The study of reinnervation of gastric vagus nerves after lesser curvature and fundus myotomy in cats

The aim of this study was to investigate the reinnervation of gastric vagus nerves after lesser curvature and fundus myotomy (LCFM) in cats. After injection of the retrogradely tracing agent horseradish peroxidase (HRP) into the stomach wall along the predicted line of LCFM, the neuronal cell bodies of the afferent and efferent fibers were well-defined in both the nodose ganglia (NG) and dorsal motor nucleus of the vagus nerve (DMNx), respectively. The animals were divided into three subgroups. After LCFM, at intervals of 0 day, 2, 4, 6, 8, 10 and 12 weeks, respectively, they were processed for a HRP histochemical study in both subgroups A and B. In subgroup A, HRP was directly injected into both sides of the stomach wall distal to the dissecting plane of LCFM. A further corpoantral circumferential myotomy (CACM) was performed in subgroup B to eliminate the possibility of collateral sprouting via antropyloric vagus innervation before applying HRP to the same sites as those of subgroup A. Both LCFM and CACM with an overlapping suture were performed in subgroup C, and HRP was then injected into sites similar to those of subgroup A on the twelfth postoperative week. HRP-labeled cells were found in the NG on the sixth week and in the DMNx on the eighth week in subgroups A and B. The labeled cells increased in number until the twelfth week in both subgroups A and B. However, cells found in subgroup A were always more numerous than those found in subgroup B in both the NG and DMNx at equivalent time intervals. No labeled cell was found in the NG or DMNx in subgroup C during the 12 week study period.(ABSTRACT TRUNCATED AT 250 WORDS)