Alterations in systemic hemodynamics caused by electrostimulation of the ventral medulla oblongata

Alterations in arterial blood pressure induced in cats by electrostimulation of pressor or depressor points in the ventral part of the medulla oblongata did not, as a rule, differ in direction from those in other hemodynamic parameters, including cardiac output, total peripheral resistance, central venous pressure, maximal acceleration of aortic blood flow, heart rate, venous return, blood flow in the superior and inferior venae cavae, and arterial inflow to and venous outflow from the posterior part of the body. It is postulated that the ventral medulla exerts direct influences on both the venous and arterial hemodynamics. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 121, No. 6, pp. 613–618, June, 1996     

Correlation between blood pressure and parameters of systemic hemodynamics during pressor and depressor effects of the ventral medulla oblongata

Correlation between blood pressure and parameters of systemic hemodynamics was studied on cats using electrical stimulation of the ventral medulla oblongata. Changes in blood pressure induced by presoor activation were related to venous hemodynamics in the anterior rather than posterior vena cava. Venous blood flow is assumed to be involved in hemodynamic changes caused by stimulation of pressor centers but not depressor centers in the ventral medulla oblongata. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 129, No. 1, pp. 16–19, January, 2000     

Effect of prostaglandin B1 on the systemic and regional hemodynamics

The effect of prostaglandin B₁ (PGB₁) on the cardiovascular system was studied in experiments on anesthetized dogs. After intravenous injection of PGB₁ (40 g/kg in a single dose) arterial hypotension tachycardia, increased myocardial contractility, an increased cardiac output, and a rise of pressure in the pulmonary artery were observed. The total peripheral resistance and total pulmonary resistance were reduced. The work of the right and left ventricles was increased. The coronary blood flow was increased by 29%. The mean velocity of the volume blood flow in the renal and femoral arteries was appreciably increased after administration of PGB₁, but in the common carotid and superior mesenteric arteries the increase was not significant. Changes in the systemic and regional hemodynamics were of short duration.Department of Pharmacology, I. M. Sechenov First Moscow Medical Institute. Department of Anesthesiology, Institute of Clinical and Experimental Surgery, Ministry of Health of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR V. V. Zakusov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 83, No. 2, pp. 131–133, February, 1977.     

Effect of intravenous infusion of Polyosm on diuresis and parameters of systemic and cerebral hemodynamics

The effect of 30-min infusion of Polyosm (a polyethylene oxide 400 solution) is studied on anesthetized cats. The preparation stimulates diuresis and has no effect on arterial and venous pressure and cardiac and stroke indices. By the 30th min of infusion, the total peripheral and cerebral vascular resistance significantly decrease, while cerebral blood flow increases. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 123, No. 3, pp. 299–301, March, 1997     

Changes in hemodynamics and respiration in animals with different resistance to acute hypoxia

We studied the effects of acute hypoxia on hemodynamics and respiration in cats. The animals were divided into high-, low- and medium-resistant to hypoxia by the time of respiratory arrest after breathing with 3% O₂ gas mixture. In high-resistant animals, hemodynamic indices remained at a high level throughout the hypoxic episode, while in low-resistant cats they decreased shortly after the onset of hypoxia. It is suggested that the peculiarities of hemodynamic regulation play an important role in individual resistance to acute hypoxia. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 128, No. 9, pp. 286–290, September, 1999     

Changes in the histone/DNA ratio during the development of a multicellular organism

Changes in the histone/DNA ratio are studied in the star-fish. It is found that the development of a multicellular organism is based on the principle of nonequivalence of the sister cells which is described by the distribution of Polya. It is postulated that the development of an organism obeys the laws of mathematics. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 122, No. 12, pp. 695–698, December, 1996     

Relationship of changes in the central hemodynamics to the development of posthypoxic cerebral edema in the postresuscitation period

A syndrome of low cardiac output developed between the first and third hours after resuscitation in 16 dogs subjected to circulatory arrest for 15 min. In half of the cases its development was preceded by an increase in the cardiac output in the initial period of resuscitation. Without hyperperfusion at the beginning of resuscitation, the animals died 9–23 h after the beginning of the experiment. Among the surviving animals, edema of the cerebral cortex always developed in dogs with a reduced cardiac output 24 h after resuscitation, but no cerebral edema was observed in dogs with a high cardiac output.Laboratory of Experimental Physiology of Resuscitation, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR V. A. Negovskii.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 83, No. 3, pp. 266–268, March, 1977.     

