Stimulation of prolactin secretion from turkey anterior pituitary cells in culture.
Prolactin (PRL) secretion by monolayer cultures of turkey anterior pituitary cells was significantly increased (up to 44-fold) by vasoactive intestinal peptide (VIP), arginine vasotocin (AVT), and by an extract of turkey hypothalami (HE). Several other neuropeptides (including thyrotropin-releasing hormone) and neurotransmitters were ineffective in influencing PRL secretion at doses up to 10(-6) M. The dynamic PRL response to HE and VIP was studied using superfused pituitary cells attached to microcarrier beads. HE, administered in 30-min pulses, resulted in a significant, dose-related increase in PRL secretion from a basal secretion rate of 2.32 ng/min/10(7) cells to a peak secretion rate of 127.13 ng/min/10(7) cells at the highest dose of HE tested (1 mg tissue-equivalent weight/ml). VIP significantly increased PRL secretion at all doses studied (from 10(-10) to 10(-6) M), with 10(-8) M VIP producing a response similar to that observed with 1 mg/ml HE. A highly significant (P less than 0.001) linear relationship was demonstrated between the log-dose of VIP administered and peak PRL secretion rate. These studies suggest that VIP, but not TRH, may be a physiological stimulus for PRL release in the turkey.
Proudman
J A
JA
Avian Physiology Laboratory, USDA, Beltsville, Maryland 20705.
Opel
H
H
D000818:Animals; D002478:Cells, Cultured; D005260:Female; D007031:Hypothalamus / Q000502:physiology; D010903:Pituitary Gland, Anterior / Q000187:drug effects / Q000378:metabolism*; D011388:Prolactin / Q000378:metabolism*; D014020:Tissue Extracts / Q000494:pharmacology; D014422:Turkeys / Q000378:metabolism*; D014660:Vasoactive Intestinal Peptide / Q000494:pharmacology; D014668:Vasotocin / Q000494:pharmacology
D014020:Tissue Extracts; D014660:Vasoactive Intestinal Peptide; D011388:Prolactin; D014668:Vasotocin