ISSN:
1432-0428
Keywords:
Isolated islets
;
guinea-pig
;
prostaglandin synthesis
;
glucagon secretion
;
arginine
;
noradrenaline
;
indomethacin
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary Previous studies have demonstrated that prostaglandins stimulate glucagon secretionin vitro andin vivo. The present work was aimed at investigating the influence of two inhibitors of prostaglandin synthesis, isopropyl-2 nicotinoyl-3 indole (L8027) and indomethacin, on basal and arginine- or noradrenaline-stimulated glucagon release from isolated guinea-pig islets incubated in the absence of glucose. L8027 (10−4 and 10−5 mol/l) did not alter basal glucagon release, blocked almost completely the glucagon response to arginine (10−2 mol/l), had no effect on the glucagon release induced by noradrenaline (10−4H mol/l), but reduced the stimulatory effect of a lower concentration of noradrenaline (5.10−7 mol/l). The kinetic study of this inhibitory effect demonstrated that (1) it necessitates preincubation of the islets with L8027 for 30 minutes before the addition of arginine, (2) after a short preincubation period (30 minutes) in the presence of L8027, removal of the inhibitor at the time of arginine stimulation resulted in enhanced glucagon response, (3) on the contrary, after a prolonged incubation period (75 min) with arginine and L8027, the inhibitory effect remained transiently detectable after removal of L8027. Indomethacin similarly blocked arginine- and noradrenaline-induced glucagon secretion. These results suggest that an intra-insular synthesis of prostaglandins is involved in the A cell response to arginine and noradrenaline.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01219651
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