title: A light and electron microscopic immunohistochemical study of vasoactive intestinal polypeptide- and substance P-containing nerve fibers along the cerebral blood vessels: comparison with aminergic and cholinergic nerve fibers.
abstract: Vasoactive intestinal polypeptide (VIP)- and substance P-containing nerve fibers were observed in the cerebral blood vessels using an immunohistochemical technique. VIP-containing nerve fibers distributed in a spiral pattern, similar to that of muscle cells. Under electron microscopic observation, VIP-immunoreactive terminals lay close to a muscle cell in the inner layer of the adventitia. In contrast, substance P-containing nerve fibers showed a meshwork pattern in the outer layer of the adventitia. Using both acetylcholinesterase (AChE) staining and VIP immunohistochemistry, AChE-positive and VIP-immunoreactive nerve fibers revealed almost the same distribution in the same specimen. The present data suggest that VIP-containing nerve fibers may play a role in the smooth muscle control of the blood vessels, whereas substance P-containing nerve fibers may not take part in muscle control.
mesh_terms: D000818:Animals; D001808:Blood Vessels / Q000294:innervation; D002560:Cerebrovascular Circulation; D006168:Guinea Pigs; D006651:Histocytochemistry; D007120:Immunochemistry; D008854:Microscopy, Electron; D009412:Nerve Fibers / Q000378:metabolism* / Q000648:ultrastructure; D010275:Parasympathetic Nervous System / Q000378:metabolism; D013373:Substance P / Q000378:metabolism*; D013564:Sympathetic Nervous System / Q000378:metabolism*; D014660:Vasoactive Intestinal Peptide / Q000378:metabolism*
chemical_list: D013373:Substance P; D014660:Vasoactive Intestinal Peptide