Effect of Captopril on Antithrombus Function of Endothelium

ＥｆｆｅｃｔｏｆＣａｐｔｏｐｒｉｌｏｎＡｎｔｉｔｈｒｏｍｂｕｓＦｕｎｃｔｉｏｎｏｆＥｎｄｏｔｈｅｌｉｕｍＸＩＯＮＧＹｉ－ｌｉ（熊一力）；ＺＨＡＯＨｕａ－ｙｕｅ（赵华月）（ＤｅｐａｒｔｍｅｎｔｏｆＭｅｄｉｃｉｎｅ，ＴｏｎｇｊｉＨｏｓｐｉｔａｌ，Ｔｏｎｇ...     

Captopril and time dependent changes in post- to pre-glomerular resistance ratios in remnant kidneys of pre-hypertensive rats

Wilke , W. Lee & Person , A. E. G. 1992. Captopril and time dependent changes in post- to pre-glomerular resistance ratios in remnant kidneys of pre-hypertensive rats. Acta Physiol Scand 144 , 253–261. Received 26 June 1991, accepted 8 October 1991. ISSN 0001–6772. Department of Physiology, Colorado State University, Fort Collins, Colorado, USA and Department of Physiology and Biophysics, University of Lund, Sweden. Micropuncture experiments were performed on intact and remnant kidneys of male Sprague-Dawley rats before and after angiotensin converting enzyme inhibition with captopril (0.5 mg kg^-1 iv). Partially nephrectomized rats were studied at 2 and 8 weeks post-surgery before the development of systemic hypertension. At 2 weeks, nephrectomized rats had a numerically higher tubular stop-flow pressure than controls (43 ± 2 mmHg vs. 38 ± 2 mmHg; P = 0.08) and a higher post- to pre-glomerular resistance ratio (Re/Ra) (0.40 ± 0.03 vs. 0.31± 0.03; P = 0.08). At 8 weeks, stop-flow pressure and post- to pre-glomerular resistance ratios were similar in remnant and intact kidneys. Captopril had no effect on stop-flow pressure in 2 week post-surgery nephrectomized rats or either control group, but it increased stop-flow pressure in 8 week post-surgery nephrectomized rats (40 ± 2 to 44 ± 2 mmHg, P= 0.04). This increase in stop-flow pressure was associated with an increase in the post- to pre-glomerular resistance ratio (0.33 ± 0.02–0.42 ±0.02, P = 0.009). Stop-flow pressure was positively correlated with the post- to pre-glomerular resistance ratio in 2-week post-surgery nephrectomized rats and their respective controls when combined (r = 0.89, P= 0.0001) and 8-week post-surgery nephrectomized rats and their respective controls combined (r= 0.78, P = 0.0001). Stop-flow pressure was not significantly correlated with mean arterial pressures or welling-point pressures in these groups. We conclude that stop-flow pressure in remnant kidneys of pre-hypertensive rats is primarily determined by the post- to pre-glomerular resistance ratio, and increases in stop-flow pressure and post- to pre-glomerular resistance ratios in remnant kidneys are transient in the absence of systemic hypertension. The role of the renin-angiotensin system in determining the ratio and stop-flow pressure is dependent on time post-nephrectomy. Captopril-induced increases in stop-flow pressure and post- to pre-glomerular resistance ratio at 8 weeks, suggests that its primary effect at that time is not a preferential post-gIomerular vasodilation subsequent to reductions in intrarenal angiotensin II.     

