Rate Of Oxidative Metabolism Research Articles

A comparative study of cytoarchitectonics and chemoarchitectonics of the cerebral cortex of the guinea pig.

The histochemical distribution of succinic dehydrogenase in the guinea pig's cerebral cortex is compared with the cytoarchitectonics in restained sections. The cytoarchitectonic subdivision of the cortex is paralleled by gradations of enzymic activity which can be substantiated by densitometric measurements. The typical histochemical patterns of several representative regions are described. The histochemical pattern of succinic dehydrogenase may be regarded as a parameter of the general oxidative metabolic rate of a region. A more detailed comparison of chemoarchitectonics and cytoarchitectonics shows that there is no correlation of cell density and enzymic activity since the nerve cell's maximal enzyme supply can be found either in the pericaryon or in the dendrites. These patterns of enzymic distribution are typical for the various laminae of the cortex.

Oxygen consumption and blood flow in the hypothermic, perfused kidney.

Temperature was diminished in a stepwise fashion in the isolated kidney of the dog perfused from a peripheral artery of the original, normothermic animal. Decreased temperature resulted in an appreciable reduction of renal blood flow at constant arterial blood pressure. Increased blood viscosity and vasoconstriction were both responsible for this reduction of flow. Hypothermia also resulted in a reduction in arteriovenous oxygen difference which was roughly proportional to the centigrade temperature. Furthermore, hypothermia exerted a marked but reversible depression of the rate of oxidative metabolism. This effect was relatively more severe than the changes for the body as a whole at equivalent temperatures reported by other investigators.

Effects of Temperature and Plant Species upon the Rates of Metabolism of Systemically Applied Di-Syston12

The rates of oxidative metabolism and of hydrolytic decomposition of Di-Syston®, or O,O -diethyl S -ethyl-2-thiocthyl phosphorodithioate (formerly called Bayer 19689) were measured at various temperatures and in several plant species using a p32- radiotracer. The rates of oxidation of the Di-Syston metabolites in isolated cotton leaves were accelerated by increased temperatures between 87° and 100° F., lind from the Arrhenius energy of activation 10,200 cal. per mole it was determined that the rate of oxidation of Di-Syston sulfoxide increased about 1.9 times for each 10° C. rise in temperature. Metabolism of Di-Syston sulfoxide and hydrolytic decomposition of the toxic products occurred from 2 to S times as fast in tomato leaves at 70° F. as in cotton leaves. The rates in a number of other plants studied appreared to be intermediate between those in tomato and cotton.