Atrial natriuretic factor regulates steroidogenic responsiveness and cyclic nucleotide levels in mouse leydig cells [formula omitted

Abstract

The effects of synthetic atrial natriuretic factor (ANF) on the regulation of mouse Leydig cell steroidogenesis have been studied in vitro . ANF in nanomolar concentration increased testosterone production by more than 30-fold over basal levels. Concomitantly, cyclic guanosine monophosphate levels were increased 35-fold; cyclic adenosine monophosphate levels fell minimally (15–20%). ANF at low concentration (1×10 −11 M) inhibited testosterone production by luteinizing hormone-stimulated cells, while at higher concentration (> 2×10 −9M) ANF stimulated steroidogenesis beyond the level attained by luteinizing hormone alone. These results indicate that ANF can exert stimulatory effects on testosterone steroidogenesis in vitro , and that the mechanism may involve an intracellular messenger other than cyclic adenosine monophosphate.