ABSTRACT
Peripheral insulin resistance in obese/type II diabetes animals results from an impairment of insulin-stimulated glucose uptake into skeletal muscle. Insulin stimulate the translocation of GLUT4 from intracellular location to the plasma membrane. Soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) is implicated in mediation of fusion of GLUT4-containing vesicle with the plasma membrane. Present study investigated regulatory effects of Rhodiola sachalinensis administration and exercise training on the expression of GLUT4 protein and SNAREs protein in skeletal muscles of obese Zucker rats. Experimental animals were randomly assigned into one of five groups ; lean control (LN), obese control (OB), exercise-treated (EXE), Rhodiola sachalinensis-treated (Rho), combine of Rho & EXE (Rho-EXE). All animals of exercise training (EXE, Rho-EXE) performed treadmill running for 8 weeks, and animals of Rho groups (Rho, Rho-EXE) were dosed daily by gastric gavage during the same period. After experiment, blood were taken for analyses of glucose, insulin, and lipids levels. Mitochondrial oxidative enzyme (citrate synthase, CS ; beta-hydroxyacyl-CoA dehydrogenase, beta-HAD) activity were analysed. Skeletal muscles were dissected out for analyses of proteins (GLUT4, VAMP2, syntaxin4, SNAP23). Results are as follows. Exercise and/or Rhodiola sachalinensis administration significantly reduced body weight and improved blood lipids (TG, FFA), and increased insulin sensitivity. Endurance exercise significantly increased the activity of mitochondrial enzymes and the expression of GLUT4 protein, however, administration of Rhodiola sachalinensis did not affect them. The effect of exercise and/or Rhodiola sachalinensis administration on the expression of SNARE proteins was unclear. Our study suggested that improvement insulin sensitivity by exercise and/or Rhodiola sachalinensis administration in obese Zucker rats is independent of expression of SNARE proteins.
Subject(s)
Animals , Rats , Body Weight , Cell Membrane , Glucose Transporter Type 4 , Glucose , Insulin Resistance , Insulin , Muscle, Skeletal , Negotiating , Obesity , Oxidoreductases , Rats, Zucker , Rhodiola , Running , SNARE Proteins , Soluble N-Ethylmaleimide-Sensitive Factor Attachment Proteins , Vesicle-Associated Membrane Protein 2ABSTRACT
Objective To investigate the effect of insulin (INS) on nuclear factor-kappa B (NF-KB) activation in glomerular mesangial cells(GMC) of the Zucker rats,and the correlation between the activity of NF-kB induced by insulin to the ages and genotype of Zucker rats. Methods (1) Four groups of cultured GMCs(O3m,O10m,L3m and L10m) from the Zucker obese rats(3 months old and 10 months old) and Zucker lean rats(3 months old and 10 months old) were stimulated by insulin. (2) Electrophoretic mobility shift assay (EMSA) was used to detect the activity of NF-KB. Gel supershift assay was used to detect the subunit of NF-KB dimer. (3) The protein of NF-KB p65 in cytoplasm and cytoblast was analysed by Western Blot. Results (1) NF-KB activity in 4 groups GMCs was significantly higher than that in control group after induced of INS ( F=219. 65 P
ABSTRACT
It has been commonly noted that male patients have worse prognosis in adult polycystic kidney disease, IgA nephropathy, and membranous nephropathy. Several animal experiments were performed to clarify the mechanisms by which male gender confers a more adverse renal prognosis. Obese Zucker rats are characterized by severe obesity, insulin resistance, extremely high serum insulin level, high cholesterol level and spontaneous glomerular sclerosis. The aim of current study was to investigate whether there was a gender difference in 1) mean arterial pressure and renal function 2) glomerular volume by renal perfusion 3) glomerular hemodynamic factors including glomerular blood flow, glomerular pressure, renal vascular resistance, ultrafiltration coefficient by micropuncture techniques in obese male and female Zucker rats. There was no difference in blood glucose, serum insulin level, mean arterial pressure and glomerular sclerosis rate between male and female Zucker rats. Male Zucker rats had slightly higher glomerular filtration rate, kidney weight, single nephron glomerular filtration rate, glomerular capillary hydraulic pressure which was statistically insignificant. These findings suggest that gender difference in hemodynamic factors does not play a role in the progression of renal disease in obese Zucker rats.