APPLICATION OF HPLC METHODS TO IDENTIFY PLASMA PROFILES OF 11-OXYGENATED ANDROGENS AND OTHER STEROIDS IN ARCTIC CHARR (SALVELINUS-ALPINUS) DURING GONADAL RECRUDESCENCE

The plasma profiles of free and conjugated steroid hormones of Arctic charr (Salvelinus alpinus) sampled at four stages in the annual reprod uctive cycle of females and at two stages in the reproductive cycle of males were studied using a solid-phase extraction technique in combin ation with a reverse-phase HPLC separation technique. Androstenedione (A(4)), testosterone (T), 11 beta-hydroxyandrostenedione (11 beta OHA) and 11-ketoandrostenedione (11KA) were the major androgens present at all stages of gonadal development in both males and females. In addit ion, in males, 11 ketotestosterone (11KT) was present in spermiating c harr, and 11 beta-hydroxytestosterone (11 beta OHT) was present in bot h immature and spermiating animals. 17 beta-Hydroxyprogesterone (17 be ta OHP) was present as a small peak in immature, vitellogenic and post -ovulatory females, as well as in spermiating males; a larger peak was found in pre-ovulatory females. Further, 17,20 beta-dihydroxy-4-pregn en-3 one was found in pre-ovulatory females and in both groups of male s. Cortisol and cortisone were found in most samples analysed, and 11- deoxycortisol was evident as a small peak in all four groups of female s. Low levels of glucuronidated T, 17 beta OHT, 17 beta OHP, and 11KT were also present in some plasma samples; no significant levels of sul phated steroids were found. (C) 1997 Elsevier Science Inc.