Submitted to: Federation of American Societies for Experimental Biology Conference
Publication Type: Abstract Only
Publication Acceptance Date: 2/9/1996
Publication Date: N/A
Technical Abstract: A study was conducted to measure placental 11B-HSD, which catalyzes the reversible conversion of cortisol to cortisone, and to correlate 11B-HSD with fetal size and sex. 11B-HSD dehydrogenase (11-DH; cortisol to cortisone) and oxoreductase (11-OR; cortisone to cortisol) activities were measured in placentae for 22 fetuses from 3 pregnant gilts at day 75 of gestation (term = 114 days). Tritiated cortisol or cortisone (0.3 uCi; 4.5 pmol) was incubated with triplicate 80-mg placental samples in Minimum Essential Medium at 37 C for 90 min. 11-DH (275 +/- 18 fmol/90 min/100 ug protein) was almost fourfold greater than 11-OR (56 +/- 4). Placental 11-OR was greater (P = 0.04) when associated with female (61 +/- 6) than with male (50 +/- 4) fetuses. Placental 11-DH was comparable (P = 0.40) for female (315 +/- 24) and male (226 +/- 23) fetuses. The ratio of 11-DH:11-OR was greater (P = 0.04) for female (6.3 +/- 0.5) than male (5.1 +/- 0.6) fetuses. 11-OR was negatively correlated with fetal weight and length for female fetuses (r = -0.43; P < 0.01) whereas 11-DH was positively correlated with fetal length for male fetuses (r = 0.63; P < 0.01). Hence at 75 days of porcine gestation, placental 11-DH predominates, associations between 11B-HSD activity and fetal size exist, and a sexual dimorphism is present for 11-DH and 11-OR.