[Electrical activity and circulatory effects of nitrite in the rat cerebrum].

An association between the cerebrum electrical activity (CEA) in rats, blood supply of its cortex microregions (linear blood flow), and general cerebrum blood flow under acute nitrite hypoxia was studied. The phase character of the change in hemodynamic indices and the total capacity of electroencephalography (EEG) spectrum for 75 min after sodium nitrite introduction (30 mg/kg of body weight) was detected. The first phase (30 min) was associated with cerebrum adaptation to hypotension caused by nitrite and was completed by EEG normalization.

[Myocardial electrogenesis in laboratory rats under conditions of acute nitrite intoxication].

In anesthetized male rats the arterial blood pressure in femoral artery and electrocardiogram in standard leads were recorded uninterruptedly for 1-1.5 h under conditions of acute nitrite intoxication produced by a subcutaneous injection of water solution of sodium nitrite (donor of nitric oxide) at concentrations of 10, 30, and 50 mg/kg body mass. Results of the study have shown dose-dependent changes of arterial pressure as well as of time and amplitude characteristics of electrocardiogram under effect of NaNO2.

[Effect of nitrite-induced methemoglobinemia on the kinetics of blood deoxygenation].

Kinetics of blood deoxygenation was studied during acute hypoxia induced by subcutaneous administration of sodium nitrite using polarographic method. Plasma oxygen tension remained unaltered as the dose of sodium nitrite increased, while the dynamics of oxygen release was dose-dependent. The constant of oxyhemoglobin deoxygenation rate proved to vary with blood deoxygenation.

[Bioelectrical reactions on the surface of the mamma in the goat].

Spontaneous and evoked biopotentials were recorded on the mammary gland surface in goats. The biopotentials appear in the course of secretion during milk ejection as well as under electrical, mechanical and hormonal actions. They might be considered as adequate indices of secretion and ejection processes in the mammary gland.

[The comparative characteristics of the heart rhythm in cetaceans].

In Amazon River dolphins, bottle-nosed dolphins and white whales, comparative studies have been made on cardiac electrical activity using electrocardiographic and telemetric techniques. In all the species investigated, certain dependence of cardiac cycle duration on the phase of respiratory pause was observed. A pronounced bradycardia was noted in diving animals which reflects the level of their adaptation to hypoxia and hypoxemia.