purified porcine relaxin ( 3000 u/mg ) was administered im ( rlx-im ; 1 mg ; n = 2 ) and in the cervical os ( rlx-os ; 1 mg ; n = 2 ) on day 273 ( approximately 10 days before parturition normally occurs ) of gestation to determine the profiles of immunoreactive relaxin and its effects on progesterone , estrone ( e1 ) , and 17 beta-estradiol ( 17 beta-e2 ) secretion in peripheral blood plasma of beef heifers .
C0032961
gestation
C0033308
progesterone