title: Effect of S-adenosylhomocysteine on insulin-independent release of pyruvate dehydrogenase activator from rat adipocyte plasma membranes.
abstract: The addition of insulin to adipocyte plasma membranes has been shown to release a low molecular weight, acid stable mediator which activates mitochondrial pyruvate dehydrogenase. The insulin-dependent release of this activator is dependent on the method used to prepare the plasma membranes. Adipocyte plasma membranes prepared in 0.25 M sucrose, 10 mM MOPS, pH 7.4 released an activator of pyruvate dehydrogenase in an insulin-independent manner. Insulin is required to stimulate phospholipid methylation in these membranes. The inhibition of insulin-stimulated phospholipid methylation with 1 mM S-adenosylhomocysteine resulted in a significant increase in amount and/or activity of the pyruvate dehydrogenase activator. The insulin-dependent dependent release of mediators of insulin action from adipocyte plasma may be regulated by phospholipid methylation.
mesh_terms: D000273:Adipose Tissue / Q000187:drug effects* / Q000502:physiology; D000818:Animals; D002462:Cell Membrane / Q000187:drug effects / Q000502:physiology; D006710:Homocysteine / Q000031:analogs & derivatives*; D066298:In Vitro Techniques; D007328:Insulin / Q000494:pharmacology*; D008297:Male; D008745:Methylation; D010743:Phospholipids / Q000378:metabolism; D011768:Pyruvate Dehydrogenase Complex / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D012435:S-Adenosylhomocysteine / Q000494:pharmacology*
chemical_list: D007328:Insulin; D010743:Phospholipids; D011768:Pyruvate Dehydrogenase Complex; C029131:pyruvate dehydrogenase activator; D006710:Homocysteine; D012435:S-Adenosylhomocysteine