Increased PC-1 phosphodiesterase activity and inhibition of glucose uptake in adipocytes of type 2 diabetic rats
- 47 Downloads
This study was designed to understand the cellular mechanisms responsible for defects in the insulin-stimulated signal transduction pathway in a type 2 diabetic animal model. We examined the in vitro PC-1 phosphodiesterase activity and glucose uptake in adipose tissue of streptozotocin (STZ)-induced type 2 diabetic rats. The PC-1 activity was significantly increased in adipose tissue of diabetic rats (0.54 ± 0.08 nmol PNTP hydrolyzed/mg protein/min) compared with controls (0.29 ± 0.05 nmol PNTP hydrolyzed/mg protein/min, p < 0.05). Upon insulin stimulation (100 nM), glucose uptake in the adipose tissue of the controls (4.17 ± 1.28×10−8 μmol/mg/min) was significantly higher than that in the diabetic rats (1.26 ± 0.35×10−8; p < 0.05). These results suggest that elevated PC-1 phosphodiesterase activity and decreased glucose uptake in adipose tissues may be acquired characteristics contributing to the development of type 2 diabetes mellitus.
Key Wordsadipocytes glucose uptake PC-1 phosphodiesterase activity type 2 diabetes
Unable to display preview. Download preview PDF.
- 8.Friedman JE, Dohm GL, Leggett-Frazier N, Elton CW, Tapscott EB, Pories WJ, Caro JF: Restoration of insulin responsiveness in skeletal muscle of morbidly obese patients after weight loss: effect on muscle glucose transport and glucose transporter GLUT-4. J Clin Invest 89: 701–705, 1992PubMedGoogle Scholar
- 9.Virkamaka A, Ueki K, Khan CR: Protein-protein interaction in insulin signaling and the molecular mechanisms of insulin resistance. J Clin Invest 103: 931–943, 1999Google Scholar
- 10.McGrowder D, Ragoobirsingh D, Dasgupta T: Decreased insulin binding to mononuclear leucocytes and erythrocytes from dogs after S-nitroso-N-acetylpenicillamine administration. BMC Biochem 3: 1, 2002Google Scholar
- 12.World Health Organization (WHO): Definition, diagnosis and classification of diabetes mellitus Part 1: diagnosis and classification of diabetes mellitus. Department of non-communicable disease surveillance. Geneva: 1999Google Scholar
- 13.Marette A, Mauriege P, Marcotte B, Algie C, Bouchard C, Theriault G, Bukowiecki LJ, Marceau P, Biron S, Nadeau A, Despres JP: Regional variation in adipose tissue insulin action and GLUT4 glucose transporter expression in severely obesed premenopausal women. Diabetologia 40: 590–598, 1997PubMedCrossRefGoogle Scholar
- 20.Taylo SI: Insulin resistance or insulin deficiency: which is the primary cause of NIDDM? Diabetes 43: 735–740, 1994Google Scholar
- 26.Slot JW, Geuze HJ, Gigengack S, James DE, Lienhard GE.: Translocation of the glucose transporter GLUT4 in cardiac myocytes of the rat. Proc Natl Acad Sci USA 88: 7815–7819, 1991Google Scholar
- 29.Rothman DL, Schulman RG, Schulman GI: 31P nuclear magnetic resonance measurements of muscle glucose-6-phosphate: evidence for reduced insulin-dependent muscle glucose transport or phosphorylation activity in non-insulin-dependent diabetes mellitus. J Clin Invest 89: 1062–1075, 1992CrossRefGoogle Scholar