Role of vasoactive intestinal polypeptide (VIP) in regulating the pituitary function in man.
Intramuscular injection of synthetic VIP (200 micrograms) resulted in a rapid increase in plasma prolactin (PRL) concentrations in normal women, which was accompanied by the 4- to 7-fold increase in plasma VIP levels. Mean (+/- SE) peak values of plasma PRL obtained 15 min after the injection of VIP were higher than those of saline control (28.1 +/- 6.7 ng/ml vs. 11.4 +/- 1.6 ng/ml, p less than 0.05). Plasma growth hormone (GH) and cortisol levels were not affected by VIP in normal subjects. VIP injection raised plasma PRL levels (greater than 120% of the basal value) in all of 5 patients with prolactinoma. In 3 of 8 acromegalic patients, plasma GH was increased (greater than 150% of the basal value) by VIP injection. In the in vitro experiments, VIP (10(-8), 10(-7) and 10(-6) M) stimulated PRL release in a dose-related manner from the superfused pituitary adenoma cells obtained from two patients with prolactinoma. VIP-induced GH release from the superfused pituitary adenoma cells was also shown in 5 out of 6 acromegalic patients. VIP concentrations in the CSF were increased in most patients with hyperprolactinemia and a few cases with acromegaly. These findings indicate that VIP may play a role in regulating PRL secretion in man and may affect GH secretion from pituitary adenoma in acromegaly.
D000236:Adenoma / Q000378:metabolism / Q000503:physiopathology*; D003994:Bucladesine / Q000494:pharmacology; D005260:Female; D007987:Gonadotropin-Releasing Hormone / Q000494:pharmacology; D013006:Growth Hormone / Q000097:blood; D006801:Humans; D007700:Kinetics; D008297:Male; D010911:Pituitary Neoplasms / Q000378:metabolism / Q000503:physiopathology*; D011388:Prolactin / Q000097:blood / Q000378:metabolism*; D013973:Thyrotropin-Releasing Hormone; D014660:Vasoactive Intestinal Peptide / Q000097:blood / Q000134:cerebrospinal fluid
D007987:Gonadotropin-Releasing Hormone; D014660:Vasoactive Intestinal Peptide; D013973:Thyrotropin-Releasing Hormone; D003994:Bucladesine; D011388:Prolactin; D013006:Growth Hormone