[Xanthine oxidase--xanthines as a system of endogenous regulation of phosphodiesterase activity]. / Ksantinoksidaza--ksantiny kak sistema éndogennoi reguliatsii aktivnosti fosfodiésterazy.

The paper is concerned with the data indicating close interaction between xanthinoxidase (Xase) and phosphodiesterase (PDE). PDE activity can be modified by affecting the activity of Xase. This effect is mediated by changes in the concentrations of endogenous xanthines. The action of PDE inhibitors, methylxanthines, is discussed from the point of view of the above effect. The data obtained hold promise for purposeful monitoring of tissue concentrations of the cyclic nucleotides in vivo and in vitro.

[Antihypoxic effect of analogs of cyclic adenosine monophosphate, phosphodiesterase inhibitors]. / Antigipoksicheskii éffekt analogov tsiklicheskogo adenozinmonofosfata--ingibitorov fosfodiésterazy.

A number of investigated cAMP derivatives are shown to inhibit the cAMP-phosphodiesterase in brain tissues of white rats in vitro. The 8-substituted aminoethylamino-derivatives proved to be effective inhibitors of the enzyme. Among them the most pronounced inhibition displayed the 8-(beta-aminoethylamino)-cAMP. In an in vitro experiment on the model of hypoxic hypoxia in rats it was shown to possess strong anti-hypoxic properties. The possible prospective clinical use of the cAMP analogs--inhibitors of the cAMP-phosphodiesterase--is discussed.

[Organ and tissue cyclic adenosine-3', 5'-monophosphate during the process of the body's adaptation to extreme factors]. / Tsiklicheskii adenozin-3'5'-monofosfat v organakh i tkaniakh v protsesse adaptatsii organizma k ekstremal'nym vozdeistviiam.

Various by nature extreme factors (hypoxic hypoxia, CO intoxication, chemical influence, noise and hypokinesia) caused similar changes in cAMP levels in different organs of albino rats (liver, the great cerebral hemispheres, heart). There was a significant increase in cAMP concentrations during the first stages of the influence and a progressive fall when the influence was continued. This fall was particularly expressed when the extreme factors used were of marked intensity. The authors consider the universality of the ascertained regularity to be a reflection of one of the central adaptive mechanisms of cell and the organism as a whole.

[Relation between oxidation and phosphorylation in gastric mucosa mitochondria]. / Sootnoshenie okisleniia i fosforilirovaniia v mitokhondriiakh slizistoi obolochki zheludka

The authors studied the state of cell respiration and oxidative phosphorylation in the mitochondria of the gastric mucosa at various phases of its function. Stimulation of secretion with histamine led to a distinct increase in the rate of mitochondrial respiration in the gastric mucosa against the background of a marked fall of the conjugation coefficient level, including P/O. The mentioned changes in the energy conjugation of mitochondria of the parietal cells preceeded activation of HCl secretion.