|
|
||||||||
AJP - Endocrinology and Metabolism, Vol 257, Issue 3 E439-E443, Copyright © 1989 by American Physiological Society
ARTICLES |
C. G. Ostenson, A. G. Cattaneo, J. C. Doxey and S. Efendic
Department of Endocrinology, Karolinska Hospital, Stockholm, Sweden.
The role of alpha-adrenoceptors in the regulation of glucose-induced insulin release (GIR) was investigated in islets of normal and neonatally streptozotocin-injected non-insulin-dependent diabetic rats (STZ). In normal islets GIR was suppressed to approximately 50% by 10(-8) M of the alpha 2-adrenergic agonist UK 14304, whereas 10(-9) M of the agonist induced a similar inhibition in STZ islets. In normal islets, suppression of GIR by UK 14304 (10(-8) M) was totally antagonized by 10(6) M idazoxan (alpha 2-antagonist) or 10(6) M phentolamine (alpha 1 + alpha 2-antagonist). In STZ islets, the inhibitory effect of UK 14304 (10(-9) M) was entirely reversed by 10(-5) M idazoxan or 10(-6) M phentolamine. The alpha 1-antagonist prazosin (10(-7)-10(-5) M) was without effect on insulin release suppressed by UK 14304 in normal and STZ islets. Insulin release at 3.3, 8.3, or 16.7 mM glucose was augmented by phentolamine but not by idazoxan. It is concluded that the inhibitory effect of catecholamines on insulin release is mediated by alpha 2-receptors in normal and STZ islets. Phentolamine augments basal and glucose-induced insulin release by a mechanism that does not involve alpha 2-adrenoceptors.
This article has been cited by other articles:
![]() |
S. Efendic, A. M. Efanov, P.-O. Berggren, and S. V. Zaitsev Two Generations of Insulinotropic Imidazoline Compounds Diabetes, December 1, 2002; 51(90003): S448 - 454. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. M. Efanov, S. V. Zaitsev, I. B. Efanova, S. Zhu, C.-G. Ostenson, and P.-O. Berggren Signaling and sites of interaction for RX-871024 and sulfonylurea in the stimulation of insulin release Am J Physiol Endocrinol Metab, April 1, 1998; 274(4): E751 - E757. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |