مجله غدد درون ریز و متابولیسم ایران
سال بیست و یکم شماره 1 (پیاپی 103، فروردین و اردیبهشت 1398)

Increased oxidative stress is involved in the pathology of cardiovascular disease. Transient congenital hypothyroidism (TCH) leads to a variety of heart disorders during adulthood. In this study, the effect of TCH on antioxidant and oxidant systems in the serum and left cardiac ventricle of adult male rats was investigated. TCH was induced by administrating 6-propyl-2-thiouracil in the drinking water of pregnant Wistar rats throughout pregnancy, while pregnant rats in the control group consumed only tap water. Superoxide dismutase, catalase (CAT) enzymes, total antioxidant capacity (TAC) and malondialdehyde were measured in the serum and the left ventricles of adult (16 weeks) male offspring. Lipid peroxidation index (LPI) was calculated in serum and cardiac tissue. The results of this study show that CAT activity, TAC level and also LPI in the serum of rats in the TCH group were significantly higher than in controls. In the left ventricular tissue of the TCH group, compared to the control group, CAT activity (107.5±13.1 vs. 159.6±12.3 KU/L, P=0.013) and TAC levels (172.2±7.6 vs. 235.6±13.1 µmol/L, P=0.001) were significantly lower. Decreased CAT activity and TAC in left ventricular cardiac tissue show that TCH can lead to increased oxidative stress of cardiac tissue in offspring. Increased cardiac oxidative stress may therefore contribute to the decreased cardiac function observed in patients with TCH.

Although variants in the FTO gene have been found to be associated with susceptibility to obesity, however, recent studies suggest that dietary intakes may modify the association. This study aimed to investigate the interaction of the Mediterranean dietary pattern (MD) and fiber intake with FTO gene polymorphisms in relation to obesity phenotypes. Participants of this nested case-control study (n=1254) were selected among adult participants of the Tehran Lipid and Glucose Study. All (n=627, generally obese, BMI≥30 kg/m2) were individually matched with controls (n=627, normal weight). Six selected SNPs (rs1421085, rs1121980, rs17817449, rs8050136, rs9939973, and rs3751812) were genotyped. The MD score was computed and Genetic Risk Scores (GRS) were calculated using the weighted method. Adherence to the MD could modify the association of three SNPs (rs17817449, rs8050136, and rs3751812) with general and abdominal obesity (Waist circumference≥95 cm) (P interact ion=Pi<0.05). The odds of abdominal obesity in risk allele carriers of rs3751812 (TG+TT) decreased along with increasing dietary fiber intake (Pi=0.01), compared to subjects with no risk alleles. The risk of general obesity in participants with a high GRS decreased during the MD score quartiles, compared to those with a low GRS (Pi<0.05). The risk of developing general obesity in people with GRS≥6 was reduced by increasing fiber intakes (P trend<0.05). A higher adherence to the MD pattern and fiber intakes can decrease obesity risk in risk allele carriers of three FTO polymorphisms, rs17817449, rs8050136 and rs3751812.

Resistin is a peptide hormone, secreted by adipose tissue. Increased secretion of resistin results in insulin resistance and metabolic syndrome. The aim of this study was to determine the effect of hydro-alcoholic spinach (Spinacia oleraceae L.) extract on the expression of resistin mRNA in the visceral adipose tissue of rats exposed to chronic immobilization stress. In this experimental study, 30 adult male Wistar rats were allocated to six groups, including: 1) Control, 2) Spinach 200, 3) Spinach 400, 4) Stress, 5) Stress-Spinach 200 and 6) Stress-Spinach 400. Groups 2 and 5 were gavaged with spinach hydro-alcoholic extract at dose 200 mg/kg body weight and groups 3, 6 were gavaged with dose 400 mg/kg body weight of extract for 21 consecutive days; groups 4, 5 and 6 were placed in restrainers 6 hours a day for 21 consecutive days. At the end of this period, the expression of resistin mRNA in adipose tissue was evaluated by Real Time PCR. Data analysis was performed using one-way ANOVA and P<0.05 was considered significant. Chronic immobility increased the expression of resistin mRNA (2.78±0.30) in adipose tissue, compared to the control group (1±0.36) (P=0.002). Resistin mRNA expression in visceral adipose tissue of Stress-Spinach 200 and Stress-Spinach 200 (0.74±0.23 and 1.45±0.15 respectively) was lower than in the stress group (P=0.000 and P=0.020 respectively). Results indicate that spinach extract can reduce resistin mRNA expression in rats exposed to chronic restraint stress.

