A vanadyl sulfate-bovine serum albumin complex stimulates the release of lipoprotein lipase activity from isolated rat fat pads through an increase in the cellular content of cAMP and myo-inositol 1,4,5-trisphosphate.
A vanadyl sulfate-bovine serum albumin complex (vanadyl-BSA) prolonged the stability of the V4+ oxidation state, although vanadyl alone can readily change the oxidation state from V4+ to V5+ under physiological conditions. Vanadyl-BSA stimulated the release of lipoprotein lipase (LPL) activity from isolated rat fat pads and increased the cellular LPL activity in a time-dependent manner. These effects were independent of protein synthesis. Propranolol, quin 2-AM, ruthenium red, and neomycin all inhibited LPL release more potently than the increase in activity. In contrast, potent inhibition of the increase effect was observed with genistein and wortmannin. Short-term incubation of the fat pads with vanadyl-BSA showed a transient increase in the cellular content of cAMP and myo-inositol 1,4,5-trisphosphate (IP3), which was inhibited by propranolol and neomycin, respectively. These results suggest that vanadyl-BSA stimulates the release of LPL activity through an increase in the cellular content of cAMP and IP3, leading to an increased intracellular Ca2+ concentration, and that it also increases cellular LPL activity via process(es) sensitive to genistein and wortmannin.
Motoyashiki
T
T
Department of Biochemistry, Faculty of Pharmacy and Pharmaceutical Sciences, Fukuyama University, Hiroshima, Japan.
Miyake
M
M
Yoshida
A
A
Morita
T
T
Ueki
H
H
D000273:Adipose Tissue / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D000730:Androstadienes / Q000494:pharmacology; D000818:Animals; D000242:Cyclic AMP / Q000378:metabolism*; D003513:Cycloheximide / Q000494:pharmacology; D004789:Enzyme Activation; D019833:Genistein / Q000494:pharmacology; D015544:Inositol 1,4,5-Trisphosphate / Q000378:metabolism*; D008071:Lipoprotein Lipase / Q000378:metabolism*; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D012710:Serum Albumin, Bovine / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000494:pharmacology*; D017968:Vanadium Compounds / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000494:pharmacology*; D000077191:Wortmannin
D000730:Androstadienes; D017968:Vanadium Compounds; D012710:Serum Albumin, Bovine; C034028:vanadyl sulfate; D015544:Inositol 1,4,5-Trisphosphate; D003513:Cycloheximide; D019833:Genistein; D000242:Cyclic AMP; D008071:Lipoprotein Lipase; D000077191:Wortmannin