Ford S P, Chenault J R, Echternkamp S E
J Reprod Fertil. 1979 May;56(1):53-62. doi: 10.1530/jrf.0.0560053.
Blood flow to each uterine horn of cows during the oestrous cycle and early pregnancy was determined daily by use of electromagnetic blood flow probes placed around both middle uterine arteries. The pattern of blood flow to uteri of pregnant and non-pregnant cows was similar until Day 14 after mating or oestrus. Between Days 14 and 18 of pregnancy blood flow to the uterine horn containing the conceptus increased (P less than 0.01) 2- to 3-fold, whereas blood flow to the non-gravid uterine horn in these cows remained constant. No corresponding increase in blood flow to the uterine horn ipsilateral to the ovary bearing the CL was observed in non-pregnant cows during this 4-day period. By Day 19 of pregnancy, blood flow to the gravid uterine horn had returned to a level similar to that observed on Day 13. Blood flow to both uterine horns of pregnant cows remained constant from Days 19 to 25 and then increased to the gravid horn (P less than 0.01) markedly until Day 30 whereas blood flow to the non-gravid horn remained low. Uterine blood flow during the oestrous cycle of non-pregnant cows was positively correlated (P less than 0.01) with systemic concentrations of oestradiol and the ratio of oestradiol (pg/ml) to progesterone (ng/ml). There was no association between oestradiol concentrations and blood flow to the gravid uterine horn. These data indicate local control of uterine blood flow by the bovine conceptus which may function to create optimal conditions for the continuation of pregnancy.
在发情周期和妊娠早期，每天使用放置在子宫中动脉周围的电磁血流探头来测定奶牛每个子宫角的血流量。在配种或发情后第14天之前，怀孕和未怀孕奶牛子宫的血流模式相似。在妊娠第14天至18天期间，含有孕体的子宫角血流量增加（P<0.01）2至3倍，而这些奶牛非妊娠子宫角的血流量保持恒定。在此4天期间，未怀孕奶牛中与黄体所在卵巢同侧的子宫角血流量未观察到相应增加。到妊娠第19天，妊娠子宫角的血流量已恢复到第13天观察到的水平。怀孕奶牛两个子宫角的血流量在第19天至25天保持恒定，然后到第30天显著增加至妊娠子宫角（P<0.01），而非妊娠子宫角的血流量保持较低水平。未怀孕奶牛发情周期期间的子宫血流量与雌二醇的全身浓度以及雌二醇（pg/ml）与孕酮（ng/ml）的比值呈正相关（P<0.01）。雌二醇浓度与妊娠子宫角的血流量之间没有关联。这些数据表明牛的孕体对子宫血流量有局部控制作用，这可能有助于为妊娠的持续创造最佳条件。
