Publication Abstract

Identification of free and conjugated sex steroids and cortisol in the milt of Pacific herring, Clupea harengus pallasi

A.P. Scott, N. Sherwood, A.V.M. Canario and C. Warby

Milt from Pacific herring (Clupea harengus pallasi) was extracted and purified on reversed-phase high-performance liquid chromatography. The fractions were radioimmunoassayed for free and conjugated steroids. Fractions containing significant amounts of immunoreactive material were subjected to further purification on thin-layer chromatography. Substantial amounts of cortisol (271 ng/g of milt) and 17 alpha, 20 beta -dihydroxy-4-pregnen-3-one (ca. 38 ng/g of milt) were found in the free fractions of one of the extracts. Substantial amounts of cortisol (229 ng/g of milt), 17alpha, 20beta -dihydroxy-4-pregnen-3-one (25.7 ng/g of milt), and 3alpha,17alpha ,21-trihydroxy-5 beta -pregnan-20-one (13 ng/g of milt) were found in the conjugated fractions of both extracts. Levels of other steroids (free and conjugated) ranged from undetectable (< 0.1) to 5.9 ng/g of milt. The possible reasons for the differences in free steroid levels between the extracts, and the potential role of the steroids as pheromones, are discussed.

Reference:

A.P. Scott, N. Sherwood, A.V.M. Canario and C. Warby, 1991. Identification of free and conjugated sex steroids and cortisol in the milt of Pacific herring, Clupea harengus pallasi. Canadian Journal of Zoology, 69: 104-110.