Abstract
The new technic of Lundsgaard 1 for studying the chemical changes occurring in muscle during activity gives an opportunity for a new approach to the relationship between contraction and rigor. We have, therefore, studied the effect of mono-iodoacetate on the chemical processes of chloroform rigor, since the changes occurring in this form of rigor have been supposed to be similar to those of muscle contraction.
The muscles were soaked for 40 minutes in an oxygenated solution of Na mono-iodoacetate in Ringers (1 to 5000); one of the pair was treated with chloroform and the other analyzed for control. The control and experimental muscles were frozen at the same time, thinly sliced and extracted with trichloracetic. On this extract the various phosphate fractions and lactic acid were determined. The changes in the phosphate fractions and in lactic are in the table.
The decrease in phospho-creatine is more marked in the poisoned muscles than in those in which lactic acid is produced. Admitting the same interpretation as for muscle contraction one must conclude that phospho-creatine is the source of energy and that its resynthesis through the lactic acid mechanism is not interfered with. The high lactic acid values in relation to the extent of phospho-creatine resynthesis show this to be a wasteful process from the energy standpoint.
Get full access to this article
View all access options for this article.