NO synthase in cholinergic nerves and NO-induced relaxation in the rat isolated corpus cavernosum
1999 (English)In: British Journal of Pharmacology, ISSN 0007-1188, E-ISSN 1476-5381, Vol. 127, no 2, 349-360 p.Article in journal (Refereed) Published
- In the rat corpus cavernosum (CC), the distribution of immunoreactivity for neuronal and endothelial NO synthase (nNOS and eNOS), and the pattern of NOS-immunoreactive (-IR) nerves in relation to some other nerve populations, were investigated. Cholinergic nerves were specifically immunolabelled with antibodies to the vesicular acetylcholine transporter protein (VAChT).
- In the smooth muscle septa surrounding the cavernous spaces, and around the central and helicine arteries, the numbers of PGP- and tyrosine hydroxylase (TH)-IR terminals were large, whereas neuropeptide Y (NPY)-, VAChT-, nNOS-, and vasoactive intestinal polypeptide (VIP)-IR terminals were found in few to moderate numbers.
- Double immunolabelling revealed that VAChT- and nNOS-IR terminals, VAChT- and VIP-IR terminals, nNOS-IR and VIP-IR terminals, and TH- and NPY-IR terminals showed coinciding profiles, and co-existence was verified by confocal laser scanning microscopy. TH immunoreactivity was not found in VAChT-, nNOS-, or VIP-IR nerve fibres or terminals.
- An isolated strip preparation of the rat CC was developed, and characterized. In this preparation, cumulative addition of NO to noradrenaline (NA)-contracted strips, produced concentration-dependent, rapid, and almost complete relaxations. Electrical field stimulation of endothelin-1-contracted preparations produced frequency-dependent responses: a contractile twitch followed by a fast relaxant response. After cessation of stimulation, there was a slow relaxant phase. Inhibition of NO synthesis, or blockade of guanylate cyclase, abolished the first relaxant phase, whereas the second relaxation was unaffected.
- The results suggest that in the rat CC, nNOS, VAChT-, and VIP-immunoreactivities can be found in the same parasympathetic cholinergic neurons. Inhibitory neurotransmission involves activation of the NO-system, and the release of other, as yet unknown, transmitters.
Place, publisher, year, edition, pages
Wiley-Blackwell , 1999. Vol. 127, no 2, 349-360 p.
Penile erection, vesicular acetylcholine transporter protein, tyrosine hydroxylase, vasoactive intestinal polypeptide, heme oxygenase, carbon monoxide, guanylate cyclase
Medical and Health Sciences
IdentifiersURN: urn:nbn:se:liu:diva-59765DOI: 10.1038/sj.bjp.0702556ISI: 80540600006OAI: oai:DiVA.org:liu-59765DiVA: diva2:353388