STEROID BIOSYNTHESIS IN THE TESTIS OF DOGFISH (SQUALUS ACANTHIAS)

Abstract

SUMMARY Incubation of the testis of S. acanthias with [4- 14 C]progesterone led to the formation of labelled testosterone, 11-deoxycorticosterone, Reichstein's substance S, 20β-hydroxypregn-4-en-3-one, 20β,21-dihydroxypregn-4-en-3-one and 17α,20β,21-tri-hydroxypregn-4-en-3-one. Additional compounds obtained from other incubations were 3β-hydroxy-5β-pregnan-20-one and 17α,20β-dihydroxypregn-4-en-3-one. Each of these compounds was identified by chromatography and by formation of suitable derivatives. The formation of 21-hydroxylated steroids does not necessarily imply that 21-hydroxylation normally takes place in the testis tissue; it may merely reflect the presence of spermatozoa with their associated enzymes. There is slight evidence of seasonal variation in the steroid-modifying capacity of the dogfish testis.