DISTRIBUTION OF NADPH-DIAPHORASE AND NITRIC-OXIDE SYNTHASE-CONTAININGNEURONS IN THE INTRAMURAL GANGLIA OF GUINEA-PIG URINARY-BLADDER

The cell population and distribution of NADPH-diaphorase positive and NOS immunoreactive intramural ganglion cells were examined on stretche d whole-mount preparations of the guinea pig urinary bladder which was divided into 3 regions: base, body and dome. The results showed that the highest frequency both of NADPH-d and NOS positive neurons was obs erved in the bladder base. Cell counts in the whole bladder showed tha t the number of NADPH-d positive neurons was much more than that of NO S immunoreactive neurons. Using neuron specific enolase (NSE) positive neurons as a reference (100%), NADPH-d positive neurons accounted for 84% while NOS immunoreactive neurons only made up 45% of the total ne uronal population. These results, along with previous studies on the f unction of nitric oxide, suggest that nitric oxide may be involved in the relaxation activity in the bladder base during micturition. The si gnificant difference in the number of NADPH-d positive and NOS immunor eactive neurons suggests that the localisation of one enzyme does not necessarily reflect the presence of the other.