Changes in Phosphate Compounds during the Development and Maintenance of Rigor Mortis

From the ¹ From the Department of Animal Biology, School of Veterinary Medicine, and the Graduate Groups on Molecular Biology and Biochemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104

Rigor mortis was induced in frog sartorii from female Rana pipiens by incubating the isolated muscles in 0.38 mm 2,4-dinitrofluorobenzene Ringer's (frog) solution for 90 min at 0°. This compound completely inhibits adenosine triphosphatecreatine phosphotransferase in vivo and eventually induces rigor mortis as characterized by shortening of the muscle to 50% of its rest length and the development of stiffness. As the muscle began to shorten the rate of ⁴⁵Ca efflux increased and the ATP level fell from 3.80 to 0.0 µmoles per g. There was a lack of correspondence between ATP breakdown and appearance of inorganic phosphate, which can be explained by leakage of inorganic phosphate from the muscle and by an increase in the concentration of glucose 6-phosphate, fructose 6-phosphate, and glucose 1-phosphate. The frog sartorius muscle breaks down ATP during a working contraction and in the shortening phase of rigor mortis. There is no ATP requirement for tension maintenance in rigor mortis after the muscle has finished shortening.

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?