Abstract: Objective To study the distribution and proportion of neuropeptide containing nervers in the sinus node in cases of sudden manhood death syndrome(SMDS)and to explore the mechanism of SMDS.Methods Immunohistochemical staining and quantitative analysis of neuropeptide Y(NPY)and vasoactive intestinal peptide(VIP)in the sinus node in6cases of SMDS and in12cases of non-cardiac death(control group)were achieved by LSAB method and computerized image system.Results As for NPY positive materials,VIP positive materials and the ratio of VIP/NPY in the sinus nodes,there were no significant difference between the control group and SMDS group.Conclusion The mechanism of SMDS and the abnormality of autonomic nervous innervation in the sinoatrial nodes maybe incorrelation.

Key words: sudden manhood death syndrome, neuropeptide Y, vasoactive intestinal peptide, autonomic nervous system