Inhibition of L-dopa induced growth hormone release in normal and diabetic subjects by glucose administration.
Administration of L-dopa 1 g induced an increase of plasma growth hormone (GH) levels in seven of ten healthy volunteers and in six of ten hyperglycemic insulin-dependent diabetic subjects; the maximal GH response was higher in normal subjects. Addition of 100 g glucose orally to the L-dopa completely abolished the GH response of both groups. The difference between the effect of endogenous hyperglycemia and the effect of a sudden increase of blood sugar after glucose administration on L-dopa induced GH release in diabetic subjects may be explain by the resetting of the hypothalamic control for pituitary GH release to higher levels of blood glucose.
D000328:Adult; D003920:Diabetes Mellitus / Q000503:physiopathology*; D005260:Female; D005947:Glucose; D013006:Growth Hormone / Q000378:metabolism*; D006801:Humans; D006943:Hyperglycemia / Q000503:physiopathology; D007980:Levodopa / Q000037:antagonists & inhibitors; D008297:Male; D008875:Middle Aged
D007980:Levodopa; D013006:Growth Hormone; D005947:Glucose