Effect of flunixin meglumine on endogenous prostaglandin F2 alpha secretion during cloprostenol-induced abortion in mares.
OBJECTIVE
To determine the relative role of endogenous prostaglandin F2 alpha (PGF2 alpha) secretion in cloprostenol-induced abortion in mares that no longer require luteal progesterone secretion for maintenance of pregnancy, and to evaluate the ability of a prostaglandin cyclooxygenase inhibitor (flunixin meglumine) to prevent cloprostenol-induced abortion.


METHODS
The effect of flunixin meglumine on PGF2 alpha secretion and outcome of pregnancy was compared between mares treated with cloprostenol only and mares treated with cloprostenol plus flunixin meglumine.


METHODS
Five pregnant mares, aged 4 to 15 years, of light-horse type.


METHODS
Cloprostenol (250 micrograms) was administered at 24-hour intervals to 5 pregnant mares. Flunixin meglumine (500 mg, IV) was administered at 8-hour intervals starting 15 minutes before the first cloprostenol administration. Hourly blood samples were analyzed for 15-ketodihydro-PGF2 alpha, progesterone, and estrogen concentrations. Previously reported data on cloprostenol-induced abortion in 6 pregnant mares treated daily with cloprostenol only were used as historic controls.


RESULTS
The mean (+/- SEM) interval from first cloprostenol administration to fetal expulsion 56.4 (+/- 13.7) hours and number of cloprostenol administrations 3.2 (+/- 0.6) in the 5 flunixin meglumine-treated mares were not significantly different, compared with values for 6 pregnant mares treated daily with cloprostenol only, 48.6 (+/- 5.6) hours and 2.8 (+/- 0.2) cloprostenol administrations. Flunixin meglumine did not inhibit endogenous PGF2 alpha secretion. Prostaglandin F2 alpha secretion rates on the day before and day of fetal expulsion were similar in both groups.


CONCLUSIONS
Flunixin meglumine at a dosage of 500 mg/animal, administered IV every 8 hours, is ineffective in modulating uterine PGF2 alpha secretion during cloprostenol-induced abortion.


CONCLUSIONS
Flunixin meglumine is ineffective in the modulation of prostaglandin-induced uterine PGF2 alpha secretion and, therefore, does not offer a viable alternative for the prevention of abortion in mares at risk of abortion because of systemic illness.
Daels
P F
PF
Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA.
Mohammed
H O
HO
Odensvik
K
K
Kindahl
H
H
D000028:Abortion, Induced / Q000662:veterinary*; D000818:Animals; D003002:Clonixin / Q000031:analogs & derivatives* / Q000494:pharmacology; D003008:Cloprostenol; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology*; D015237:Dinoprost / Q000037:antagonists & inhibitors / Q000378:metabolism* / Q000502:physiology; D004967:Estrogens / Q000097:blood / Q000378:metabolism; D005260:Female; D006736:Horses / Q000378:metabolism*; D011247:Pregnancy; D011256:Pregnancy Outcome / Q000662:veterinary; D011374:Progesterone / Q000097:blood / Q000378:metabolism; D013997:Time Factors
D016861:Cyclooxygenase Inhibitors; D004967:Estrogens; D003008:Cloprostenol; D011374:Progesterone; C014558:flunixin meglumine; D015237:Dinoprost; D003002:Clonixin