NITRIC-OXIDE SYNTHASE-IMMUNOREACTIVE, ADRENERGIC, CHOLINERGIC, AND PEPTIDERGIC NERVES OF THE FEMALE RAT URINARY-TRACT - A COMPARATIVE-STUDY

The distribution and frequency of NO synthase (NOS)-immunoreactive (IR ) nerves in relation to the general autonomic innervation, adrenergic, cholinergic and some peptidergic nerves, were investigated in the fem ale rat urinary tract. NOS nerves were very frequent in the smooth mus culature of the urethra together with cholinergic, adrenergic and neur opeptide Y (NPY)-IR nerves, whereas vasoactive intestinal peptide (VIP )-lR and calcitonin-gene-related peptide (CGRP)-IR nerves were much le ss abundant. NOS-IR, CGRP-IR and cholinergic nerves were also frequent in the longitudinal smooth musculature of the distal ureters and the ureteral orifices into the bladder, where no adrenergic, NPY-IR and VI P-IR nerves were found. In contrast, in the detrusor NOS-IR nerves wer e scarce. Bilateral pelvic ganglionectomy very pronouncedly decreased the number of any of the populations of nerves studied, whereas bilate ral pelvic decentralization selectively reduced the number of CGRP-IR nerves in all structures and locations. Outflow obstruction very overt ly reduced the number of NOS-LR nerves in parallel with the general au tonomic innervation. Thus, in the rat female urinary tract, NOS-contai ning nerves particularly occur in regions with sphincteric functions s uch as urethra and ureteric orifices. In these regions NO may exert a transmitter role, both directly or by interaction with other transmitt ers/modulators.