title: Testosterone rapidly stimulates insulin release from isolated pancreatic islets through a non-genomic dependent mechanism.
abstract: The action of testosterone on the 45Ca2+ uptake and insulin secretion was studied in short-term experiments using isolated pancreatic islets of Langerhans. Testosterone (1 microM) stimulated 45Ca2+ uptake within 60 seconds of incubation on similar proportion than tolbutamide. Also, the hormone rapidly increased insulin release (34%; 180 seconds) on the presence of non-stimulatory concentrations of glucose (3 mM). Impermeant testosterone-BSA significantly stimulated the secretion of insulin to a lower percentage (10%). The action of the hormone is specific--neither 17beta-E2 nor progesterone stimulated insulin secretion in the presence of 3 mM glucose. The action of testosterone on insulin secretion was dose-dependent, and at rat plasma physiological concentrations (25 nM), stimulus was 17% (p < 0.05). In conclusion, in isolated pancreatic islets experiments, physiological concentration of testosterone rapidly stimulate insulin secretion and 45Ca2+ uptake through a membrane bound mechanism.
authors.affiliation: Departamento de Fisiologia, ICBS, UFRGS, Porto Alegre, Brazil.
authors.forename: M L
authors.initials: ML
authors.lastname: Grillo
authors.forename: A P
authors.initials: AP
authors.lastname: Jacobus
authors.forename: R
authors.initials: R
authors.lastname: Scalco
authors.forename: F
authors.initials: F
authors.lastname: Amaral
authors.forename: D O
authors.initials: DO
authors.lastname: Rodrigues
authors.forename: E S
authors.initials: ES
authors.lastname: Loss
authors.forename: G F
authors.initials: GF
authors.lastname: Wassermann
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D007328:Insulin / Q000378:metabolism*; D000078790:Insulin Secretion; D007515:Islets of Langerhans / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D013739:Testosterone / Q000494:pharmacology*
chemical_list: D007328:Insulin; D013739:Testosterone; D002118:Calcium