Visceral and somatic afferent origin of calcitonin gene-related peptide immunoreactivity in the lower thoracic spinal cord of the rat.
The origin of calcitonin gene-related peptide in the thoracic spinal cord of the rat was investigated by radioimmunoassay and immunohistochemistry. In transverse sections from normal animals there was a dense staining of calcitonin gene-related peptide-immunoreactivity in laminae I, II and V of the dorsal horn. In parasagittal sections this was found to consist of rostrocaudally orientated fibres in laminae I and II and longitudinal bundles of fibres interspersed with a plexus of immunoreactivity in lamina V. After sectioning the thoracic spinal nerves there was a significant reduction in immunoreactivity in the dorsal horn of the spinal cord which was seen as a marked reduction of staining in lamina II and in the bundles of fibres in lamina V. Section of the splanchnic nerve slightly reduced staining in lamina I and virtually abolished the plexuses of immunoreactivity in lamina V. However, measurement of calcitonin gene-related peptide in samples from coeliac-ganglionized rats revealed an increase in immunoreactivity in regions of the spinal cord containing lamina V. These results provide evidence of a visceral and somatic afferent origin of calcitonin gene-related peptide in the thoracic spinal cord of the rat.
Sharkey
K A
KA
Department of Physiology, Medical School, University of Bristol, U.K.
Sobrino
J A
JA
Cervero
F
F
Varro
A
A
Dockray
G J
GJ
D000818:Animals; D015740:Calcitonin Gene-Related Peptide / Q000378:metabolism*; D007150:Immunohistochemistry; D008297:Male; D009475:Neurons, Afferent / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013116:Spinal Cord / Q000166:cytology / Q000378:metabolism*
D015740:Calcitonin Gene-Related Peptide