Ovarian and plasma prostaglandin E and F levels in brook trout (Salvelinus fontinalis) during pituitary-induced ovulation.

Prostaglandin E (PGE) and F (PGF) levels in plasma, ovarian tissue and coelomic fluid from ovulating brook trout (Salvelinus fontinalis) were measured using radioimmunoassays. The results demonstrate a significant increase in both plasma and ovarian PGF levels by the completion of ovulation (compared to gravid controls). Plasma PGF levels remained elevated 24 h following ovulation in females retaining ovulated eggs. Coelomic fluid from fish just completing ovulation contained PGF levels that were significantly higher than plasma PGF levels of corresponding fish. There were no significant variations in plasma PGE levels throughout ovulation; however, the ovarian PGE levels of gravid controls were significantly higher than those of fish just prior to, during or following ovulation.