Androgen metabolites in bovine follicular fluid.
The values of C21-steroids, Delta4-androgens, estrogens as well as 5alpha-reduced steroids have been determined in follicular fluid obtained from superovulated and untreated cows. In the three cows treated with a hormone regimen to induce superovulation, the levels of progesterone and estradiol determined in 3 to 6 follicles per cow ranged from 65 to 448 ng/ml and 1.9 to 8.6 ng/ml, respectively while the concentrations of androstenedione and testosterone varied between 1.5 to 2.5 ng/ml. Low levels of dihydrotestosterone and androstane-3alpha, 17beta-diol (approximately 30 to 50% of Delta4-androgens) were found in the bovine follicular fluid. In untreated cows, the follicular steroid concentrations were divided into two groups on the basis of the ratio between estrogen and Delta4-androgen concentrations. In estrogen-rich follicles, the ratio of estrogens Delta4- androgens was higher than 1 and in estrogen-poor follicle, the ratio of estrogens Delta4- androgens was lower than 1. Pregnenolone, dehydroepiandrosterone, androst-5-ene-3beta, 17beta-diol, progesterone, androstenedione and testosterone levels were not significantly different in the two groups while the levels of estradiol and estrone were approximately 100-fold higher in the estrogen-rich group. The concentrations of 5alpha-reduced steroids particularly, dihydrotestosterone, androstane-3alpha, 17beta-diol and androsterone as well as their glucuronides which were found at values extremely low (under 1 ng/ml) were not significantly different in both groups. The results indicate that low levels of 5alpha-reduced steroids and their glucuronides are present in bovine follicular fluid and their concentrations remained fairly stable either in estrogen-rich or estrogen-poor groups.
Prévost
J
J
MRC Group in Molecular Endocrinology Le Centre Hospitalier de l'Université Laval, 2705 Blvd. Laurier, Ste-Foy, Québec, G1V 4G2, Canada.
Bélanger
A
A
Bernard
C
C
Lambert
R D
RD