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Biomedical subjects

M A Navakatikian

Publications and source records attributed to M A Navakatikian.

At least 19 recordsLinked to original sources

[Effect of several catecholamines on pulmonary circulation].

In anesthetized dogs, i. v. injections of 0.1-1.0 mcg/kg adrenaline, noradrenaline, and isadrine evoked a raise of blood pressure in the right ventricle of the hear by 13-200%. The greatest pressor effects were obtained with isadrine, the smallest those--with noradrenaline. In experiments with closed chest animals with perfusion of lungs lobe by venous blood under constant pressure and recording of blood flow with photoelectric drop recorder, injections into perfusate of 0.02-32.0 mcg adrenaline and noradrenaline diminished blood flow and increased vascular resistance. In 1/3 of cases isadrine evoked the same reaction, in other cases it increased blood flow in perfused lobe and decreased resistance. The isadrine effect was blocked by beta--blocking agent inderal, whereas those of adrenaline and noradrenaline--by alpha-blocking drug phentolamine. Adrenaline and noradrenaline to constrict the pulmonary vessels by activating the vascular alpha-adrenoreceptors. Isadrine can dilate and constrict the lung vessels. In intact circulation isadrine seems to cause vasoconstriction and elevate blood pressure in lesser circulation.

Animals↗

[The effect of microwave irradiation on the status of the thyroid gland].

Multiple irradiation of rats with microwaves of continuous generation (2450 MHz, 1 mW/cm2) increased and of pulsed generation (3000 MHz, 0.1 to 2.5 mW/cm2) decreased the functional activity of the thyroid gland with no changes in the triiodothyronine and thyroxin in blood serum. The role of the thyroid gland in inducing behaviour effects of microwaves was demonstrated by the method of extirpation.

Animals↗

[Changes in the activity and conditioned-reflex behavior of white rats during and after chronic microwave irradiation].

Albino rats were exposed to chronic (1-3 months) electromagnetic radiation (2375 MHz; 1, 5, 10, 50 and 500 microW/cm2; 7 hours a day). Inhibition of the activity during the open field tests and diminution of consolidation of the defence conditioned reflexes in a shuttle chamber occurred during exposure (5 to 500 microW/cm2) while the activity increased and reflexes consolidation gradually normalized during the post-irradiation period.

Animals↗

[An effect of delayed behavioral activation during a single exposure to microwaves].

Behavioural aspects of the effect of a single microwave exposure (2450 MHz; 1 mW/cm2; 0.27 mW/g; 7 h) were studied on albino rats using the labyrinth method and registering various constituents of the motor activity on days 1 and 4 after irradiation. No changes were found during the first 24 hours and an increase in the activity was noted on day 4 following irradiation.

Animals↗