Increased PC-1 phosphodiesterase activity and inhibition of glucose uptake in adipocytes of type 2 diabetic rats.
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 x 10(-8) micromol/mg/min) was significantly higher than that in the diabetic rats (1.26 +/- 0.35 x 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.
Barrett
Karlene
K
Department of Basic Medical Sciences (Biochemistry Section), University of the West Indies, Mona Campus, Kingston 7, Jamaica, West Indies.
McGrowder
Donovan
D
Brown
Paul
P
Ragoobirsingh
Dalip
D
D000273:Adipose Tissue / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D000818:Animals; D003921:Diabetes Mellitus, Experimental / Q000201:enzymology / Q000378:metabolism*; D003924:Diabetes Mellitus, Type 2 / Q000201:enzymology / Q000378:metabolism*; D005260:Female; D005947:Glucose / Q000378:metabolism*; D007328:Insulin / Q000378:metabolism; D008297:Male; D010727:Phosphoric Diester Hydrolases / Q000378:metabolism*; D011755:Pyrophosphatases / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction; D013997:Time Factors
D007328:Insulin; D010727:Phosphoric Diester Hydrolases; C065962:ectonucleotide pyrophosphatase phosphodiesterase 1; D011755:Pyrophosphatases; D005947:Glucose