CHOLINESTERASE BEHAVIOUR IN THE DENERVATED AND REINNERVATED MUSCLES

Abstract

Eighty chicks and 30 guinea pigs were used in the present investigations. The individuals of both species were divided into 4 groups. In the 1st group the muscles of the fore-limb in the chick, and those of the hind-limb in the guinea pig were denervated. In the 3rd group the corresponding muscles were denervated and the individuals were treated with DEP [diisopropyl fluorophosphate] doses sufficient to block the muscle ChEs [cholinesterases]. In the 2nd and 4th groups the muscle nerves were sectioned and subsequently sutured in order toobtaina speedy regeneration both in untreated and in DFP-treated animals. The animals of each group were sacrified at different time intervals within 90 days after the operation. Sixty days afte the operation the Koelle reaction was still positive, though somewhat reduced, at the level of the subneural apparatus in all the denervated muscle fibers of the 1st group, in both species. In the 2nd group, consisting of DEP-treated animals of both species, the Koelle reaction was negative in the motor end-plates of all the denervated muscle fibers through the entire time of the experiments (90 days), except in 2 out of the 6 guinea pigs which had survived poisoning. In all individuals, both untreated and DFP-treated, the subneural apparatuses of the reinnervated motor end-plates consistently exhibited a positive Koelle reaction coincidental with the achievement of nerve regeneration. No failure of ChE activity at the level of musculo-tendinous junctions was observed after denervation; a speedy recovery of the enzyme activity occurred at the same junctions of denervated fibers after DFP-treatment. Concerning the sarcoplasm, some of the denervated fibers exhibited a positive reaction shortly after the operation, both in the DFP-treated and untreated animals.