Experimental evaluation of rigor mortis. I. Histochemical analysis of rat skeletal muscle in the early post-mortem period.

Histochemical investigation of rat skeletal muscle samples removed immediately post mortem from exercised rats gave the following results: (1) Of the oxidoreductase enzymes studied, there was a slight increase in the activity of cytochrome oxidase. (2) There was no change in the acid- and alkali-stable actomyosin ATPase activity. (3) There was a notable decrease in glycogen concentration. In the case of strychnine intoxication: (1) There was no change in oxidoreductase enzymes. (2) There was an increase in the activity of alkali-stable ATPase in white fibres. (3) The glycogen concentration notably decreased. There was no change in the activity of enzymes studied in those animals sacrificed by anoxia.