The effect of glucose upon the release of glucagon and insulin from the perfused rat pancreas in vitro was studied by varying both the concentration of glucose (from 3.3 to 4.6, 8.5, or 11.1 mmol/l) and the time of exposure to an elevated concentration of the sugar (5, 10 or 23 min). The results sug
Time-dependent inhibition of insulin release: glucose-arginine interactions in the perfused rat pancreas
โ Scribed by R. Nesher; L. Waldman; E. Cerasi
- Publisher
- Springer
- Year
- 1984
- Tongue
- English
- Weight
- 372 KB
- Volume
- 26
- Category
- Article
- ISSN
- 0012-186X
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โฆ Synopsis
The isolated perfused rat pancreas was stimulated sequentially with arginine or glucose to analyze the time-dependent modulation of insulin release. A 10-min perfusion with arginine (5.0 mmol/l) induced 75% inhibition of the insulin response to repeated arginine stimulation 10 min later. When glucose (8.3 mmol/l) was given as two pulses, inhibition of the second insulin response was less pronounced. The inhibitory effect generated by arginine also suppressed the insulin response to glucose (27.7 mmol/l), and this inhibitory effect persisted for over 80 min. Stimulation for 30 min with glucose (27.7 mmol/l) strongly potentiated the insulin responses to a pair of arginine stimuli given 20 min later. However, despite augmented secretion rates, the insulin response to the second arginine pulse was still inhibited by 75%. When insulin secretion was strongly amplified by two 10 min pulses of the synergistic mixture of arginine (5.0 mmol/l) and glucose (8.3 mmol/l), there was no inhibition of the second insulin response. If glucose (8.3 mmol/l) was present during the first arginine stimulation only, the response to the second arginine pulse was inhibited as in control experiments. However, when glucose was added to the second arginine pulse only, the inhibition generated by the first arginine pulse did not express itself, insulin release remaining similar to control.(ABSTRACT TRUNCATED AT 250 WORDS)
๐ SIMILAR VOLUMES
Brief stimulation of the pancreas with arginine causes a refractory state which reduces the insulin response to subsequent stimulations (time-dependent inhibition). In control subjects, a pair of arginine injections (75 mg/kg) at a 30-min interval resulted in 20% reduction of peak and integrated ins