In the present study the effect of chronic maternal high-fat diet consumption on energy homeostasis and glucose metabolism in response to chronic stress was investigated in adult male rats. Female rats were divided into two groups of normal and high fat diets. Each group received their diet from 3 weeks before pregnancy until the end of lactation. At 8 weeks of age, male offspring were divided into control and stress groups, the stress group receiving variable stress for 2 weeks. At the end of 10 weeks, plasma concentrations of glucose, insulin, corticosterone and leptin were measured and intra-abdominal fat was weighed in all male offspring. The body weight, food and calorie intake of the rats were also measured. Maternal high-fat diet alone reduced intra-abdominal fat weight, plasma concentrations of corticosterone and leptin, body weight, food and calorie intake, although at had no effect on fasting plasma glucose and insulin concentrations, or on HOMA-IR index. In response to stress, the maternal high-fat diet reduced corticosterone and leptin plasma concentrations, body weight, food and calorie intake compared to the control group; whereas did not significantly change the intra-abdominal fat weight, plasma glucose and insulin levels as well as HOMA-IR index. From the results of the present study it seems we can conclude that maternal HFD feeding, in a critical developmental period (perinatal), by altering responsiveness of hypothalamic-pituitary-adrenal axis and/or central leptin sensitivity, exacerbates impaired energy homeostasis in stressed adult offspring.

Obesity is linked to cardiovascular diseases, characterized by endothelial dysfunction, the optimal mode of exercise for controlling obesity of high-intensity interval training or moderate-intensity continuous training has is the however not yet been determined. A total of 33 inactive and overweight women, aged 40-50 years with body mass index over 27kg/m2 were randomized to high-intensity interval training, moderate-intensity continuous training or controls. The exercise intervention consisted of 12 weeks of training, and 3 supervised sessions per week. The moderate-intensity group trained continuously for 47 min at 60–70% of maximum heart rate,while high-intensity training consisted 4×4min durations at 85–95% of maximum heart rate with 3 min active breaks in between these, consisting of walking or jogging at 50–60% of maximum heart rate. Protocols were isocaloric. Before and after the completion of the exercise program, blood samples of the subjects were tested for evaluation of lipid profiles and endothelial progenitor cells (CD34, CD133, and CD309). Analysis of variance (ANOVA) and T-student test were applied for data analysis by SPSS version 20 (P<0.05). According to our findings, changes of CD133 in both training groups was statistically significant (P=0.006).The CD309 index increased significantly only in the moderate-intensity continuous training group (P=0.002), whereas changes of CD34 were not statistically significant (P=0.094). Twelve weeks of training exercises, especially high-intensity interval training, may improve some of the markers of endothelial progenitor cells in overweight women, indicating that regular and prolonged exercise can probably be a preventative factor in the incidence of cardiovascular disease.

Diabetic foot ulcer is a serious complication of diabetes mellitus; it consists of lesions in the deep tissues associated with neurological disorders and peripheral vascular disease in the lower limbs. Delayed wound healing in diabetes leads to long-term hospitalization and even amputation of distal organs. Diabetes mellitus is associated with decreased nitric oxide bioavailability that causes dysfunction of the skin. Nitric oxide, a short-lived free radical, is produced in the skin, where it has important physiological functions. Much evidence suggests that nitric oxide accelerates wound healing. This review describes the pathways of nitric oxide production in the skin as well as role of nitric oxide donors in diabetic wound healing. Increased oxidative stress and arginase activity contribute to decreased nitric oxide bioavailability in diabetes. Based on data available, nitric oxide donors such as nitrite increase nitric oxide levels in the diabetic wound and improve would healing. It seems that increased nitric oxide in diabetic patients improves wound healing by increased collagen deposition and keratinocytes proliferation in the wound edges there by increasing reepithelialization capacity, chemoattractant of cytokines, increased formation of small blood vessels and increased blood flow to the wound site. In conclusion, nitric oxide donors could be considered as a potential and cost-effective treatment for diabetic wounds.