Insulin resistance is present in patients with Type 2 diabetes mellitus as well as in obese patients without diabetes. The aim of our study was to compare insulin action in diabetic and control persons with or without obesity and to evaluate the influence of serum cholesterol, serum triglyceride and blood pressure on metabolic variables of insulin action. We examined 42 Type 2 diabetic patients and 41 control persons with body mass index (BMI) from 21.1 to 64.5 kg.m-2, and 33 to 71 years old. The isoglycemic hyperinsulinemic clamp technique was performed at an insulin infusion rate of 1 mU.kg-1.min-1 during 120 min. We evaluated the metabolic clearance rate of glucose (MCRG, ml.kg-1.min-1) as the most important indicator of insulin action by isoglycemic clamp. The Pearson's correlation and multiple regression models were used to compare studied factors with the insulin action. We found following predictors of insulin resistance expressed in the relationship with MCRG: BMI (r = -0.68, p<0.001), plasma glucose concentration (r = -0.66, p<0.001), cholesterol (r=-0.55, p<0.001), triglycerides (r = -0.54, p<0.001) and mean blood pressure (r = -0.38, p<0.01). From the multiple regression analysis we conclude that obesity may have even greater influence on the insulin action than diabetes mellitus itself., G. Šindelka, J. Škrha, M. Prázný, T. Haas., and Obsahuje bibliografii
This study aimed to investigate whether heat stress (HS) prevents a decrease in succinate dehydrogenase (SDH) activity and heat shock protein 60 (HSP60) and superoxide dismutase 2 (SOD2) contents in the extensor digitorum longus of streptozotocin (STZ)-induced diabetic rats. Twelve-week-old male Wistar rats were assigned to one of the four groups (n=6/group): control (Con), HS, diabetes mellitus (DM), and diabetes mellitus and heat stress (DM+HS). Diabetes was induced by the administration of STZ (50 mg/kg). HS was initiated 7 days after STZ treatment and performed at 42 °C for 30 min 5 times a week for 3 weeks. SDH activity was decreased in the DM and DM+HS groups. However, SDH activity was greater in the DM+HS group than in the DM group. Although HSP60 content was lower in the DM group than in the Con group, it was maintained in the DM+HS groups and was higher than that in the DM group. SOD2 content was decreased only in the DM group. These findings suggest that HS prevents the decrease in SDH activity in the skeletal muscle induced by DM. According to this mechanism, the maintenance of SOD2 and HSP60 by HS may suppress the increase in oxidative stress., K. Nonaka, S. Une, M. Komatsu, R. Yamaji, J. Akiyama., and Seznam literatury
We studied the effects of administration of b-resorcylidene aminoguanidine (RAG) to Wistar strain rats with experimental diabetes mellitus (DM) induced by streptozotocin. The effects studied included antioxidant levels in plasma and the liver, oxidative damage of lipids represented by the formation of substances reacting with thiobarbituric acid (TBARP) and selected biochemical indicators. The administration of RAG did not significantly affect antioxidant status of diabetic rats or hemoglobin glycation and plasma concentration of fructosamine. In diabetic rats, application of RAG decreased formation of TBARP in plasma but not in the liver. Moderate steatosis of liver and increased plasma levels of triacylglycerols in diabetic rats were significantly improved by application of RAG., A. Liptáková, J. Čársky, O. Uličná, O. Vančová, P. Božek, Z. Ďuračková., and Obsahuje bibliografii
An ethanol vapor concentration of 1.6 mmol/l was used to test the diurnal variations of the olfactory response in two groups of snails, which were adapted to different light-dark cycles. The results revealed that the olfactory sensitivity to stimulation with ethanol was significantly increased during the day-time, which corresponds to the scotophase of the light-dark cycle, to which the animals had been adapted (c2-test, P < 0.01)., M. Voss, C. Büchert, C. Missfelder., and Obsahuje bibliografii