Effects of UK-14,304, noradrenaline, and propranolol on insulin release from transplanted mouse islets

Abstract

Shi C-L, Sehlin J, Täljedal, I-B. Effects of UK-14,304, noradrenaline, and propranolol on insulin release from transplanted mouse islets. Eur J Endocrinol 1996;135:724–8. ISSN 0804-4643 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 μmol/l, completely inhibited glucose-stimulated insulin release from untransplanted islets but not from grafts, whether or not the β adrenergic blocker, L-propranolol, was present. UK-14,304, an α2-specific adrenergic agonist, inhibited glucose-induced insulin secretion from untransplanted islets by 80–92% at 0.1 or 1 μmol/l, and by 35–56% at 5–10 nmol/l, Insulin secretion from islet grafts was also markedly inhibited by 0.1 or 1 μmol/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 α2 adrenoceptors on the β-cells. Chun-Liang Shi, Department of Histology and Cell Biology, Umeå University, S-901 87 Umeå, Sweden