to evaluate the extent to which endogenous hormones in peripheral blood can account for uterine blood flow ( ubf ) , rates of blood flow and concentrations of estrone ( e1 ) , estradiol ( e2 ) , and progesterone ( p4 ) were measured simultaneously in four sheep during the estrous cycle and the first 3 wk of pregnancy .
C0042149
uterine
C0025329
estrous cycle