Radioautographic localization of atrial natriuretic factor receptors in the rat testis

Recent data have suggested that atrial natriuretic factors (ANFs) can modulate Leydig cell functions. An in vitro radioautographic procedure on slide-mounted frozen testicular sections was used to localize ANF receptors in rat testis. The radioligand was rat [125I]ANF-28. It was demonstrated that ANF specific binding sites were present only in interstitial cells, and that the other testicular compartments were not significantly labeled. These results suggest that ANF could have some physiologic role in testicular functions.