Atrial natriuretic peptide precursor material in rat testis.

Atrial natriuretic peptide (ANP) has recently been suggested to play a role in the regulation of male reproduction. Specifically, it has been shown to affect steroidogenesis in Leydig cells. The data presented here demonstrate that the rat testis also contains immunoreactive, ANP-like material (IR-ANP). Characterization of this material was conducted by high-pressure liquid chromatography (HPLC) analysis employing two different antisera to recognize either the C- or the N-terminals of the ANP prohormone (ANP 1-126). The IR-ANP corresponded to the 15 kd ANP precursor molecule (ANP 1-126), indicating the synthesis of ANP within the testis. This was supported by the detection of ANP messenger RNA transcripts (Northern blot hybridization) in the testis. These data indicate that ANP is expressed in the rat testis and support the notion that it may function in a paracrine and/or autocrine fashion in this organ.