Effects of bovine somatotropin on uterine genes related to the prostaglandin cascade in lactating dairy cows.
Multiparous Holstein cows, averaging 80 d in milk, were used to examine the effect of exogenous bovine somatotropin (bST) on uterine expression of estrogen receptor alpha (ERalpha), prostaglandin endoperoxide synthase-2 (PGHS-2), and peroxisome proliferator-activated receptor delta (PPARdelta). About 12 h before expected ovulation in a synchronization protocol, cows were assigned to receive bST (500 mg, n = 11) or serve as untreated controls (n = 10). Cows that ovulated (n = 9 bST, 8 control) were divided within treatment to be killed on d 3 or 7 postovulation. Samples of intercaruncular endometrial tissue from uterine horns ipsilateral to the corpus luteum were collected and stored at -80 degrees C for subsequent mRNA analyses. Endometrial concentrations of ERalpha and PGHS-2 mRNA transcripts were greater on d 7 than on d 3 of the estrous cycle, but did not differ between treatments. Compared with untreated cows, short-term bST treatment decreased PGHS-2 protein expression at d 7 of the estrous cycle. Concentration of PPARdelta mRNA transcript in the uterus decreased between d 3 and 7 of the estrous cycle and was negatively correlated with ERalpha and PGHS-2 mRNA concentrations. Short-term administration of bST to lactating dairy cows had minimal effects on uterine genes encoding ERalpha, PGHS-2, and PPARdelta at d 3 and 7 of the estrous cycle but there may be an inverse relationship between PPARdelta and uterine expression of ERalpha and PGHS-2 genes.
Balaguer
S A
SA
Department of Animal Sciences, University of Florida, Gainesville 32611, USA.
Pershing
R A
RA
Rodriguez-Sallaberry
C
C
Thatcher
W W
WW
Badinga
L
L
D000818:Animals; D015152:Blotting, Northern; D015153:Blotting, Western; D002417:Cattle; D051546:Cyclooxygenase 2; D047628:Estrogen Receptor alpha / Q000235:genetics; D030762:Estrous Cycle; D005260:Female; D015870:Gene Expression / Q000187:drug effects*; D013006:Growth Hormone / Q000494:pharmacology*; D007774:Lactation; D047494:PPAR delta / Q000235:genetics; D011451:Prostaglandin-Endoperoxide Synthases / Q000235:genetics; D011453:Prostaglandins / Q000378:metabolism*; D012333:RNA, Messenger / Q000032:analysis; D014599:Uterus / Q000737:chemistry*
D047628:Estrogen Receptor alpha; D047494:PPAR delta; D011453:Prostaglandins; D012333:RNA, Messenger; C073294:growth hormone, bovine; D013006:Growth Hormone; D051546:Cyclooxygenase 2; D011451:Prostaglandin-Endoperoxide Synthases