Effect of carbon disulphide on the cardiovascular system

Biochemical, histological and electron-microscopic examinations of the heart and the aorta of albino rats exposed to carbon disulphide in concentrations of 10, 50, 100 and 200 mg . m-3 were carried out. Changes in the metabolic and energetic processes in the myocardium and in the quantitative and qualitative characteristics of the connective tissue of the aortal vessel wall were observed. The established disorders follow the dose-effect dependence. The authors studied the effect of carbon disulphide in concentrations of 10 and 50 mg . m-3 on the electrophoretic spectrum of serum proteins, the quantitative and qualitative characteristics of fibrous structures in the myocardium and the aorta of albino rats fed on atherogenic diet (cholesterol, cholic acid and vitamin D2). The combination of carbon disulphide with the atherogenic factor leads to intensification of changes in the cardiovascular system and in serum proteins, observed after independent exposure to either of the factors. The combination of atherogenic diet and 10 mg . m-3 carbon disulphide induced symptoms of intoxication, decreased survival of the animals, and the developing sclerotic process was found to be more severe and to progress more rapidly than in animals subject to atherogenic diet alone. The obtained results testify to cardiovascular effect of carbon disulphide. The observed atherogenic effect of carbon disulphide in low concentrations is most probably connected with its direct effect on the myocardium and the vessels.     

Effect of chronic uremia on the cardiovascular alpha 1 receptor

Adrenergic dysfunction in uremia has been well described. Several lines of evidence suggest disorders of blood pressure regulation and myocardial response may occur secondary to adrenergic dysfunction; attenuated pressor response to norepinephrine (NE) in uremia; attenuated chronotropic responses during dialysis induced hypotension. Since the adrenergic receptors are the effector component of the adrenergic nervous system, we have employed the partially nephrectomized uremic rat, to examine the effect of chronic uremia (4-6 weeks) on the binding properties of alpha 1 receptors in rat mesenteric artery and myocardial tissue. The results indicate that moderate levels of uremia alter the binding properties of both the alpha 1 vascular and myocardial receptor.     

Recovery rate of the cardiovascular system in rabbits following short-term halothane anesthesia.

Mean arterial pressure, cardiac output and heart rate were determined in eight male New Zealand white rabbits while conscious and after being anesthetized with halothane plus nitrous oxide for 15 minutes. Delivery of the anesthetic agent was stopped and the measurement repeated at 15, 30, 60 and 210 minutes. In a separate experiment blood samples were obtained for plasma renin activity in six rabbits before anesthesia, after 15 minutes of halothane plus nitrous oxide administration, and again 210 minutes after cessation of the anesthesia. Later, this experiment was repeated with the same rabbits except that they were allowed to breathe room air instead of the anesthesia. The halothane anesthesia resulted in decreased mean arterial pressure and cardiac output, but these returned to the preanesthetic levels by 15 minutes after stopping the anesthesia. Heart rate increased during halothane administration, and although it tended to return toward control levels after cessation of the halothane, heart rate was still elevated 210 minutes later. Halothane plus nitrous oxide produced an increase in plasma renin activity, which then subsided to normal by 210 minutes following anesthesia; breathing room air did not result in increases in plasma renin activity. These studies revealed that although short-term anesthesia with halothane plus nitrous oxide resulted in cardiovascular changes in rabbits, after cessation of the anesthetic agent the cardiovascular system quickly returned to normal.     

Effect of rubomycin and carminomycin on suppressor cells participating in the regulation of the immune response

The effect of rubomycin and carminomycin on induction of suppressor cells in immunization of mice with high doses (2 . 10(9) cells) of sheep red blood cells (SRBC) or with the allogeneic spleen cells was studied. When the spleen cells of syngeneic animals hyperimmunized with SRBC were administered to intact cells, a marked specific suppression of both the antibody formation and the reaction of the delayed type hypersensitivity were observed. A decrease in the suppressor activity or its complete elimination as a result of exposure of the spleen cell donors to the antibiotics was indicative of a relatively selective effect of these drugs on the suppressor cells. This effect of the antibiotics increased after treatment of the spleen immune cells with the anti-T-serum and complement. However, the blocking effect of the antibiotics on the suppressor cells was not strictly specific, since they were detected in the syngeneic and allogenic systems with the cell transfer.