[Morphometric assessment of gender differences in human constitution].

In 154 girls and 58 young men aged 17-21 years, a new body mass index (BMI2 = M/H3), body form index (BFI=S/M2/3), body build index IBBI = (M/H3)1/2], and body fatness index (BFI = M/HC2) were determined; in which C, H, M, S correspond to the wrist circumference, body height, body mass and body area. It was shown that all the indices mentioned demonstrated highly significant gender differences if calculation of each of them was based, not on the body mass, but on a conventional body volume obtained by division of the factual body mass by the average statistical body density corresponding to 1.064 kg/dm3 in men and 1.

[Resonance hypothesis of heart rate variability origin].

A hypothesis is advanced of the heart rate variability being subjected to beat-to-beat regulation of cardiac cycle duration in order to ensure the resonance interaction between respiratory and own fluctuation of the arterial system volume for minimization of power expenses of cardiorespiratory system. Myogenic, parasympathetic and sympathetic machanisms of heart rate variability are described.

[The spectrogram of heart rate in cats following burst stimulation of the vagus nerve].

Denervation of the heart (bilateral vagotomy and propranolol) in artificially ventilated cats didn't remove respiratory peaks on the spectrogram of heart rate, while burst stimulation of vagus nerve increased or decreased them several times by synchronization of the heart and vagus rhythms, which in its turn was observed under the bradycardia only. At the same time, the desynchronization of rhythms provoked severe sinus arrhythmia which had a distinct periodic character. Under these conditions, there were high non-respiratory peaks appearing at the spectrogram of the heart rate that indicated existence of two vagus chronotropic effects: a well known tonic one and special intracycle synchronizing effect correcting duration of every cardiac cycle.

[Adaptive-compensatory changes of autonomic balance in children with infantile cerebral paralysis].

In children of 6-7 years old with infantile cerebral paralysis the heart muscle mobilization is observed that displays in heart rate acceleration, decrease of its variability and some diminuation of adaptive reserves of cardiovascular system. As a result of such adaptation strain the adequate maintenance of the principal hemodynamic parameter (average arterial pressure) is ensured.

[The components of the negative chronotropic effect of the vagus nerve on the heart and a method for their definition].

Stimulation of the peripheral end of the right n.vagus led to synchronizing of the vagal and cardiac rhythms in anesthetised cats. The stimulation of the n.

[The effect of certain ions on the realization of the phase-dependent action of the vagus nerve on the heart rhythm in cats].

In cats, magnesium, potassium and finoptin diminished the vagal chronotropic effect whereas calcium potentiated it. In potassium chloride administration, the vagotropic action was due to a selective diminishing of the tonic component.

[The effect of endogenous enkephalins on the phenomenon of the synchronization of vagus and cardiac rhythms].

The effect of met- and leu-enkephalins in cats was characterised by depressing vagotropic action due to a selective decrease in the tonic component. The potentiation of synchronizing actions may serve as an index of a reliable and stable mechanism of the beat-by-beat control of the cardiac rhythm.

[The specific nature of vagus influences on the heart rhythm under the action of humoral regulators].

Effects of taurin, somatostatin, serotonin and noradrenaline upon the vagal chronotropic action and its components were studied in anesthetised cats. The data obtained suggests the existence of a specific transmitter link for vagal tonic and synchronizing effects upon cardiac rhythm.

[The vagotropic action of peptides isolated from the brain of hibernating susliks].

Dipeptide ASP-TYR extracted from the brain of hibernating squirrels was found to potentiate vagal effect on the cardiac rhythm, whereas pentapeptide neokyotorphin--to diminish it. In both cases the effect was due to an alteration of the tonic component's strength in the vagal chronotropic effect. The selective peptidergic modulation of the vagal effect on the cardiac rhythm suggests different physiological roles of the tonic and synchronizing components in regulation of the heart.

[The effect of a single firing stimulation of the vagus nerve on atrioventricular behavior of stimulation in the cat heart].

Dromotropic vagal effect was shown to consist of a prolonged tonic component and a short-term one depending on the interval between the burst irritation of the vagus nerve and the P-wave of the ECG.