Intrauterine infusion of highly enriched bovine trophoblast protein-1 complex exerts an antiluteolytic effect to extend corpus luteum lifespan in cyclic cattle.
Intrauterine infusion of enriched bovine trophoblast protein-1 complex (bTP-1) resulted in extension of interoestrous intervals and corpus luteum function in cyclic cattle. Conceptus proteins were obtained by culture of Day 17-18 conceptuses for 72 h. Media from the first (n = 28), second (n = 26) and third (n = 19) 24 h of conceptus incubations were utilized. A highly enriched preparation of bTP-1 was obtained by a combination of ammonium sulphate precipitation, ion-exchange chromatography, and h.p.l.c. gel filtration. Degree of purity of the final preparation was confirmed by gel electrophoresis and immunoblotting with antiserum to ovine trophoblast protein-1. Jersey cattle (3 per group) received intrauterine infusions, twice daily from Day 15.5 to 21.0, of bovine serum albumin, the entire array of bovine conceptus secretory proteins (bCSP) from the 3 days of conceptus culture, or bTP-1. Infusions were via a catheter into the uterine horn ipsilateral to the corpus luteum. Oestrous cycle length in bTP-1-treated cows (26.1 +/- 1.3 days) was greater than for cows given BSA (19.5 +/- 1.3 days) or bCSP (21.5 +/- 1.3 days). Similarly, progesterone concentrations in serum remained elevated for a longer period of time for bTP-1-treated cows than for cows treated with BSA or bCSP. Residual variance associated with vena cava concentrations of PGF-2 alpha at Days 19-21 after oestrus (which included the variance between 15-min periods within cows) was reduced in cows treated with bTP-1 as compared to other groups. Lack of a bCSP effect may have been due to low amounts of bTP-1 in conceptus-conditioned medium from cultures of greater than 24 h. None the less, purified bTP-1 was effective in extending luteal function and appears to be the antiluteolytic agent of early pregnancy.
Helmer
S D
SD
Department of Dairy University of Florida, Gainesville 32611-0701.
Hansen
P J
PJ
Thatcher
W W
WW
Johnson
J W
JW
Bazer
F W
FW
D000818:Animals; D001345:Autoradiography; D002417:Cattle; D015180:Electrophoresis, Gel, Two-Dimensional; D004971:Estrus / Q000187:drug effects*; D005260:Female; D007370:Interferon Type I; D008186:Luteolytic Agents / Q000037:antagonists & inhibitors*; D011257:Pregnancy Proteins / Q000008:administration & dosage / Q000302:isolation & purification / Q000494:pharmacology*; D011374:Progesterone / Q000097:blood; D011460:Prostaglandins F / Q000097:blood; D014599:Uterus
D007370:Interferon Type I; D008186:Luteolytic Agents; D011257:Pregnancy Proteins; D011460:Prostaglandins F; C020947:interferon tau; D011374:Progesterone