摘要:

BackgroundIndividuals with systolic-diastolic hypertension (SDH, systolic blood pressure (SBP) >160 mmHg and diastolic blood pressure (DBP) >90 mmHg) are at increased risk of thrombotic complications, such as stroke and heart attacks, which may be related to a hypercoagulable state. Individuals with only isolated systolic hypertension (ISH; i.e. SBP >160 mmHg but DBP<90 mmHg) are also at significant cardiovascular risk. We hypothesized that patients with ISH would exhibit a prothrombotic state similar to that seen in SDH. A secondary hypothesis was that individuals with ISH had similar echocardiographic parameters to those seen in SDH.MethodsWe measured indices of haemorheology, endothelial dysfunction, thrombogenesis and platelet activation in 23 individuals with ISH (mean blood pressure 193/82 mmHg), who were compared with 51 matched patients with SDH (mean blood pressure 198/112 mmHg) and 34 age- and sex- matched normotensive healthy control individuals (mean blood pressure 130/78 mmHg). Echocardiographic parameters in patients with ISH were compared to those from patients with SDH.ResultsMean plasma viscosity (an index of blood rheology, ANOVA,P= 0.001), von Willebrand factor (an index of endothelial damage,P= 0.013), plasminogen activator inhibitor-1 and lipoprotein (a) (both markers of thrombogenesis; Kruskal-Wallis test, bothP< 0.001) were all significantly raised in ISH and SDH relative to controls. Individuals with SDH also had high mean plasma fibrinogen (P= 0.018) and haematocrit (P= 0.010) levels compared with control individuals. There were no significant differences in levels of fibrin D-dimer or the platelet activation marker soluble P-selectin in the hypertensive patients (i.e. ISH and SDH) compared with control individuals. Patients with ISH had similar M-mode and Doppler echocardiographic parameters compared to patients with SDH.ConclusionsWe conclude that individuals with ISH have abnormalities in plasma prothrombotic factors and markers of endothelial dysfunction, and echocardiographic parameters, broadly similar to that seen in SDH. This is consistent with the increased risk of thrombotic events (strokes and heart attacks) in patients with ISH.

ISSN:0263-6352    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

ObjectiveTo determine whether antihypertensive treatment could alter hypertension and age-related progressive impairment of coronary hemodynamics and cardiac fibrosis in aged spontaneously hypertensive rats (SHR).DesignOld SHR were given their respective therapy for 3 months. To differentiate between hypertension and agerelated changes, a comparison was made between left and right ventricular indices since the right ventricle was not exposed to pressure overload.MethodsMale, 65-week-old spontaneously SHR were divided into three groups and were given either vehicle, felodipine (30 mg/kg per day) or enalapril (30 mg/kg per day). After 12 weeks of the respective treatments, systemic and coronary hemodynamics (radionuclide-labelled microspheres), right and left ventricular and aortic mass indices, and right and left ventricular hydroxyproline concentrations (an estimate of collagen) were determined.ResultsArterial pressure and total peripheral resistance were reduced to the same extent in SHRs treated with either felodipine or enalapril; however, compared to the control rats, enalapril was more effective in reducing left ventricular and aortic mass indices. Both agents also improved coronary hemodynamics of both ventricles in aged SHR but enalapril was more effective as indicated by a greater increase in coronary flow reserve and a greater decrease in minimal coronary vascular resistance. Furthermore, enalapril but not felodipine reduced left ventricular hydroxyproline concentration; and right ventricular hydroxyproline concentration increased with felodipine but remained unchanged with enalapril.ConclusionsBoth enalapril and felodipine ameliorated adverse cardiovascular effects of hypertension in the aged SHRs within 12 weeks, as demonstrated by reduced arterial pressure, diminished left ventricular mass, and improved coronary hemodynamics. Enalapril also decreased aortic mass and left ventricular collagen concentration and appeared to be more effective in improving coronary hemodynamics than felodipine, possibly as a result, in part, of reduced myocardial fibrosis.

ISSN:0263-6352    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

ObjectiveAlthough angiotensin-converting enzyme inhibitors are known to reduce albuminuria by preserving glomerular basement membrane anionic content, the effects of angiotensin II receptor blockage are currently not known. The aim of this study was to evaluate the effects of captopril and losartan on glomerular basement membrane anionic charges in a diabetic rat model.DesignAfter diabetes induction with streptozotocin, female Wistar rats were divided into three groups: group A, losartan 10 mg/kg by gavage (n= 8); group B, captopril 50 mg/l in drinking water (n= 6); group C, diabetic control rats (n= 8) given only tap water. Group D (eight rats) served as non-diabetic controls. At the end of 8 weeks, erythrocyte membrane charge, serum sialic acid, urinary glycosaminoglycan and albumin were measured and kidney specimens stained with Alcian blue in order to assess basement membrane glycosaminoglycans.ResultsRed blood cell anionic charges (ng Alcian blue/106red blood cells) were 371.5 ± 9.9 for group A, 443.5 ± 7.1 for group B, 400.1 ± 14.7 for group C, 468.7 ± 4 for group D (A < D, C < D,P< 0.01). Serum sialic acid levels (mg/dl) were 90.6 ± 14.1 for group A, 45.6 ± 6.8 for group B, 89.1 ± 8.5 for group C, 50.8 ± 6.4 for group D (A, C >D,P< 0.01; A >BP< 0.01). Albuminuria (μg/day) was 778 ± 221 for group A, 719 ± 314 for group B, 1724 ± 945 for group C, 393 ± 263 for group D (A, B < C,P< 0.05). Urinary glycosaminoglycan/creatinine ratio was 14.2 ± 1.1 for group A, 9.9 ± 1 for group B; 28.3 ± 8 for group C, 5.5 ± 1.7 for group D (B < C,P< 0.001; B < A,P< 0.003). Alcian blue staining was 1.8 ± 0.2, 2.2 ± 0.4, 1.5 ± 0.16, 2.8 ± 0.2 for groups A, B, C and D respectively (C, A < DP< 0.05).ConclusionLosartan and captopril have comparable effects on reducing albuminuria in a diabetic rat model. While captopril preserves basement membrane anionic charges, losartan has no effect. The anti-proteinuric effects of these drugs seem to have different mechanisms.

ISSN:0263-6352    

出版商:OVID    

年代:1999

数据来源: OVID

ISSN:0263-6352    

出版商:OVID    

年代:1999

数据来源: OVID

ISSN:0263-6352    

出版商:OVID    

年代:1999

数据来源: OVID

ISSN:0263-6352    

出版商:OVID    

年代:1999

数据来源: OVID