NITRIC-OXIDE SYNTHASE-CONTAINING NERVES AND GANGLIA IN THE DOG PROSTATE - A COMPARISON WITH OTHER TRANSMITTERS

The distribution of nitric oxide synthase immunoreactive nerves in the dog prostate was compared to the total innervation (as estimated by p rotein gene product 9.5 immunoreactivity), and to that of adrenergic ( tyrosine hydroxylase-immunoreactive), cholinergic (acetylcholinesteras e-positive), and some peptidergic nerves immunoreactive towards vasoac tive intestinal peptide, pituitary adenylate cyclase-activating peptid e, and helospectin. Clusters of ganglia with cell bodies containing ac etylcholinesterase, or one of these six immunoreactive components, wer e found in the dorsal capsule. Coarse ner ire trunks expressing these immunoreactive components extended from the ganglia, and divided into varicose terminals in the capsule and intraglandular smooth muscle str ands, and gave off further branches, which surrounded acini and accomp anied ducts. The labelling for nitric oxide synthase generally coincid ed with that for vasoactive intestinal peptide within cell bodies and nerves of various types. Cell bodies, nerve trunks and varicose termin als showing labelling for pituitary adenylate cyclase-activating pepti de and helospectin were generally also labelled for vasoactive intesti nal peptide. The innervation pattern suggests that nitric oxide may ac t in concert with vasoactive intestinal peptide and related peptides i n the control of prostatic smooth muscle activity and secretion.