Mode of action of chlorpromazine (CPZ) blockage on 13,14-dihydroprostaglandin F2-alpha formation in rat ovary.
The mode of action of the inhibitory effect of CPZ on 13,14-dihydroprostaglandin F2-alpha (13,14H2-PGF2-alpha) formation in rat ovary was examined. The inhibition of 13,14H2-PGF2-alpha formation and of ovulation induced by a proestrus were completely recovered by an injection of hCG (25 IU/rat) or LH-RH (500 ng/rat) at 15:00 on the same day. 13,14H2-PGF2-alpha formation and ovulation were not inhibited by a single injection of prolactin (PRL:6 IU/rat) at 13:00 on the day of proestrus. Repeated injection of PRL inhibited cyclic ovulation and 13,14H2-PGF2-alpha formation. The estrus cycle of PRL treated animals showed a continuous state of diestrus. Although 13,14H2-PGF2-alpha formation and ovulation were inhibited by the repeated injection of CPZ, the repeated-simultaneous injection of CPZ and bromocriptine at 10:00 once a day for 3 days from the first day of diestrus partly restored both and entirely reversed the suppression of the cyclic-changes in the in the vaginal smear pattern. These results indicate that the inhibition of 13,14H2-PGF2-alpha formation induced by a single injection of CPZ probably occurs via the suppression of LH-RH release from the hypothalamus, whereas PRL secretion may participate in the inhibitory effects of repeated injections of CPZ.
Department of Pharmacology and Toxicology, Tokyo College of Pharmacy, Japan.
H
H
Kogo
H
H
Iida
K
K
Taya
S
S
Sasamoto
N
N
Inazu
T
T
Satoh
D000818:Animals; D001971:Bromocriptine / Q000494:pharmacology; D002746:Chlorpromazine / Q000494:pharmacology*; D003864:Depression, Chemical; D015237:Dinoprost / Q000031:analogs & derivatives*; D005260:Female; D010053:Ovary / Q000187:drug effects / Q000378:metabolism*; D010060:Ovulation / Q000187:drug effects; D011388:Prolactin / Q000494:pharmacology; D011460:Prostaglandins F / Q000096:biosynthesis*; D051381:Rats; D011919:Rats, Inbred Strains
D011460:Prostaglandins F; C026527:13,14-dihydroprostaglandin F2alpha; D001971:Bromocriptine; D011388:Prolactin; D015237:Dinoprost; D002746:Chlorpromazine