复方卡托普利片中氢氯噻嗪的含量及均匀度测定

用紫外分光度法直接溯定复方卡托普利片中氢氯噻嗪的含量及均匀度。测定波长为272±1nm,平均回收率100.2%,变异系数0.3%,吸收度与氢氯噻嗪的浓度在1～10μg/ml 范围内具有线性关系。     

Deleterious effect of exogenous angiotensin-I on the extent of regional ischaemia and its inhibition by captopril

The endogenous activity of the local renin-angiotensin system(RAS) and the anti-ischaemic properties of captopril were investigatedin electrically driven rabbit Langendorff hearts (constant pressure:70 cmH₂O, Tyrode solution, Ca²⁺ 1.8 mmol.l^–1). Cumulativeconcentration-response curves showed no significant difference(P>0.05) between the reduction of the global coronary flow(CF) by exogenous angiotensin-I or angiotensin-II (EC₅₀ = 10^–10mol.l^–1). It is concluded that the local RAS in isolatedrabbit hearts is highly sensitive, whereas its endogenous activityis very low due to very low endogenous angiotensin-I content.Myocardial ischaemia (MI) was induced by the occlusion of aleft coronary artery branch and MI was quantified from NADHsurface fluorescence photography. MI was significantly enlarged(+35%) (P <0.05) by exogenous angiotensin-I (6x10^–9mol.l^–1). The reduction in CF and the increment in MIby angiotensin-I could be completely prevented by adding captoprilat a low concentration (10^–6 mol.l^–1) to the perfusionbuffer. In the absence of exogenous angiotensin-I, captoprilalone (10^–6 mol.l^–1) neither significantly enhancedCF (P >0.05), nor diminished MI (P >0.05), supportingthe finding of very low endogenous activity of tile local RASin this model. We, moreover, conclude that at a low concentration(10^–6 mol.l^–1) captopril does not possess directcardioprotective properties independent of its ACE inhibitingaction.     

Influence of a single dose of captopril on pulmonary haemodynamics and right ventricular function in mitral stenosis with pulmonary hypertension

Summary The response of the pulmonary circulation to captopril 75 mg has been examined in 21 patients with pulmonary hypertension secondary to mitral stenosis. The effects of captopril were measured every 15 min up to 2 h by recording pressures in the pulmonary and systemic circulations and by measuring cardiac output.Pulmonary artery systolic pressure fell significantly by 21.6% (from to 42.8 mm Hg), pulmonary artery diastolic pressure by 23.3% (from 26.2 to 20.1 mm Hg), and the pulmonary artery mean pressure by 23.2% (from 36.9 to 28.3 mm Hg). Right ventricular end-diastolic pressure also fell significantly by 7% (8.1 to 7.5 mm Hg). Heart rate decreased by 6.5% (from 76.3 to 71.3 beats·min^–1). Cardiac index and stroke volume index did not change. The total and vascular pulmonary resistance dropped significantly by 23.2% (from 721 to 553.7 dyn·s·cm^–5) and 40% (from 287.2 to 172 dyn·s·cm^–5), respectively. The right ventricular stroke work index fell by 33% (from 15.1 to 10.1 g/beat/m²). Systemic systolic pressure decreased by 10.5% (from 124.5 to 111.4 mm Hg). Thus, captopril lowered pulmonary pressures and resistances and no deterioration in right ventricular function was observed.     

Is captopril effective in controlling blood pressure when administered once daily? An assessment using 24-h ambulatory blood pressure monitoring

Summary Twelve patients with essential hypertension receiving captopril monotherapy or captopril in conjunction with a diuretic had their 24-h blood pressure profiles monitored using an automatic, non-invasive ambulatory method. The study examined the efficacy of once a day versus twice a day administration of the ACE inhibitor in controlling blood pressure.Six untreated subjects with borderline hypertension were also studied using the same monitoring equipment and with the same frequency, to act as controls because of the possibility of repeated use of the device causing a familiarisation effect.The results obtained indicated that if anything, the once daily dosing produced marginally better blood pressure values. The amplitude of the diurnal blood pressure variation was reduced on a second-wearing of the monitoring equipment suggesting some degree of familiarisation with the apparatus.     

