PHYSICAL AND BIOCHEMICAL-CHANGES IN RIGOR MORTIS OF CARDIAC-MUSCLE

The development of rigor mortis in canine cardiac muscle has been investigated by measurements of changes in its compressibility with time after excision. These changes have been correlated with the progressive loss of the total adenine nucleotide pool. At 37°C the physical onset of rigor mortis commenced after 40 min in both anterior papillary muscle and subepicardial muscle but is apparently delayed in the more anisotropic midmyocardium to 75 min. However at all sites the relative change in compressibility was the same and complete rigor was attained by 100 min with the same percentage change in compressibility. The onset of rigor mortis commenced when the adenine content of the muscle had fallen by 62% and was complete when a 75% loss had occurred. © 1979.