title: Resveratrol enhances insulin secretion by blocking K(ATP) and K(V) channels of beta cells.
abstract: The present study investigated the effect of resveratrol on the electrophysiology and insulin secretion of pancreatic beta cells, and examined resveratrol-induced alterations in insulin levels and plasma glucose of normal and streptozotocin-induced diabetic rats. Whole-cell voltage clamp study in the MIN6 cell, a mouse beta cell line, revealed that resveratrol significantly inhibited ATP-sensitive K(+) current at 3 micromol/l, and voltage-gated K(+) currents at 30 micromol/l. Ca(2+)-activated K(+) current was activated by resveratrol at 100 micromol/l. In MIN6 cells stained with membrane potential dye DiBAC(4)(5), resveratrol markedly depolarized membrane potential at the concentrations of 3-100 micromol/l. Insulin secretion was increased in the presence of resveratrol in MIN6, Hit-T15, and RIN-m5F cells. Resveratrol (3 mg/kg, i.p.) increased insulin secretion associated with a lowering in plasma glucose in normal rats, but not in streptozotocin-diabetic rats within the initial 60 min. In conclusion, resveratrol can act as an insulin-secretagogue through I(KATP) and I(KV) inhibition which can contribute to plasma glucose lowering effect in normal rats.
authors.affiliation: Institute of Pharmacology, National Taiwan University Medical College, Taipei, Taiwan.
authors.forename: Wen-Pin
authors.initials: WP
authors.lastname: Chen
authors.forename: Tzong-Cherng
authors.initials: TC
authors.lastname: Chi
authors.forename: Lee-Ming
authors.initials: LM
authors.lastname: Chuang
authors.forename: Ming-Jai
authors.initials: MJ
authors.lastname: Su
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D045744:Cell Line, Tumor; D006224:Cricetinae; D003921:Diabetes Mellitus, Experimental / Q000097:blood; D007328:Insulin / Q000097:blood / Q000378:metabolism*; D000078790:Insulin Secretion; D050417:Insulin-Secreting Cells / Q000187:drug effects* / Q000502:physiology; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects; D051379:Mice; D026902:Potassium Channel Blockers / Q000494:pharmacology*; D015221:Potassium Channels / Q000187:drug effects* / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D000077185:Resveratrol; D013267:Stilbenes / Q000494:pharmacology*
chemical_list: D001786:Blood Glucose; D007328:Insulin; D026902:Potassium Channel Blockers; D015221:Potassium Channels; D013267:Stilbenes; D000077185:Resveratrol