Diminished inhibitory effect of noradrenaline on insulin release from mouse islets transplanted to kidney.
Insulin release is inhibited by adrenergic alpha-2 agonism in normal beta-cells. To test whether the inhibitory response to noradrenaline is modified by transplantation, we studied insulin release from freshly isolated islets and from syngeneic islets transplanted under the kidney capsule of non-diabetic C57BL/6 mice. When perifused in vitro, fresh islets, as well as grafts harvested 1 or 3 weeks after transplantation, reacted to 2.5 mumol/l noradrenaline with a complete inhibition of insulin release induced by 16.7 mmol/l D-glucose. In contrast, islet grafts harvested after 6, 12, or 21 weeks exhibited a conspicuous insulin secretory response to 16.7 mmol/l glucose in the presence of 2.5 mumol/l noradrenaline. Also a concentration of 0.25 mumol/l, noradrenaline inhibited the glucose-induced insulin release from fresh islets but not from 6-week-old islet grafts. It is concluded that transplantation under the kidney capsule induces a decreased inhibitory responsiveness to noradrenaline in islet grafts.
Shi
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CL
Department of Histology and Cell Biology, Umeå University, Sweden.
Täljedal
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IB
D058669:Adrenergic alpha-2 Receptor Antagonists; D000316:Adrenergic alpha-Agonists / Q000494:pharmacology*; D000818:Animals; D006085:Graft Survival; D066298:In Vitro Techniques; D007328:Insulin / Q000378:metabolism*; D007329:Insulin Antagonists / Q000494:pharmacology*; D000078790:Insulin Secretion; D007515:Islets of Langerhans / Q000187:drug effects / Q000378:metabolism*; D016381:Islets of Langerhans Transplantation / Q000502:physiology*; D007668:Kidney; D007700:Kinetics; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009638:Norepinephrine / Q000494:pharmacology*; D011336:Probability; D013997:Time Factors; D016042:Transplantation, Heterotopic
D058669:Adrenergic alpha-2 Receptor Antagonists; D000316:Adrenergic alpha-Agonists; D007328:Insulin; D007329:Insulin Antagonists; D009638:Norepinephrine