fenugreek was administered orally for 3 days. Blood glucose was measured before and after intervention. Daily water intake and liver glycogen were assayed at the end of treatment. The results showed that fenugreek extract, like insulin, caused a significant decrease in blood glucose and daily water intake [P<0.05]. A significant increase in liver glycogen, compared with the untreated group, was seen in the insulin and extract treated groups [P<0.05]. In conclusion, the results of this study confirm the benefits of the traditional use of fenugreek for diabetes treatment

[Study on the effects of Chloroformic extract of Securigera Securidaca on serum Glucose level and liver Glycogen content of mice]

Although Securigera securidaca [SS] has long been known for its hypoglycemic effect, the precise nature of its effective component[s] and the involved mechanisms have not been investigated yet. This study investigated the effect of Chloroformic extract of Securigera securidaca seed on fasting serum Glucose and Glucose tolerance test, body weight, food consumption and liver Glycogen content. Chloroformic and hydroalcoholic extracts of the seeds were prepared by the maceration method. Experiments performed on mice of both sexes with the weight range of 25-30 gr. Serum Glucose concentration and liver Glycogen content were measured by O-toluidine and trichloroacetic methods respectively. According to the results, hypoglycemic effect of Chloroformic extract is dose-dependent and it appeared that 3 mg/kg dose of Chloroformic extract has the maximum hypoglycemic effect. Administration of this dose reduced fasting serum Glucose concentration from 103 +/- 3 mg/dl to 69 +/- 3 mg/dl and Glucose tolerance test from 128 +/- 1 mg/dl to 90 +/- 2 mg/dl. 10 days administration of Chloroformic extract also increased food consumption, body weight and Glycogen content of the liver in case group comparing to the control group. In conclusion, the Chloroformic extract of Securigera securidaca seed contains component[s] that after oral administration can cause hypoglycemic effects through either inducing insulin-like effects or increasing insulin release. By identifying and formulating of these components, this plant can be used more efficiently in the treatment of diabetic patients