The Presence of Atrial Natriuretic Peptide (ANP) in Spermatozoa of Bufo arenarum, and Effects of GnRH

Atrial natriuretic peptide (ANP)-like immunoreactivity has been demonstrated in the testes of adult Bufo arenarum. Reaction was limited to the head of mature spermatozoa attached to Sertoli cells, interstitial tissue, and seminiferous tubules walls. An immuohistochemical study of isolated spermatozoa showed the reaction to be limited to the basal area of spermatozoon head. After spermiation induced by GnRH, testicular spermatozoa were not immunoreactive. Neither isolated spermatozoa from homogenized testes nor isolated spermatozoa from urine immunostained. The demonstration of immunoreactive ANP in B. arenarum testes, its specific location in specific regions of spermatozoa, and the absence of immunostaining after GnRH treatment, suggest that the "cardiac" peptide may be involved in testicular function.