title: Effect of oxytocin infusion on luteal blood flow and progesterone secretion in dairy cattle.
abstract: The objective of this study was to investigate the effects of oxytocin infusion on corpus luteum (CL) function during early to mid-diestrus by measuring luteal size (LS) and luteal blood flow (LBF) along with plasma levels of progesterone (P4) and prostaglandin metabolites (13,14-dihydro-15-keto-prostaglandin F(2α), PGFM). On day (D) 7 of the estrus cycle (D1 = ovulation), seven cows received 100 IU of oxytocin (OXY) or placebo (PL) following a Latin square design. LS and LBF increased in both groups over time and no differences were observed between the groups. PGFM did not differ either within the groups over time or between the groups at any time point. P4 of the OXY group was higher compared to that of the the PL group 360 min after the infusion (p = 0.01) and tended to be higher at the time points 450 min, 48 h, and 72 h (all p = 0.08). Results from this study support the hypothesis that OXY is not directly involved in the mechanism(s) governing blood flow of the CL and has no remarkable effects either on luteal size or P4 and PGFM plasma levels. Further investigation is needed to elucidate the role of OXY in CL blood flow during early and late luteal phases.
authors.affiliation: Clinic of Farm Animals, Faculty of Veterinary Medicine, Aristotle University of Thessaloniki, Thessaloniki 54627, Greece.
authors.forename: Christos N
authors.initials: CN
authors.lastname: Brozos
authors.forename: Metin S
authors.initials: MS
authors.lastname: Pancarci
authors.forename: Javier
authors.initials: J
authors.lastname: Valencia
authors.forename: Nikola
authors.initials: N
authors.lastname: Beindorff
authors.forename: Georgios
authors.initials: G
authors.lastname: Tsousis
authors.forename: Evaggelos
authors.initials: E
authors.lastname: Kiossis
authors.forename: Heinrich
authors.initials: H
authors.lastname: Bollwein
mesh_terms: D000818:Animals; D002417:Cattle / Q000502:physiology*; D003338:Corpus Luteum / Q000098:blood supply / Q000000981:diagnostic imaging / Q000187:drug effects* / Q000378:metabolism; D015237:Dinoprost / Q000031:analogs & derivatives / Q000097:blood; D030762:Estrous Cycle / Q000187:drug effects* / Q000502:physiology; D005260:Female; D007124:Immunoenzyme Techniques / Q000662:veterinary; D009929:Organ Size / Q000502:physiology; D010121:Oxytocin / Q000494:pharmacology*; D011374:Progesterone / Q000097:blood / Q000378:metabolism*; D011897:Random Allocation; D018615:Ultrasonography, Doppler, Color / Q000662:veterinary
chemical_list: C008228:15-keto-13,14-dihydroprostaglandin F2alpha; D011374:Progesterone; D010121:Oxytocin; D015237:Dinoprost