Effects of arginine vasopressin on different cardiac arrhythmias

It was shown that arginine vasopressin positively affects the course of cardiac arrhythmias caused by aconitine, atropine, glypine, amphetamine, and ketamine, but not by calcium chloride. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 127, No. 3, pp. 272–274, March, 1999     

Inhibition of alcohol uptake in C57BI/6 mice by splenocytes extracorporeally stimulated with vasopressin

Experiments on C57BI/6 mice kept under conditions of free choice between alcohol and water for 4 and 12 months showed that adoptive transfer of splenocytes extracorporeally stimulated with arginine vasopressin suppressed alcohol intake. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 129, No. 6, pp. 617–619, June, 2000     

Two types of hemodynamic rearrangements in hypertensive patients during treatment with millimeter electromagnetic waves

Two types of hemodynamic rearrangements, due to a decrease in the stroke index and a decrease in the total peripheral vascular resistance, are revealed. As a result of treatment these rearrangements allow the systolic and diastolic arterial pressure to be corrected and enable the severity of clinical symptoms to be reduced along with the doses of administered drugs. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 118, N ^o 8, pp. 222–224, August, 1994 Presented by I. P. Ashmarin, Member of the Russian Academy of Medical Sciences     

Changes in the accessory group of hypothalamic neurosecretory cells after stimulation of the supraoptic nucleus

Changes in the accessory group of neurosecretory cells in cats were studied in acute experiments under chloralose anesthesia. Unilateral stimulation of the supraoptic nucleus, leading to vasoconstriction, caused activation of cells of the accessory group on the side of stimulation and an increase in size of the nucleolus. Cells of the paraventricular nucleus were unchanged whereas cells of the supraoptic nucleus were activated. The uniformity of response of the accessory group of neurosecretory cells and of the supraoptic nucleus, together with histochemical data in the literature, suggests that the two groups of cells produce vasopressin, some of which accumulates in the posterior lobe of the pituitary and some acts as a mediator outside the hypothalamus.Laboratory of Physiology of the Cerebral Circulation, A. L. Polenov Leningrad Neurosurgical Research Institute. (Presented by Academician V. N. Chernigovskii.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 83, No. 2, pp. 236–238, February, 1977.     

Contribution of the ventral structures of the medulla oblongata to the hemodynamics and transcapillary fluid exchange in the lungs

Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 116, N ^o 12, pp. 563–566, December, 1993     

Effect of electroacupuncture on systemic hemodynamics in rats with postinfarction cardiosclerosis

Electroacupuncture decreased total peripheral vascular resistance and increased cardiac output in 12-week-old postinfarction rats without cardiac insufficiency, while opposite changes were observed in rats with cardiac insufficiency. After the electroacupuncture course, norepinephrine decreased cardiac output in the rats with cardiac insufficiency, while acetylcholine increased it to a much higher extent than in the control rats that were not subjected to physiotherapy. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 127, No. 1, pp. 29–34, January, 1999     

Effects of calcium and its antagonists on hemodynamics and respiration

Acute tests on cats under Nembutal anesthesia show that intravenous injection of Ca²⁺ causes pathological respiration of the apneustic type and slight rises in pulmonary and arterial pressures. The calcium channel blockers verapamil and nifedipine decrease the amplitude of respiratory movements, increase the respiration rate and pulmonary pulse pressure, and lower systemic pressure. The introduction of verapamil or nifedipine into the fourth ventricle of the brain does not alter respiration or hemodynamics, whereas the introduction of Ca²⁺ leads to irreversible respiratory standstill. Hemodynamic parameters decrease 2–3 min after the respiratory standstill. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 122, No. 8, pp. 138–143, August, 1996