Hypothalmic-pituitary adrenal responsiveness to dexamethasone-insulin tolerance test in acromegalic patients before and during treatment with bromocriptine.
Insulin tolerance tests were carried out in 10 acromegalic patients after 1 mg dexamethasone had been given the previous evening (DEX-ITT). Nine patients showed a rise in plasma 11-OHCS and four patients showed a rise in plasma growth hormone (GH) levels. These responses were unaltered after treatment with bromocriptine 10 mg daily for two months. Basal plasma GH levels fell in 6 of the patients and the mean plasma GH levels of the 10 patients during an oral glucose tolerance test (OGTT) fell from 63.2 +/- 25.5 ng/ml before treatment to 53.0 +/- 27.1 ng/ml (mean +/- sem; p less than 0.05). These data fail to confirm a previous report of abnormal hypothalmic-pituitary-adrenal suppressibility during a DEX-ITT in acromegalic patients. They also indicate that bromcriptine does not alter the responses of plasma 11-OHCS and plasma GH to the DEX-ITT despite lowering plasma GH levels.
D015062:11-Hydroxycorticosteroids / Q000097:blood; D000172:Acromegaly / Q000188:drug therapy* / Q000503:physiopathology; D000328:Adult; D000368:Aged; D001786:Blood Glucose / Q000032:analysis; D001971:Bromocriptine / Q000627:therapeutic use*; D003907:Dexamethasone; D005260:Female; D005951:Glucose Tolerance Test; D013006:Growth Hormone / Q000097:blood; D006801:Humans; D007030:Hypothalamo-Hypophyseal System / Q000503:physiopathology*; D007328:Insulin; D008297:Male; D008875:Middle Aged; D010913:Pituitary-Adrenal System / Q000503:physiopathology*
D015062:11-Hydroxycorticosteroids; D001786:Blood Glucose; D007328:Insulin; D001971:Bromocriptine; D003907:Dexamethasone; D013006:Growth Hormone