Application of HPLC methods to identify plasma profiles of 11-oxygenated androgens and other steroids in arctic charr ( Salvelinus alpinus) during gonadal recrudescence

Abstract

The plasma profiles of free and conjugated steroid hormones of Arctic charr ( Salvelinus alpinus) sampled at four stages in the annual reproductive cycle of females and at two stages in the reproductive cycle of males were studied using a solid-phase extraction technique in combination with a reverse-phase HPLC separation technique. Androstenedione (A 4), testosterone (T), 11β-hydroxyandrostenedione (11 βOHA) and 11-ketoandrostenedione (11KA) were the major androgens present at all stages of gonadal development in both males and females. In addition, in males, 11 ketotestosterone (11KT) was present in spermiating charr, and 11 β-hydroxytestosterone (11βOHT) was present in both immature and spermiating animals. 17β-Hydroxyprogesterone 17βOHP) 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, 17,20β-dihydroxy-4-pregnen-3-one was found in pre-ovulatory females and in both groups of males. Cortisol and cortisone were found in most samples analysed, and 11-deoxycortisol was evident as a small peak in all four groups of females. Low levels of glucuronidated T, 17βOHT, 17βOHP, and 11KT were also present in some plasma samples; no significant levels of sulphated steroids were found.