IMMUNOHISTOCHEMICAL RESEARCH ON CGRP AND SP IN THECANINE MAIN SUPERFICIAL CARDIAC PLEXUS / 解剖学报

ABSTRACT

Objective To investigate the chemical properties of superficial cardiac neurons. Methods By means of immunohistochemical ABC technique,the study was performed concerning the distribution of calcitonin gene-related peptide(CGRP) and substance P(SP) in the canine main cardiac superficial plexus. Results CGRP-immunoreactive(IR) neurons were found in every plexus,but SP-IR neurons could be observed only in dorsal atria plexus(DAP),inter atria plexus(IAP) and aorta-pulmonary plexus(A-PP).The shape and size of CGRP-IR and SP-IR neurons were similar.The comparative study on atria and ventricles indicated that CGRP-IR and SP-IR neurons in atria were more than those in ventricles.Numerous CGRP-IR,SP-IR nerve fibers could be observed in each fat pats and intermyocardiocytes.These nerve fibers were usually situated near blood vessels,or were attached to vessel wall.Somewhat CGRP-IR and SP-IR nerve fibers were connected with myocardiocytes in some regions.Conclusion The results indicated that actually existed two peptides in canine cardiac superficial plexus.These implied that the regulations of the two kinds of peptidergic neurons to atria and ventricle were different.The two kinds of neurons mentioned above were likely to perform different or similar functions in canine heart.CGRP and SP could possibly modulate the activities of myocardiocytes and vessels of heart directly.