Abstract.
The nitric oxide synthase-immunoreactivity and NADPH-diaphorase activity of intracardiac neurones in the rat and guinea-pig was studied at the ultrastructural level. While some nitric oxide synthase-containing intracardiac neurones were very heavily labelled, with electron-dense immunoprecipitate distributed throughout the neuronal cell bodies and their processes, most of the labelled neurones exhibited a lighter and more patchy distribution of nitric oxide synthase-immunoreactive material. Synapses made by nitric oxide synthase-negative nerve fibres with labelled intracardiac neurones were seen. Conversely, many nitric oxide synthase-containing nerve fibres that made synaptic contacts with unlabelled intracardiac neurones were also observed. Some small granule-containing cells were nitric oxide synthase-immunoreactive and were associated with unlabelled nerve terminals, while non-immunoreactive small granule-containing cells that were innervated by nitric oxide synthase-immunoreactive nerves were also seen. Small patches of osmiophilic electron-dense material were observed in the cytoplasm of NADPH-diaphorase-positive intracardiac neurones. This is the first description of the ultrastructural distribution of nitric oxide synthase-immunoreactivity and NADPH-diaphorase activity in a subpopulation of intracardiac neurones of rat and guinea-pig heart and provides further evidence in support of a role for nitric oxide in the local control of the heart by intrinsic neurones.
Similar content being viewed by others
Author information
Authors and Affiliations
Additional information
Received: 3 July 1995 / Accepted: 27 October 1995
Rights and permissions
About this article
Cite this article
Sosunov, A., Hassall, C., Loesch, A. et al. Nitric oxide synthase-containing neurones and nerve fibres within cardiac ganglia of rat and guinea-pig: an electron-microscopic immunocytochemical study. Cell Tissue Res 284, 19–28 (1996). https://doi.org/10.1007/s004410050563
Issue Date:
DOI: https://doi.org/10.1007/s004410050563