Inhibition of insulin release induced by galanin in the dog is not exclusively mediated by activation of ATP-sensitive K+ channels.
Exogenous galanin (9 pmol/min during 20 min i.a.) decreased insulin levels in the plasma sampled from the pancreatic vein of the blood-perfused pancreas of dogs in which ganglionic transmission and beta-adrenoceptors had been blocked. This effect was not modified by idazoxan (1 mg/kg followed by 0.02 mg/kg/min i.v.) but was partially reduced (50%) by glibenclamide (1 mg/kg followed by 0.02 mg/kg/min i.v.). This dose of glibenclamide blocked entirely the hypoinsulinemic activity of diazoxide, an activator of pancreatic ATP-modulated K+ channels, whereas the dose of idazoxan prevented the effect of the alpha 2-adrenoceptor agonist UK-14,304. Therefore, in dogs, the decrease in insulin secretion produced by exogenous galanin is only partially mediated by activation of glibenclamide-sensitive ATP-gated K+ channels and is independent of alpha 2-adrenoceptor stimulation.
Lorrain
J
J
Synthélabo Recherche (L.E.R.S.) Bagneux, France.
Angel
I
I
Eon
M T
MT
Oblin
A
A
Langer
S Z
SZ
D000255:Adenosine Triphosphate / Q000502:physiology*; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology*; D000818:Animals; D000068438:Brimonidine Tartrate; D003981:Diazoxide / Q000494:pharmacology; D004146:Dioxanes / Q000494:pharmacology; D004285:Dogs; D005260:Female; D019004:Galanin; D005728:Ganglia, Sympathetic / Q000187:drug effects*; D005905:Glyburide / Q000494:pharmacology; D019329:Idazoxan; D007328:Insulin / Q000097:blood / Q000378:metabolism*; D000078790:Insulin Secretion; D008297:Male; D009638:Norepinephrine / Q000097:blood; D010179:Pancreas / Q000187:drug effects* / Q000378:metabolism; D010455:Peptides / Q000494:pharmacology*; D015221:Potassium Channels / Q000187:drug effects*; D011810:Quinoxalines / Q000494:pharmacology; D011942:Receptors, Adrenergic, alpha / Q000187:drug effects; D012680:Sensitivity and Specificity
D000319:Adrenergic beta-Antagonists; D004146:Dioxanes; D007328:Insulin; D010455:Peptides; D015221:Potassium Channels; D011810:Quinoxalines; D011942:Receptors, Adrenergic, alpha; D000068438:Brimonidine Tartrate; D019004:Galanin; D000255:Adenosine Triphosphate; D003981:Diazoxide; D005905:Glyburide; D009638:Norepinephrine; D019329:Idazoxan