TY - JOUR
T1 - Enhanced vasoactive intestinal peptide-induced prolactin secretion from anterior pituitary cells of incubating turkeys (Meleagris gallopavo)
AU - El Halawani, M. E.
AU - Silsby, J. L.
AU - Mauro, L. J.
N1 - Funding Information:
r Minnesota Agricultural Experiment Station Scientific Journal Article 17,633. Supported by USDA Grant 88-37242-3845.
Copyright:
Copyright 2014 Elsevier B.V., All rights reserved.
PY - 1990/10
Y1 - 1990/10
N2 - During incubation, female turkeys exhibit elevated circulating prolactin (PRL) which may be the result of enhanced pituitary responsiveness to vasoactive intestinal peptide (VIP). This hypothesis was tested by comparison of spontaneous and porcine VIP-induced PRL secretion from anterior pituitary cells of hens in various reproductive conditions. The effect of VIP and luteinizing hormone releasing hormone (LHRH), alone and in combination, on luteinizing hormone (LH) secretion was also examined. Incubation with pVIP (10-10 to 10-6 M) significantly stimulated PRL secretion at all incubation times tested (1-5 hr). This increase was greatest in cells from incubating hens, with those from laying, photorefractory, and quiescent (nonphotostimulated) hens secreting successively less PRL. These responses were obtained when spontaneous PRL secretions were compared. VIP induced approximately a similar 1.5-fold increase in LH secretion, in all reproductive groups. Also, VIP enhanced LHRH-induced LH secretion (1.2- to 1.6-fold; P < 0.0001). It is concluded that PRL secretion in vitro by pituitary cells from turkey hens in various reproductive stages reflects the circulating levels of PRL at these stages.
AB - During incubation, female turkeys exhibit elevated circulating prolactin (PRL) which may be the result of enhanced pituitary responsiveness to vasoactive intestinal peptide (VIP). This hypothesis was tested by comparison of spontaneous and porcine VIP-induced PRL secretion from anterior pituitary cells of hens in various reproductive conditions. The effect of VIP and luteinizing hormone releasing hormone (LHRH), alone and in combination, on luteinizing hormone (LH) secretion was also examined. Incubation with pVIP (10-10 to 10-6 M) significantly stimulated PRL secretion at all incubation times tested (1-5 hr). This increase was greatest in cells from incubating hens, with those from laying, photorefractory, and quiescent (nonphotostimulated) hens secreting successively less PRL. These responses were obtained when spontaneous PRL secretions were compared. VIP induced approximately a similar 1.5-fold increase in LH secretion, in all reproductive groups. Also, VIP enhanced LHRH-induced LH secretion (1.2- to 1.6-fold; P < 0.0001). It is concluded that PRL secretion in vitro by pituitary cells from turkey hens in various reproductive stages reflects the circulating levels of PRL at these stages.
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U2 - 10.1016/0016-6480(90)90157-H
DO - 10.1016/0016-6480(90)90157-H
M3 - Article
C2 - 2272474
AN - SCOPUS:0025001444
SN - 0016-6480
VL - 80
SP - 138
EP - 145
JO - General and Comparative Endocrinology
JF - General and Comparative Endocrinology
IS - 1
ER -
