Growth hormone induces resistance to the mitogenic action of insulin through local IGF-I. Studies in normal and Pygmy T-cell lines.
Growth hormone (GH) and insulin have both mitogenic and metabolic actions. The growth-promoting effects of GH in vivo are thought to be mediated by insulin-like growth factor-I (IGF-I), whereas the metabolic effects of GH are thought to be either direct or mediated by factors other than IGF-I. In previous studies using HTLV-II-transformed T-lymphoblast cell lines established from normal individuals, we have shown that GH preincubation induces resistance to the growth-promoting (mitogenic) action of insulin. In this study, using T-cell lines from 3 American control subjects, 1 African control subject, and 1 African Pygmy (the latter previously shown to be resistant to the growth-promoting actions of both IGF-I and GH), we examined the role of local IGF-I in the mediation of GH-induced resistance to the mitogenic action of insulin. In these studies, we quantified the stimulation of T-cell colony formation in response to insulin in the presence and absence of either GH or IGF-I.(ABSTRACT TRUNCATED AT 250 WORDS)
Geffner
M E
ME
Department of Pediatrics, University of California, Los Angeles.
Bersch
N
N
Bailey
R C
RC
Golde
D W
DW
D000328:Adult; D000349:Africa / Q000208:ethnology; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D044383:Black People; D002460:Cell Line; D002461:Cell Line, Transformed; D004305:Dose-Response Relationship, Drug; D005006:Ethnicity; D013006:Growth Hormone / Q000494:pharmacology*; D015367:Human T-lymphotropic virus 2 / Q000276:immunology; D006801:Humans; D007074:Immunoglobulin G / Q000494:pharmacology; D007328:Insulin / Q000494:pharmacology*; D007333:Insulin Resistance / Q000276:immunology*; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology*; D007700:Kinetics; D008213:Lymphocyte Activation; D008297:Male; D017526:Receptor, IGF Type 1 / Q000276:immunology / Q000502:physiology*; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism
D000911:Antibodies, Monoclonal; D007074:Immunoglobulin G; D007328:Insulin; D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone; D017526:Receptor, IGF Type 1