A histochemical evaluation of experimentally reinnervated canine laryngeal muscles

Sixteen dogs underwent different types of experimental reinnervation procedures of the posterior cricoarytenoid (PCA) muscle - reinnervation by the recurrent nerve itself (self-reinnervation) (n = 6), by the ansa cervicalis nerve (n = 5) or by the phrenic nerve (n = 5). After functional evaluation the normal left and the reinnervated right PCA muscles were removed for histochemical analysis. Cryostat sections were incubated for actomyosin ATPase, NADH-TR and alpha-GPDH. All muscles showed microscopical evidence of successful reinnervation. There was a slight change in the muscle fiber type composition in the reinnervated muscle as compared to the normal side. Incubations for the NADH-TR and alpha-GPDH showed less staining intensity in the reinnervated muscles. The histochemical differences between normal and reinnervated muscles were small, however, and probably of minor importance with regard to the function of the muscles.