Effects of Growth Hormone Release‐inhibiting Hormone and Bromocryptine (Cb 154) in States of Abnormal Pituitary‐adrenal Function

Abstract

Growth hormone release-inhibiting hormone (GHR-IH) was administered to five patients with abnormal pituitary-adrenal function. There was immediate suppression by about 50% of ACTH levels in two patients who had undergone bilateral adrenalectomy because of Cushing's disease; one of them had Nelson's syndrome. Bromocryptine (2-5 mg) suppressed ACTH levels by 62-67% for more than 6 h in these patients. GHR-IH did not significantly influence cortisol secretion by an adrenal carcinoma and only slight changes were seen in two patients with Addison's disease. The possible therapeutic implications are discussed.

Direct effects of thyrotropin-releasing hormone, cyproheptadine, and dopamine on adrenocorticotropin secretion from human corticotroph adenoma cells in vitro.

“…Thus, it may be plausible to ascribe the effect of bromocriptine, a specific dopamine receptor agonist with a prolonged action, to a direct inhibition of ACTH release from corticotroph adenoma cells in these patients. Compared with the previous reports on the efficacy of bromocriptine in patients with Cushing's disease (9)(10)(11)(12)(13)(14)(15), the percentage of responders in the present study ( (1 ,uM) (Fig. 7).…”

“…Subsequent studies confirmed the efficacy of this drug in the management of some, though not all, patients with Cushing's disease and Nelson's syndrome (2)(3)(4)(5)(6)(7)(8). Bromocriptine, a dopaminergic agonist, likewise has been shown to lower plasma ACTH levels in some patients, and its clinical use is currently being evaluated (9)(10)(11)(12)(13)(14)(15). These works opened the possibility of medical management of the disorder.…”

“…In addition to cyproheptadine, the therapeutic action of bromocriptine in Cushing's disease has been evaluated in recent years (9)(10)(11)(12)(13)(14)(15). A marked diminution of plasma ACTH after a single oral dose of bromocriptine has been observed in some patients with the disease as well as in subjects with Nelson's syndrome (9)(10)(11)(12)15), although other workers failed to demonstrate such an effect (13,14). In the present study, 0.1 ,uM dopamine inhibited the release of ACTH in all of the five adenoma cells studied.…”

Somatostatin Analogue(SMS 201-995) Decreases Plasma Levels of Corticotropin(ACTH) and Corticotropin-Releasing Hormone in a Patient with Ectopic ACTH-Producing Tumors.

“…It has been reported that the increased secretion of ACTH from the pituitary is able to be inhibited by the administration of SRIF or its long-acting analogue in Nelson's syndrome (Tyrrell et al, 1975, Benker et al, 1976, Lamberts et al, 1989, Reichlin, 1983. However, it was uncertain whether SRIF inhibits secretion of CRH or not.…”

“…(SRIF) or long-acting SRIF analogue has been reported to be effective in suppressing the secretion of pituitary hormones, such as growth hormone (GH) in patients with acromegaly (Yen et al, 1974, Plewe et al, 1984, Kelijman et al, 1988, thyrotropin (TSH) in patients with TSH-secreting pituitary tumors (Comi et al, 1987, WemeauTet al, 1988 and corticotropin (ACTH) in patients with Nelson's syndrome (Tyrell et al, 1975, Benker et al, 1976, Lamberts et al, 1989 or with ectopic ACTH secretion (Bertagna et al, 1989). However, it is not certain whether the agent is effective in inhibiting the release of hypothalamic releasing factors, such as GH-releasing hormone (GH-RH), TSH-releasing hormone (TRH) and ACTHreleasing hormone (CRH) (Lamberts, 1988).…”