Evidence for a direct effect of captopril on early steps of insulin action in BC3H-1 myocytes.
Captopril, an angiotensin-converting enzyme (ACE) inhibitor, has been reported to improve insulin sensitivity. However, despite extensive investigation, the mechanisms responsible for this effect are not fully understood. Reduction of plasma angiotensin II and inhibition of kininase II have been suggested to contribute to improve insulin sensitivity. Insulin binding was measured at tracer insulin concentration in intact cells with or without captopril treatment. Specific binding, expressed as percent of total insulin added, was not different in control and captopril-treated cells. However, captopril treatment caused an increase in insulin-induced insulin receptor substrate-1 (IRS-1) phosphorylation accompanied by an increased association of IRS-1 with phosphoinositide-3 kinase (PI-3 kinase), despite no change on insulin receptor (IR) autophosphorylation. There was also an increased threonine kinase B (AKT) phosphorylation in captopril-treated cells followed by enhanced basal and insulin-stimulated glucose uptake. These results indicate that captopril treatment has a direct effect on early phosphorylation events induced by insulin in BC3H-1 myocytes.
Moisés
Regina S
RS
Disciplina de Endocrinologia, Universidade Federal de São Paulo, Escola Paulista de Medicina, São Paulo, Brazil.
Carvalho
Carla R O
CR
Shiota
Debora
D
Saad
Mario J A
MJ
D000806:Angiotensin-Converting Enzyme Inhibitors / Q000494:pharmacology; D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D002216:Captopril / Q000494:pharmacology*; D002460:Cell Line; D003847:Deoxyglucose / Q000378:metabolism; D005947:Glucose / Q000378:metabolism; D007328:Insulin / Q000378:metabolism / Q000494:pharmacology*; D055504:Insulin Receptor Substrate Proteins; D047908:Intracellular Signaling Peptides and Proteins; D051379:Mice; D008809:Mice, Inbred C3H; D009132:Muscles / Q000187:drug effects* / Q000378:metabolism; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D010750:Phosphoproteins / Q000378:metabolism; D010766:Phosphorylation; D019000:Phosphotyrosine / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt; D011972:Receptor, Insulin / Q000378:metabolism
D000806:Angiotensin-Converting Enzyme Inhibitors; D002216:Captopril; D003847:Deoxyglucose; D005947:Glucose; D007328:Insulin; D055504:Insulin Receptor Substrate Proteins; D047908:Intracellular Signaling Peptides and Proteins; D019869:Phosphatidylinositol 3-Kinases; D010750:Phosphoproteins; D019000:Phosphotyrosine; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins; D051057:Proto-Oncogene Proteins c-akt; D011972:Receptor, Insulin; C526295:Irs1 protein, mouse; C526298:Irs2 protein, mouse