Prostaglandins may participate in opioidergic and cholinergic control of the diurnal changes of tuberoinfundibular dopaminergic neuronal activity and serum prolactin level in ovariectomized, estrogen-treated rats.
The roles of prostaglandins (PGs) involved in opioidergic, cholinergic, and serotonergic regulation of the diurnal changes of tuberoinfundibular dopaminergic (TIDA) neuronal activities were investigated in ovariectomized, estrogen-treated rats. Treatment with naloxone [10 mg/kg, intraperitoneal (i.p.)], atropine (5 mg/kg, i.p.), or ketanserin (10 mg/kg, i.p.) at either 1200 or 1400 h prevented the afternoon decrease of TIDA neuronal activity and the prolactin (PRL) surge. Intracerebroventricular (i.c.v.) injection of PGE(1) (5 microg/3 microl/rat) at 1500 h significantly reversed the effects of naloxone and atropine, but not that of ketanserin. In ovariectomized, estrogen-primed rats pretreated with indomethacin, i.c.v. injection of either nicotine (10 ng/rat) or fentanyl (10 ng/rat) failed to suppress the TIDA neuronal activity and to stimulate the PRL secretion. These data suggest that PG may be involved in opioidergic and cholinergic control of the diurnal changes of TIDA neuronal activity and the PRL secretion in ovariectomized (OVX) + E(2) rats.
Chu
Y C
YC
Department of Clinical Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan.
Tsou
M Y
MY
Pan
J T
JT
D000109:Acetylcholine / Q000378:metabolism*; D000701:Analgesics, Opioid / Q000494:pharmacology; D000818:Animals; D002940:Circadian Rhythm / Q000187:drug effects / Q000502:physiology*; D004298:Dopamine / Q000378:metabolism*; D004967:Estrogens / Q000378:metabolism / Q000494:pharmacology; D005260:Female; D007030:Hypothalamo-Hypophyseal System / Q000187:drug effects / Q000378:metabolism; D007650:Ketanserin / Q000494:pharmacology; D008473:Median Eminence / Q000187:drug effects / Q000378:metabolism*; D018727:Muscarinic Antagonists / Q000494:pharmacology; D009270:Naloxone / Q000494:pharmacology; D009292:Narcotic Antagonists / Q000494:pharmacology; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*; D018847:Opioid Peptides / Q000378:metabolism*; D010052:Ovariectomy; D011388:Prolactin / Q000097:blood* / Q000378:metabolism; D011453:Prostaglandins / Q000378:metabolism* / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012701:Serotonin / Q000378:metabolism
D000701:Analgesics, Opioid; D004967:Estrogens; D018727:Muscarinic Antagonists; D009292:Narcotic Antagonists; D018847:Opioid Peptides; D011453:Prostaglandins; D012701:Serotonin; D009270:Naloxone; D011388:Prolactin; D007650:Ketanserin; D000109:Acetylcholine; D004298:Dopamine