Summary
The effect of cooling to 27° C was studied in islets of Langerhans exposed to 5 and 50 mM potassium in the absence of glucose. Membrane potential and insulin release were measured simultaneously from microdissected mouse islets while 45Ca outflow and insulin release were measured from collagenase-isolated rat islets. Cooling inhibited potassium-induced insulin release in both preparations. However, calcium entry estimated from electrical records and from 45Ca outflow experiments was only slightly affected by decreasing the temperature to 27° C. It is concluded that the inhibition of insulin release caused by cooling to 27° C can, within limits, be dissociated from calium influx.
Key-Words
Insulin Release
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Islets of Langerhans
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Calcium Entry
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Temperature Effects
