The effect of analgesics on the coronary circulation

Summary The author studied the effect of analgesics (morphine, thecodin, phenadon and promedol) on the blood output from the coronary sinus and the tone of the coronary blood vessels in cats. Of the analgesics mentioned only morphine increases the cardiac blood supply. In the majority of cases the introduction of promedol and phenadon leads to a decrease of the volume velocity of the coronary blood flow, increasing the tone of coronary vessels. Thecodin exerts no material effect on the coronary circulation.Presented by Active Member AMN SSSR V. V. Zakusov     

The effect of potassium on the coronary circulation

Conclusion The influence of potassium on the coronary circulation was studied. Experiments were carried out on dogs under morphine-urethane anesthesia with the use of thermoelectric recording of the coronary circulation volume velocity, and with the resistography method with perfusion through the coronary artery at constant blood volume. Intracoronary and intravenous injections of different doses of potassium chloride caused coronary dilatation. Large doses led to cardiac arrest.In most of the cases there was a reduction of the cardiac blood supply after application of concentrated potassium chloride solution to the epicardium. However, it·increased in rare cases when the blood pressure was greatly elevated, thus compensating a slight rise of the coronary vessel tone. The coronary tone rose to a greater degree at the place of K application than in the remote zone.In these experiments the EKG changes seen were similar to those observed in myocardial infraction. They did not correlate with changes of coronary circulation.(Presented by Academician AMN SSSR V. V. Parin) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 59, No. 2. pp. 20–24, February, 1965     

The mechanism of papaverine's effect on the coronary circulation

Summary Experiments were carried out on anesthetized cats (urethane with chloralose). A preparation of isolated heart in situ was used. The conronary arteries of the recipient cat were perfused with the blood of the donor. For this purpose two types of pumps were used: with a constant perfusion volume and with a constant perfusion pressure. The absorption of oxygen by the heart was measured simultaneously, by the photometric method. The direct vasodilative effect of papaverine on the coronary vessels is not the main reason for increased volumetric rate of the coronary circulation provoked by papaverine. The main cause of this effect is augmented oxygen absorption by the heart under the influence of papaverine.(Presented by AMN SSSR Active Member V. V. Zakusov) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 53, No. 1, pp. 69–73, January, 1962     

The effect of some ganglion-blocking substances on the coronary circulation

Summary Acute experiments were performed on cats. The study of the effect of ganglioblockers (tetrammonium, hexonium, pentamine and mecamine) on the blood flow from the coronary sinus was carried out.The effect of these substances on the coronary circulation is variable and depends on the initial conditions of the blood supply of the heart.Tetrammonium in the dose of 2–10 mg per kg of body weight increases the blood flow from the coronary sinus by 10–40%. Hexonium (2–5 mg per kilogram) increases the blood flow from the coronary sinus by 25–40% in case of the average and low, initial values of the volume of the blood flow per minute. Hexonium in the above dose causes decrease of the volume velocity of the coronary blood flow by 20–40% in animals with intensive myocardial blood supply.In majority of cases pentamine in the dose of 2–5 mg per kilogram of body weight and mecamine in the dose of 0.5–2 mg per kilogram cause decreased blood flow from the coronary sinus.Submitted by Active Member AMS USSR V. V. Zakusov     

The effect of paraverine and dibazol on the rate of the coronary circulation

Summary The effect of papaverine and dibazol on the coronary blood flow was studied in short-term experiments on cats, anesthetized with nembutal in condition of artificial respiration. A method which allowed determination of the volume velocity of blood outflow from the coronary sinus was employed. Papaverine provokes a pronounced increase of the coronary blood flow. Dibazol on the other hand, causes only insignificant and temporary increase. When paraverine was administered after dibazol its effect on the coronary blood vessels was enhanced. Thus, combined administration of papaverine and dibazol reinforces their effect.Presented by Active Member Acad. Med. Sci. USSR, V. V. ZakusovDibazol is 2-benzyl-benzimidazol hydrochloride — Publisher's note.     

The effect of strophanthin on the coronary circulation and cardiac oxygen intake in experimental myocarditis

Summary Strophanthin given in therapeutic doses to healthy animals has no significant effect upon the coronary circulation and oxygen intake by the cardiac muscle. Toxic doses reduce the coronary circulation, the cardiac oxygen intake and the blood pressure; bradycardia appears. The dose of 20 g/kg, which causes no changes in the coronary blood flow or the cardiac oxygen intake in the healthy animals, considerably reduces these values in animals with experimentally induced myocarditis. The different qualitative reactions occurring in response to strophanthin administration to animals with experimentally induced myocarditis may be partially explained by the increased cardiac sensitivity to strophanthin in this condition and the intensified excitation of the vagus nerves; the reflex character of the latter effect follows from experiments with vagotomy.The data on the increase in strophanthin toxicity and the different qualitative reaction of the coronary circulation observed in experimental myocarditis should be taken into consideration by clinicians treating diseases of the cardio vascular system with cardiac glycosides.(Presented by V. V. Zakusov, Active Member of the AMN SSSR) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 50, No. 12, pp. 52–57, December, 1960