Increased plasma VIP concentration in patients with prolactinoma.
Vasoactive intestinal polypeptide (VIP) is now considered to be a prolactin-releasing factor (PRF). The aim of this study was to determine the VIP concentration in peripheral blood in patients with prolactin-secreting adenoma compared to healthy subjects. We also examined the effect of bromocriptine administration on the plasma VIP concentration in patients with prolactinoma. Nine patients with prolactinoma (6 women and 3 men, aged 27-50) and 7 healthy control subjects (4 women and 3 men, aged 26-40) were examined. Blood samples for prolactin and VIP were collected at 06:00, 12:00, 18:00, 24:00. In prolactinoma blood was taken before and after bromocriptine administration. Serum prolactin concentration was determined by the radioimmunoassay. VIP concentration was measured by a specific radioimmunoassay Kit-INCSTAR Corp. (Minnesota, USA). Statistical significance was calculated using the analysis of variance. A single 5 mg oral dose of bromocriptine decreased the mean prolactin concentration during the first 24 hours of treatment. Plasma VIP concentration was higher in prolactinoma patients compared to healthy subjects. There was no change in plasma VIP level after bromocriptine administration.


CONCLUSIONS
in patients with prolactin secreting adenoma the plasma VIP concentration is increased.
Department of Endocrinology, Medical Centre for Postgraduate Education, Warsaw.
A
A
Makowska
W
W
Zgliczyński
J
J
Słowińska-Srzednicka
P
P
Soszyński
S
S
Zgliczyński
D000328:Adult; D000704:Analysis of Variance; D001971:Bromocriptine / Q000627:therapeutic use; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010911:Pituitary Neoplasms / Q000097:blood* / Q000188:drug therapy; D015175:Prolactinoma / Q000097:blood* / Q000188:drug therapy; D014660:Vasoactive Intestinal Peptide / Q000097:blood*
D014660:Vasoactive Intestinal Peptide; D001971:Bromocriptine