Decrease In Cerebral Vascular Resistance Research Articles

Circulatory effect of cigarette smoking, with special reference to the effect on cerebral hemodynamics.

The circulatory effect of cigarette smoking on cerebral hemodynamics, blood pressure and pulse rate were investigated in four normal young men and eight elderly patients with mild diseases, all habitual tobacco smokers (10-20 cigarettes daily). (1) Decrease in cerebral vascular resistance (dilatation of cerebral blood vessel) and increase in cerebral blood flow were observed in all subjects with the ordinary smoking. On the other hand, blood pressure and pulse rate did not change or slightly increased. (2) A conspicuous increase in cerebral hemodynamic, blood pressure and pulse rate were observed in the elderly subjects with rapid smoking. (3) It is suggested that the cerebral circulatory effect of tobacco smoking is mainly due to the direct effect of nicotine, since a significant correlation is not observed between cerebral hemodynamic and blood pressure with ordinary smoking.

The determinants of cerebrospinal fluid Po2. The effects of oxygen and carbon dioxide breathing in patients with chronic lung disease.

Excerpt While hypoxia and hypercapnia usually cause a decrease in cerebral vascular resistance, cerebral oxygen consumption is little changed except under extreme conditions. The effect of these ch...

Cerebral circulatory effects of acutely induced hypervolemia in human subjects.

Expansion of the blood volume with 5 per cent albumin solution was associated with a 32 per cent increase in cerebral blood flow and a commensurate decrease in cerebral vascular resistance. Expansion of the intravascular volume with whole blood was not associated with any consistent cerebral hemodynamic alteration. It is suggested that the response of the cerebral circulation was largely governed by the factitious "anemia" induced by the selective expansion of the plasma volume.

The effect of niacinamide on cerebral circulation.

SummaryNiacinamide in large doses (3-5 g) administered intravenously increased significantly cerebral blood flow and cerebral oxygen consumption, but decreased mean arterial blood pressure and cerebral vascular resistance in dogs. This drug in small doses had no such effects. The increase in cerebral blood flow was attributed to an increase in cardiac output associated with a decrease in cerebral vascular resistance.

Effects of vigorous physical exercise on cerebral circulation and metabolism

1. 1. The effects of vigorous muscular exercise in the upright posture were studied in thirteen normal subjects and compared with the changes resulting from motionless standing. 2. 2. Exercise resulted in a decrease in cerebral vascular resistance and an increase in cerebral oxygen consumption. The decrease in mean cerebral blood flow which results from motionless standing did not occur with exercise. There was no change in cerebral respiratory quotient. 3. 3. Although exercise resulted in a striking fall in blood carbon dioxide content and pH, no correlations could be made between these changes and the alterations in cerebral circulatory or metabolic functions. There was a close correlation between changes in cerebral vascular resistance and cerebral oxygen consumption, though the reason for this is not known.

The cerebral effects of papaverine hydrochloride in toxemia of pregnancy

1.1. With the use of the nitrous oxide method of Kety and Schmidt, the cerebral blood flow and related circulatory and metabolic functions of the brain were studied both before and after the administration of papaverine hydrochloride to a group of women with pre-eclampsia and hypertensive toxemia of pregnancy.2.2. No untoward effects were caused by this drug.3.3. Papaverine hydrochloride brought about the following changes in the nonconvulsive toxemias of pregnancy: 3.1.a. Significant lowering of mean arterial blood pressure.3.2.b. Significant and rapid decrease of cerebral vascular resistance to normal.3.3.c. Significant increase of cerebral blood flow.3.4.d. Significant increase in the oxygen utilization by the brain.4.4. The possible value of this drug in toxemia of pregnancy is discussed and it is concluded that it should be given a thorough clinical trial as an adjunct to the therapy of this disease.