Insulin hypoglycaemia and cholinergic blockade: response of plasma immunoreactive beta-endorphin.
Six normal subjects were studied to investigate the mechanisms involved in the release of immunoreactive beta-endorphin (ir-beta EP) in response to insulin hypoglycaemia. Insulin alone (0.2 U/kg body weight) was followed after a 30 min lag period by a congruent to 2.5 fold elevation of plasma ir-beta EP, with a return to basal levels by 90 min. Concurrent infusion of 10% dextrose at 250 ml/h for 2 h prevented the increase in plasma ir-beta EP levels, suggesting an effect of hypoglycaemia rather than a direct effect of insulin. Premedication with atropine 0.6 mg at -30 min was followed by hypoglycaemia equivalent to that seen with insulin alone, but no increase in plasma ir-beta EP, suggesting the involvement of cholinergic mechanisms in the neural mediation of ir-beta EP release in response to hypoglycaemia.
D000328:Adult; D001285:Atropine / Q000494:pharmacology*; D001786:Blood Glucose / Q000032:analysis; D004723:Endorphins / Q000097:blood*; D005260:Female; D006801:Humans; D007328:Insulin / Q000494:pharmacology*; D008297:Male; D011863:Radioimmunoassay; D001615:beta-Endorphin
D001786:Blood Glucose; D004723:Endorphins; D007328:Insulin; D001615:beta-Endorphin; D001285:Atropine