endometrial concentrations of prostaglandins f2 alpha ( pgf2 alpha ) and e2 ( pge2 ) were measured by specific radioimmunoassay in sheep , on day 14 of estrous cycle or pregnancy , during luteolysis ( day 16 of the cycle ) , and after implantation ( day 23 of pregnancy ) : concentrations observed on day 14 of cycle and pregnancy were similar .
C0012472
pge2
C0032961
pregnancy