Effects of UK-14,304, noradrenaline, and propranolol on insulin release from transplanted mouse islets.
To elucidate the adrenergic responsiveness of transplanted pancreatic islets, normal BALB/c mice received 150 syngeneic islets under the left kidney capsule. After 12-40 weeks, the grafts were removed and compared with untransplanted islets by an in vitro perifusion technique. Noradrenaline (NA), 3 mumol/l, completely inhibited glucose-stimulated insulin release from untransplanted islets but not from grafts, whether or not the beta adrenergic blocker, L-propranolol, was present. UK-14,304, an alpha 2-specific adrenergic agonist, inhibited glucose-induced insulin secretion from untransplanted islets by 80-92% at 0.1 or 1 mumol/l, and by 35-56% at 5-10 nmol/l. Insulin secretion from islet grafts was also markedly inhibited by 0.1 or 1 mumol/l, but not by 5 or 10 nmol/l, UK-14,304. It is suggested that the diminished adrenergic inhibition of insulin release from islet grafts reflects an altered function of the alpha 2 adrenoceptors on the beta-cells.
Shi
C L
CL
Department of Histology and Cell Biology, Umeå University, Sweden.
Sehlin
J
J
Täljedal
I B
IB
D000322:Adrenergic Agonists / Q000494:pharmacology*; D000316:Adrenergic alpha-Agonists / Q000494:pharmacology; D000318:Adrenergic beta-Agonists / Q000494:pharmacology; D000818:Animals; D000068438:Brimonidine Tartrate; D005260:Female; D005947:Glucose / Q000494:pharmacology*; D066298:In Vitro Techniques; D007328:Insulin / Q000378:metabolism*; D000078790:Insulin Secretion; D007515:Islets of Langerhans / Q000187:drug effects / Q000378:metabolism*; D016381:Islets of Langerhans Transplantation / Q000502:physiology*; D051379:Mice; D008807:Mice, Inbred BALB C; D009638:Norepinephrine / Q000494:pharmacology; D010477:Perfusion; D011433:Propranolol / Q000494:pharmacology; D011810:Quinoxalines / Q000494:pharmacology; D013997:Time Factors
D000322:Adrenergic Agonists; D000316:Adrenergic alpha-Agonists; D000318:Adrenergic beta-Agonists; D007328:Insulin; D011810:Quinoxalines; D000068438:Brimonidine Tartrate; D011433:Propranolol; D005947:Glucose; D009638:Norepinephrine