摘要:

10-7mol/l) caused the partially relaxed vessels to contract again. Indomethacin enhanced relaxation in the 12-week-old SHR and reduced the difference between the SHR and WKY. The reduction in acetylcholine-induced, endothelium-dependent relaxation in SHR suggested that a functional change occurred, causing the vessels to release a vasoconstrictor factor that opposes the action of endothelium-derived relaxing factor.

ISSN:0263-6352    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

Na+transport kinetics were studied in red blood cells (RBCs) from 50 essential hypertensive patients and 30 normotensive controls. Seven hypertensive patients were characterized by the following: (1) a maximal rate of Na+-Li+countertransport higher than an upper normal limit of 525 (imol. litre cells-1. h-1; (2) an apparent dissociation constant for internal Na+higher than an upper normal limit of 20.4 mmol. litre cells (in only five of the seven hypertensives); (3) no other kinetic abnormality in Na+,K+pump, Na+,K+cotransport or passive Na+permeability. Clinically, hypertensives with abnormal countertransport were characterized by high serum low-density lipoprotein (LDL) cholesterol levels and the presence of electrocardiographic left ventricular hypertrophy (LVH). Conversely, mean values of these two clinical parameters were normal in the remaining hypertensive patients, independently of the presence of other abnormalities in Na+,K+pump, Na+,K+cotransport or passive Na+permeability. In conclusion, the presence of abnormal Na+-Li+countertransport kinetics in erythrocytes may be associated with an enhanced cardiovascular risk in hypertension.

ISSN:0263-6352    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

Administration of atriopeptin III (125, 250 and 500ng/kg, intravenously) into pentobarbitone anaesthetized normotensive and DOCA-salt hypertensive rats had no effect on blood pressure or renal haemodynamics. Urine flow and absolute and fractional sodium excretion were increased by 48–90% from the lowest to the highest dose of atriopeptin III in the normotensive group, but were increased by over twice these amounts in the DOCA-salt hypertensive rats. Fractional lithium excretion and calculated proximal tubular fluid reabsorption were unaffected by the peptide in the normotensive rats, but in the hypertensive group atriopeptide III increased fractional lithium excretion by 25–50% and decreased proximal tubular reabsorption to a similar extent. Beyond the proximal tubule there were similar increases in fractional and absolute fluid handling in both groups of rats. These results demonstrated that in DOCA-salt hypertension there was increased sensitivity to the natriuretic activity of atriopeptin III which appeared to result from an increased responsiveness of the proximal tubule.

ISSN:0263-6352    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

The development of a novel model of human alcoholism has involved the presentation of a 30% alcohol solution to Sprague–Dawley rats via a syringe-feeding needle apparatus. With twice daily intermittent drinking, rats consumed an equivalent of 7–8g/kg body weight of alcohol, which represented 25% of total daily caloric intake. Alcohol was absorbed rapidly, as significant circulating concentrations were observed within 15min of gavage, eventually peaking at approximately 200 mg% 1 h later. Hemodynamic recordings in the conscious state after a 10-week drinking program indicated a normotensive blood pressure at peak blood alcohol levels, yet a hypertensive response 24 h after the final drink at a time when blood alcohol was not detected. Alcoholic rats continued to gain weight in parallel with controls fedad libitumthroughout the study, and changes in cardiac size and indices of contractility were not affected by 10 weeks of intermittent drinking. Additionally, no histological evidence of cardiac muscle damage was observed in alcoholic animals. Our animal model closely resembles the clinical situation in terms of the pattern of alcohol consumption, circulating concentrations of alcohol and the percentage of caloric intake in the form of alcohol. The hemodynamic changes observed support the hypothesis that alcoholic hypertension may be a manifestation of withdrawal, as opposed to any direct pressor effect of alcohol itself.

ISSN:0263-6352    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

The present guidelines were prepared by the Guidelines Sub-Committee† of the WHO/ISH Mild Hypertension Liaison Committee. They represent the second revision of the WHO-ISH guidelines and were finalized after presentation and discussion at the 5th Mild Hypertension Conference held in Melbourne, Australia on 4–7 December 1988. The guidelines will be revised again at the time of the 6th Meeting.

ISSN:0263-6352    

出版商:OVID    

年代:1989

数据来源: OVID