[125I]vasoactive intestinal polypeptide binding sites: quantitative autoradiographic distribution in the rat spinal cord.
The quantitative autoradiographic distribution of [125I]vasoactive intestinal polypeptide (VIP) receptor binding sites was investigated in the rat spinal cord. [125I]VIP binding sites are discretely distributed, with a rostro-caudal gradient, along the longitudinal length of the cord; highest densities of sites being observed in its lumbar and sacral segments. In transverse sections, highest levels of [125I]VIP sites are present in laminae I and II, around the central canal, and in the parasympathetic lateral horn of the sacral segment. Moderate densities are seen along the medial border of the dorsal horn and the sympathetic lateral horn of the thoracic cord. Low amounts of labeling are observed in most structures of the ventral horn while white matter areas are apparently devoid of specific [125I]VIP binding. Thus, the distribution of spinal [125I]VIP receptor sites correlates well with that of VIP-like immunoreactive materials and support possible roles for this peptide in sensory neurotransmission and in the control of autonomic functions.
Yashpal
K
K
Douglas Hospital Research Centre, Faculty of Medicine, McGill University, Montreal, Quebec, Canada.
Sarrieau
A
A
Quirion
R
R
D000818:Animals; D001345:Autoradiography; D001665:Binding Sites; D007457:Iodine Radioisotopes; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D011964:Receptors, Gastrointestinal Hormone / Q000378:metabolism*; D018005:Receptors, Vasoactive Intestinal Peptide; D013116:Spinal Cord / Q000378:metabolism*; D014660:Vasoactive Intestinal Peptide / Q000378:metabolism*
D007457:Iodine Radioisotopes; D011964:Receptors, Gastrointestinal Hormone; D018005:Receptors, Vasoactive Intestinal Peptide; D014660:Vasoactive Intestinal Peptide