Melanocyte Release Inhibiting Peptide (MRIP I) did not affect circulating levels of ACTH, LH, FSH, TSH, PRL, β MSH and insulin when iv infused (5.0 mg in 5 min plus 0.4 mg/min for 70-115 min), while it significantly reduced serum GH response to hypoglycemia in normal subjects and lowered serum GH levels in acromegalics. There was no correlation between the fall in serum GH after MRIP and after dopaminergic drugs in acromegaly. These data are compatible with either a direct suppressive action exerted by MRIP I at pituitary level or an extra pituitary effect not involving dopaminergic pathways. It can be speculated that since labelled MRIP I accumulates in the pineal and melatonin blunts GH response to hypoglycemia, the pineal gland might be involved in the MRIP I induced suppression of GH secretion.
|Number of pages||4|
|Journal||Journal of Clinical Endocrinology and Metabolism|
|Publication status||Published - 1976|
ASJC Scopus subject areas
- Endocrinology, Diabetes and Metabolism