[Postnatal development of the masticatory muscles of the Wistar rat (Rattus norvegicus Berkenhout). A histochemical study].

Muscle biopsies of the mandible adductors of the Wistar rat (Rattus norvegicus Berkenhout) have been analyzed enzyme-histochemically for the investigation of the postnatal development (42.-126. d post partum) of their muscle fibers with special regards to the fiber types.

[Histochemical muscle fiber characterization of the masticatory muscles of the Wistar rat (Rattus norvegicus Berkenhout)].

224 muscle biopsies of the mandible adductors of the Wistar rat have been analyzed enzyme-histochemically for the investigation of their muscle fibre types. The myofibrillar adenosine triphosphatase (ATPase) and the succinic dehydrogenase (SDH) have been used in this investigation. The major part of the chewing musculature consists of muscle fibres of the type II, which can be subdivided into 3 subtypes, type IIA, IIB and TR.