Alteration of oestrous cycle length, ovarian function and oxytocin-induced release of prostaglandin F-2 alpha by intrauterine and intramuscular administration of recombinant bovine interferon-alpha to cows.
An experiment was conducted to (i) determine whether administration of recombinant bovine interferon-alpha I1 (rBoIFN-alpha) attenuates oxytocin-induced release of prostaglandin F-2 alpha and (ii) confirm previous observations that rBoIFN-alpha causes acute changes in body temperature and circulating concentrations of progesterone. Cows were treated twice a day from Day 14 to Day 17 after oestrus with a control regimen (bovine serum albumin (BSA), i.m. + BSA intrauterine (i.u.)), rBoIFN-alpha, i.u. + BSA, i.m. (rBoIFN-IU) or rBoIFN-alpha, i.m. + BSA, i.u. (rBoIFN-IM). On Day 17, plasma concentrations of 13,14-dihydro,15-keto-prostaglandin F-2 alpha (PGFM) were measured after injection of oxytocin. Cows treated with rBoIFN-IU and rBoIFN-IM had longer oestrous cycles and luteal lifespans than control cows. A hyperthermic response and decline in plasma concentrations of progesterone was noticed after administration of rBoIFN-alpha on Day 14. On other days, the hyperthermic response was not present and the decline in progesterone was less pronounced. There was no significant effect of rBoIFN-alpha on circulating concentrations of oestradiol between Days 14 and 17. The release of PGFM induced by oxytocin was lower in cows treated with rBoIFN-alpha than in control cows. Oxytocin caused increased plasma concentrations of PGFM in four of five control cows, two of five rBoIFN-IU cows and two of five rBoIFN-IM cows. The peak PGF-2 alpha response to oxytocin (peak value after injection minus mean concentration before injection) was 257.8 +/- 61.3 pg/ml for control cows, 100.7 +/- 40.8 pg/ml for rBoIFN-IU and 124.9 +/- 40.4 pg/ml for rBoIFN-IM. It is concluded that rBoIFN-alpha can reduce oxytocin-induced PGFM release and may therefore extend the lifespan of the corpus luteum by interfering with events leading to luteolytic release of PGF from the uterus. Administration of rBoIFN-alpha can cause acute changes in body temperature and circulating concentrations of progesterone that become less severe after repeated exposure to rBoIFN-alpha.
Plante
C
C
Dairy Science Department, University of Florida, Gainesville 32611-0701.
Thatcher
W W
WW
Hansen
P J
PJ
D000818:Animals; D001831:Body Temperature / Q000187:drug effects; D002417:Cattle; D015237:Dinoprost / Q000031:analogs & derivatives / Q000096:biosynthesis* / Q000097:blood; D004971:Estrus / Q000187:drug effects*; D005260:Female; D007273:Injections, Intramuscular; D007370:Interferon Type I / Q000494:pharmacology*; D006080:Ovarian Follicle / Q000187:drug effects; D010053:Ovary / Q000187:drug effects* / Q000378:metabolism; D010121:Oxytocin / Q000494:pharmacology*; D011374:Progesterone / Q000097:blood; D011863:Radioimmunoassay; D011994:Recombinant Proteins
D007370:Interferon Type I; D011994:Recombinant Proteins; C008228:15-keto-13,14-dihydroprostaglandin F2alpha; D011374:Progesterone; D010121:Oxytocin; D015237:Dinoprost