摘要:

The antihypertensive response to nicardipine was analyzed in 467 hypertensive patients who had participated in four similarly designed double-blind clinical studies in which the effectiveness of nicardipine was evaluated. This population was divided into five age groups. The difference in response rates between the youngest (≤39 years) and oldest group (≥70 years) of patients was less than 5%. After 12 weeks of treatment with nicardipine, the rate of response for each decade ranged from 65% to 77%. The per cent decrease in blood pressure was not age dependent, but did correlate with the pretreatment systolic and diastolic blood pressure (P< 0.001). No age-related trend in side effects was observed. The incidence of side effects ranged between 0% among the oldest patients to 17.3% in patients 50–59 years of age. No adverse metabolic effects were found in any age groups. These results indicate that nicardipine, a calcium entry-blocker, is effective and useful in adult hypertensive patients of all ages.

ISSN:0263-6352    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

We investigated the effects of intracerebroventricular infusions of endothelin on cardiovascular and endocrinological responses using conscious, unrestrained rats. Chronic intracerebroventricular infusions of endothelin, 10 pmol/h for 7 days, elevated arterial pressure significantly on days 5, 6 and 7 of the infusion, compared with intracerebroventricular infusions of the vehicle. Heart rate decreased from day 1 of the infusion of endothelin until the end of the experiment. The urinary excretion of norepinephrine increased on day 3 and epinephrine increased on days 3, 4 and 5 of endothelin infusion. The urinary excretion of arginine vasopressin increased on day 5, 6 and 7 of the infusion. These findings suggest that chronic intracerebroventricular infusions of endothelin elicit elevations in arterial pressure and that the initiation of blood pressure rises can be related to sympathetic activation although the actual role for the pressor responses has been played by the released arginine vasopressin.

ISSN:0263-6352    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Of 691 healthy (untreated) villagers of Tecumseh, Michigan (average age 32.6 years), 99 had a clinical blood pressure exceeding 140/90 mmHg. Thirty-seven per cent of these borderline hypertensives had increased heart rate, cardiac index, forearm blood flow and plasma norepinephrine. These subjects had elevated self-determined home blood pressure (average of 14 measurements). The present hyperkinetic borderlines had elevated blood pressure at 5, 8, 21 and 23 years of age and their parents also had higher blood pressure. The prevalence of high blood pressure in Tecumseh, its long history, elevated blood pressure readings outside the physician's office and family background of hypertension, suggests that the hyperkinetic state is a significant clinical condition. Previous studies on hospital-based populations proved that the hyperkinetic state is caused by an excessive autonomic drive. The association of the hyperkinetic state with elevated norepinephrine in this study suggests that a sympathetic hyperactivity is present in a large proportion of unselected subjects with mild blood pressure elevation.

ISSN:0263-6352    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

The involvement of an auto-immune mechanism has been suggested in the development and/or the maintenance of hypertension in male, genetically hypertensive rats of the Lyon strain (LH). The aim of this study was to determine whether hypertension may be transferred, by lymphoid cells, from hypertensive donors to male, normotensive rats of the Lyon strain (LN). Experiments designed to induce a resistance to hypertension in LH rats by transfer of lymphoid cells from LN animals were also performed. Since LH and LN are mismatched at the major histocompatibility complex, transfers of fetal liver cells (FLC from fetuses of 13–14 days gestation were performed. These experiments demonstrate the ability of FLC to allow a prolonged survival (over 17 weeks) without graft versus host disease in the rat. As regards the blood pressure level, no LN recipient having received FLC from LH donor became hypertensive, thus showing that hypertension cannot be transferred by lymphoid cells in normotensive animals. Resistance to hypertension was so weakly transferred to hypertensive rats (results being significantly different only at 10 weeks post-grafting) that it may be considered doubtful.

ISSN:0263-6352    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

We evaluated the effects of an increased serum potassium level, the result of a potassium infusion, on the pressor response to infused calcium in normotensive men. Potassium infusion (0.38 mmol/kg per h for 2 h) increased serum potassium by 1.1 mmol/l with no changes in blood pressure, cardiac output or total peripheral vascular resistance (n = 6). Calcium infusion (0.19 mmol/kg per h for 1 h) and combined infusion of potassium followed by calcium increased serum calcium by 1.1 mmol/l with an elevated blood pressure, vascular resistance and no change in cardiac output (n = 8). The absolute and per cent increases in blood pressure and vascular resistance during the calcium infusion did not differ in the absence compared with in the presence of an increased serum potassium. These results indicate that a small increase in serum potassium did not modify the pressor response to infused calcium. We conclude that hypercalcaemia-induced hypertension is caused by direct effects of calcium on arterial smooth muscle.

ISSN:0263-6352    

出版商:OVID    

年代:1991

数据来源: OVID