THE DISTRIBUTION AND COLOCALIZATION OF IMMUNOREACTIVITY TO NITRIC-OXIDE SYNTHASE, VASOACTIVE INTESTINAL POLYPEPTIDE AND SUBSTANCE-P WITHIN NERVE-FIBERS SUPPLYING BOVINE AND PORCINE FEMALE GENITAL ORGANS

The distribution of nitric oxide synthase-immunoreactive (NOS-IR) axon s and their relationship to structures immunoreactive to vasoactive in testinal poly peptide (VIP), substance P (SP) and tyrosine hydroxylase (TH) were studied by means of the nicotinamide adenine dinucleotide p hosphate-diaphorase (NADPH-d) technique or double-labelling immunofluo rescence in the genital organs of cow and pig. Relevant neurons were a lso investigated in the pig. NOS-containing neural structures were TH- immunonegative in bovine or porcine genital organs, or in the studied ganglia. In the bovine ovary, NOS-IR nerves were neither VIP-IR nor SP -IR, whereas in the pig, most NOS-containing axons were also VIP-IR. T he oviduct was supplied by single NOS/VIP- or NOS/SP-containing nerves , whereas in the uterus, NOS-IR axons were moderate in number, often b eing immunoreactive for VIP or SP. Numerous NOS/VIP-IR and NOS/SP-IR n erves were found in the vagina of both species. In all tissues studied , NOS-IR axons were mainly related to vascular smooth muscle. Most of the neurons of the paracervical ganglia and some neurons in dorsal roo t ganglia exhibited strong NOS activity. Only single neurons in sympat hetic ganglia were NADPH-d-positive. Most nitrergic neurons in the aut onomic ganglia were VIP-IR but SP-immunonegative. The sensory neurons were mostly NOS/SP-IR, whereas only single neurons co-expressed NOS an d VIP immunoreactivity.