[Regulatory role of galanin on prolactin and beta-endorphin release from anterior pituitary lobe of rat].
The role of brain-gut peptide galanin in the regulation of prolactin (PRL) and beta-endorphin (beta-EP) release from anterior pituitary lobe was studied in vivo in conscious male rats and in vitro with cultured anterior pituitary cells of the rat. Galanin (1 microgram or 3 micrograms/rat) injected into the third cerebral ventricle of rats produced highly significant, dose-related increases of PRL resting secretion, but did not alter resting secretion of beta-EP and restraint stress-induced release of PRL and beta-EP. However, galanin (0.05, 0.5 and 1.0 micrograms/5 x 10(5) cells.ml-1) induced highly significant, dose-related increase of beta-EP secretion from dispersed anterior pituitary cells, but failed to alter significantly PRL secretion from the cultured cells. These results indicate that central galanin has a stimulatory role in pituitary PRL resting secretion via the hypothalamus, whereas peripheral galanin stimulates beta-EP secretion only via direct action of this peptide in anterior pituitary cells.
Xu
R K
RK
Department of Physiology, CAMS and PUMC, Beijing.
Zhou
Y Z
YZ
Huang
M Y
MY
Shan
H M
HM
Wang
Y
Y
Guo
C H
CH
Han
X S
XS
D000818:Animals; D002478:Cells, Cultured; D019004:Galanin; D007276:Injections, Intraventricular; D008297:Male; D009479:Neuropeptides / Q000494:pharmacology / Q000502:physiology*; D010455:Peptides / Q000494:pharmacology / Q000502:physiology*; D010903:Pituitary Gland, Anterior / Q000166:cytology / Q000378:metabolism*; D011388:Prolactin / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D001615:beta-Endorphin / Q000378:metabolism*
D009479:Neuropeptides; D010455:Peptides; D001615:beta-Endorphin; D019004:Galanin; D011388:Prolactin