川芎嗪、山莨菪碱、蝮蛇抗栓酶及卡托普利对糖尿病大鼠肾脏的保护作用

目的　探讨川芎嗪、山莨菪碱、蝮蛇抗栓酶及卡托普利对实验大鼠糖尿病肾病 (DN)的预防作用。方法　SD大鼠 6 0只 ,分为正常对照组、糖尿病组及各糖尿病治疗组。以四氧嘧啶腹腔内注射制成糖尿病模型。各治疗组分别给予上述药物治疗 ,每周 5次 ,共 14周。取肾脏行光镜和电镜检查 ,并进行图像分析 ,同时测定蛋白糖基化产物 (GP)。结果　与糖尿病组比较 ,各治疗组肾组织中水平明显降低 (P <0 .0 1) ;除蝮蛇抗栓酶组外 ,其他治疗组大鼠肾小球截面积亦明显缩小 (P <0 .0 5 ) ;糖尿病组大鼠肾小球基底膜显著不均匀增厚 ,而各治疗组病变较轻 ,尤以卡托普利组疗效最为明显。结论　改善微循环、血液流变学及血流动力学治疗可减慢实验大鼠DN的进展。     

巯甲丙脯酸用于流行性出血热治疗临床观察

目的观察巯甲丙脯酸用于流行性出血热治疗的临床效果。方法病人随机分为A、B、C3组,A组在进入少尿期口服巯甲丙脯酸25mg,日3次;B组在少尿期并发高血压时开始服用,剂量方法同A组。C组在少尿期并发高血压时口服复方降压片1～2片,每日3次。其他治疗相同。结果A组无1例发生高血压;B组用药后4～6小时血压开始下降,72小时后血压稳定且正常。C组血压偏高。A、B组肾功能恢复快,并发症少,病程短。结论巯甲丙脯酸用于治疗流行性出血热可减少或防止急性肾功能衰竭,减少并发症。     

ACEI对去卵巢骨质疏松大鼠激肽释放酶-激肽系统及骨丢失的影响

目的探究血管紧张素转换酶抑制剂(angiotensin-converting enzyme inhibitor,ACEI)卡托普利对去卵巢(OVX)骨质疏松大鼠骨丢失及激肽释放酶-激肽(kallikrein-kinin system,KKS)系统的影响。方法去卵巢法制备绝经骨质疏松大鼠模型,分为OVX组、ACEI组[6 mg/(kg·d)卡托普利]、阳性对照雌激素组[0.05 mg/(kg·d)己烯雌酚],另不去卵巢为Sham组。给药8周后,全自动生化分析仪检测血清钙(Ca)、Ⅰ型前胶原N-端肽(PINP)、碱性磷酸酶(ALP)、骨钙素(OCN)、抗酒石酸酸性磷酸酶(TRAP)及Ⅰ型胶原交联C端肽β序列(β-CTX)水平,微型计算机断层摄影术(micro CT)法检测骨密度及微结构,TRAP法观察骨组织破骨细胞数量,Western blot法检测骨组织中骨形态发生蛋白2(BMP2)、Runt相关转录因子2(Runx2)、组织激肽释放酶(KLK)、缓激肽受体1(B1R)及缓激肽(BK)蛋白表达。结果相较于Sham组,OVX组大鼠骨密度、骨小梁数量及厚度、骨体积分数、SMI、PINP、ALP、OCN水平、BMP2、Runx2蛋白表达均降低(P均0.05),骨小梁分离度、TRAP、β-CTX水平、破骨细胞数量、KLK、B1R及BK蛋白水平均增加(P均0.05)。相较于OVX组,ACEI组、阳性组大鼠骨密度、骨小梁数量及厚度、骨体积分数、SMI、PINP、ALP、OCN水平、BMP2、Runx2蛋白表达均增加,骨小梁分离度、TRAP、β-CTX水平、破骨细胞数量、KLK、B1R及BK蛋白水平降低(P0.05)。结论 ACEI可抑制KKS系统,降低破骨细胞活性减少骨吸收,增强成骨细胞活性增加骨形成,提高骨密度,改善骨微结构,进而改善OVX大鼠骨质疏松症状。