[The strategy of the "useful sun" improves physical endurance and structural adaptation in the myocardium].

The action of solar light transformed by special screens has been studied on CD-1 male mice. In the active control group, mice were irradiated through screens absorbing the UV-component. In the experimental group, screens transforming the UV-component into the orange-red light were used. In the active control, changes in the swimming activity, as compared to the same parameter before irradiation, were manifested much less than in animals of the experimental group. A morphological analysis showed changes in the structure of all cardiomyocyte organelles studied: the relative area of mitochondria in the experimental mice increased by more than 20% compared to intact animals (p < 0.05). A significant increase in the area of the sarcoplasmic reticulum, by 23.4% (p < 0.05), and in the volume of the myofibrillar apparatus, by 19.4% (p < 0.05), was detected. The results of our experiment show that the irradiation with using an additional orange-red component improves the physical endurance 1.5 times and initiates morphogenetic processes in cardiac muscle cells.

Hemodynamic effects of peptide fragments of differentiation factor HLDF.

Hemodynamic activity of peptides from differentiation factor HLDF (promyelocytic HL-60 line) was studied on WKY and SHR-SP rats. Intravenous infusion of the test peptides was accompanied by changes in blood pressure and heart rate, which depended on the structure of peptides and functional activity of the organism and differed in normotensive and hypertensive animals.

Effect of cholinergic and adrenergic receptor blockade on arrhythmogenic activity of endothelin-1 during inhibition of nitric oxide synthesis in awake mice.

We studied the effects of blockade of nicotinic receptors in sympathetic and parasympathetic ganglia (hexamethonium), muscarinic receptors (atropine), and beta1-adrenoceptors (atenolol) on arrhythmogenic activity of endothelin-1 during inhibition of nitric oxide synthesis with Nomega-nitro-L-arginine in NMRI mice. Atropine reduced, while hexamethonium completely abolished the arrhythmogenic effect of endothelin-1 during nitric oxide synthase inhibition. Atenolol potentiated arrhythmogenic activity of Nomega-nitro-L-arginine, but endothelin-1 had no effect on the incidence of arrhythmias under these conditions.

Arrhythmogenic effects of endothelin-1 under conditions of NO-synthase blockade with L-NAME in NMRI mice.

Arrythmogenic effects of endothelin-1 were studied in NMRI mice under conditions of NO-synthase blockade with N omega-nitro-L-arginine methyl ester. Intravenous injection of endothelin-1 increased heart rate variability in awake mice. NO-synthase blockade potentiated the arrythmogenic effects of endothelin-1. In narcotized animals the arrythmogenic effect of endothelin-1 was not observed and was considerably weakened under conditions of NO-synthase blockade. Arrhythmia was paralleled by atrioventricular block and lengthening of the ST segment.

[The weak neurotoxin from Naja kaouthia Cobra venom decreases the arterial blood pressure in rats]. / Slabyi neirotoksin iz iada kobry Naja kaouthia snizhaet arterial'noe davlenie u krys.

The weak neurotoxin from the Naja kaouthia cobra venom was found to reduce, under the intravenous administration to rats, the arterial blood pressure and increase the heart rate.

[Quantitative characteristics of the systemic anaphylaxis model in Sprague-Dawley rats]. / Kolichestvennaia kharakteristika modeli sistemnoi anafilaksii u krys linii Spreig-Douli.

Anaphylactic response intensity was quantitatively estimated by means of measuring mean arterial pressure (MAP) and heart rate (HR). Damage to intestinal mucosa was studied by means of morphometry. These indices grew in a dose-dependent way along with the amount of administered egg ovalbumin (OVA). The MAP and HR measurements seem to be useful in a quantitative elucidation of allergic sensitivity in laboratory animals.