Luteinizing hormone secretion following intracerebroventricular administration of morphine in the prepuberal gilt.
Antagonism of endogenous opioids with naloxone stimulates luteinizing hormone (LH) release in mature but not prepuberal gilts. The present report demonstrates that the opiate agonist morphine (500 micrograms), administered intracerebroventricularly (ICV), reduced LH secretion in both ovariectomized mature and prepuberal gilts. We suggest that opioid receptors are functionally coupled to the GnRH secretory system in prepuberal gilts even though endogenous opioid peptide modulation of LH secretion was not demonstrable in our previous studies.
Barb
C R
CR
USDA-ARS, Richard B. Russell Agricultural Research Center, Athens, GA 30613.
Kineman
R D
RD
Kesner
J S
JS
Rampacek
G B
GB
Kraeling
R R
RR
D000818:Animals; D001921:Brain / Q000187:drug effects; D005260:Female; D007276:Injections, Intraventricular / Q000662:veterinary; D007986:Luteinizing Hormone / Q000097:blood / Q000378:metabolism*; D009020:Morphine / Q000008:administration & dosage / Q000494:pharmacology*; D010052:Ovariectomy / Q000662:veterinary; D012741:Sexual Maturation; D013552:Swine / Q000378:metabolism* / Q000502:physiology
D009020:Morphine; D007986:Luteinizing Hormone