[Effect of caffeine on the Ca2+-transport function of sarcoplasmic reticulum vesicles in the rat myocardium].

The effects of caffeine on active transport of Ca2 by heavy and light fractions of rat myocardial microsomes were investigated with the use of a Ca2+-selective electrode and nephelometry. It was found that under the effect of caffeine (5 mM) the rate of Ca2 transport in the presence of oxalate decreased by 30 to 40%. The caffeine-induced inhibition was prevented by ruthenium and tetracaine, thus suggesting the inhibitor specificity.

[Effect of acidosis on Ca2+ binding by the sarcoplasmic reticulum and on relaxation of the cardiac muscle].

A value of Ca2+ binding in 1 second by sarcoplasmic reticulum fragments from guinea pig hearts increased proportionally to elevation of Ca2+ concentration from 0.1 to 3.0(-6) M at pH 7.

[Metabolism of rat brain nonhistone proteins following alteration of nervous system function and training].

Metabolism of total nonhistone nuclear proteins (NNP) of the rat brain was studied in three groups of animals: trained, pseudotrained and control. Protein synthesis and degradation were estimated by determining NNP specific radioactivity 1, 3, 6 and 9 weeks after the precursor, 14C-lysine, injection. The experimental results indicate that there are two fractions of NNP which differ in their metabolic rates.