Effect of oxytocin on plasma concentrations of 13,14-dihydro-15-keto-prostaglandin F2 alpha during the oestrous cycle and early pregnancy in the goat.
The effect of subcutaneous oxytocin on plasma concentrations of 13,14-dihydro-15-keto-prostaglandin (PG) F2 alpha (PGFM) was examined in the goat at various periods during the oestrous cycle and early pregnancy. 100 i.u. oxytocin was administered daily for 4 day, the dose being divided and given at 0900 and 2100 h; PGFM concentrations were assessed after the first treatment of each day. On days 3-6 (oestrus, day 0) PGFM concentrations increased significantly (P less than 0.001) within 15 minutes and both non-pregnant and mated goats exhibited oestrus behaviour by day 7. Significant (P less than 0.01) increases in PGFM were also produced on days 7-10, in both non-pregnant and pregnant goats, but the responses diminished from day 7 to day 10; only one goat (non-pregnant) came into oestrus. There was a marked difference in response between groups, however, during days 12-15. In non-pregnant goats significant (P less than 0.05) increases in PGFM were detected on days 13-15, but in pregnant animals oxytocin was without effect. Similarly, oxytocin did not increase PGFM concentrations on days 17-20 of pregnancy. However, uterine responsiveness reappeared in pregnant goats with significant (P less than 0.01) increases in PGFM on days 24 and 25.
Cooke
R G
RG
Department of Veterinary Preclinical Sciences University of Liverpool Veterinary Field Station Leahurst, South Wirral, Cheshire.
Payne
J H
JH
Homeida
A M
AM
D000818:Animals; D015237:Dinoprost / Q000031:analogs & derivatives* / Q000097:blood; D004971:Estrus / Q000502:physiology; D005260:Female; D006041:Goats / Q000502:physiology*; D010121:Oxytocin / Q000494:pharmacology*; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000502:physiology*
C008228:15-keto-13,14-dihydroprostaglandin F2alpha; D010121:Oxytocin; D015237:Dinoprost