Innervation of the large arteries and heart of the toad (Bufo marinus) by adrenergic and peptide-containing neurons.
The innervation of the major arteries and heart of the toad (Bufo marinus) was examined by use of glyoxylic acid-induced catecholamine fluorescence and peptide immunohistochemistry. All arteries possessed a moderate to dense plexus of adrenergic axons, which also showed neuropeptide Y-like immunoreactivity (NPY-LI). Some adrenergic axons in the intracardiac vagal trunks showed NPY-LI, but the varicose adrenergic axons innervating the cardiac muscle of the atria and ventricle, and the coronary blood vessels did not display NPY-LI. About half of the nerve cell bodies in the anterior sympathetic chain ganglia with dopamine-beta-hydroxylase-LI (DBH-LI) also contained NPY-LI. The nerve cell bodies with DBH-LI alone were generally larger (median diameter 30 micron) than those with both DBH-LI and NPY-LI (median diameter 20 micron). Some cell bodies showing DBH-LI alone were surrounded by boutons with NPY-LI but not DBH-LI. Axons that displayed simultaneously both substance P-LI (SP-LI) and calcitonin gene-related peptide-LI (CGRP-LI) also formed a plexus around all arteries studied, being particularly dense around the mesenteric and pulmonary arteries. These axons are most likely sensory since SP-LI was reduced by capsaicin treatment, and nerve cell bodies with both SP-LI and CGRP-LI were found in dorsal root ganglia and the vagal ganglion. A dense plexus of axons showing somatostatin-LI was located around the pulmonary artery and its main intrapulmonary branches. A few nerves with vasoactive intestinal polypeptide-LI were found around the dorsal aorta and pulmonary artery. No perivascular nerves with enkephalin-LI were observed. Reversed-phase, high-pressure liquid chromatography of acid extracts of the large arteries showed that the major peaks of NPY-LI and SP-LI co-eluted with porcine NPY (1-36) and synthetic SP (1-11), respectively. Thus, the location and structure of these peptides in perivascular nerves has been highly conserved during vertebrate evolution.
J L
JL
Morris
I L
IL
Gibbins
G
G
Campbell
R
R
Murphy
J B
JB
Furness
M
M
Costa
D000320:Adrenergic Fibers / Q000032:analysis / Q000502:physiology*; D000818:Animals; D001369:Axons / Q000032:analysis; D002024:Bufo marinus; D015740:Calcitonin Gene-Related Peptide; D003331:Coronary Vessels / Q000032:analysis / Q000294:innervation*; D005260:Female; D005727:Ganglia, Spinal / Q000032:analysis; D005728:Ganglia, Sympathetic / Q000032:analysis; D006329:Heart Conduction System / Q000032:analysis*; D008297:Male; D009419:Nerve Tissue Proteins / Q000032:analysis* / Q000502:physiology; D009475:Neurons, Afferent / Q000032:analysis*; D009478:Neuropeptide Y; D009620:Nodose Ganglion / Q000032:analysis; D013004:Somatostatin / Q000032:analysis; D013373:Substance P / Q000032:analysis; D014660:Vasoactive Intestinal Peptide / Q000032:analysis
D009419:Nerve Tissue Proteins; D009478:Neuropeptide Y; D013373:Substance P; D014660:Vasoactive Intestinal Peptide; D013004:Somatostatin; D015740:Calcitonin Gene-Related Peptide