ISSN:0263-6352    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

Using an antibody to pure human renin and the technique of ultrastructural immunocytochemistry we have localized renin in the granular epithelioid cells of three juxtaglomerular apparatuses and one interlobular artery. The staining reaction of the cells was the same in both sites: we found that crystalline protogranules, rounded membranebound granules and storage granules intermediate in morphology all stained positively for renin. We also demonstrated immunoreactive renin in dilated cisternae of rough endoplasmic reticulum in the granular cells in both sites. We present these observations as morphological evidence that granular epithelioid cells synthesize and store renin both in the juxtaglomerular apparatus and in the larger arteries in the kidney.

ISSN:0263-6352    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

Trophic adrenergic influences may in part potentiate the pressure dependent development of structural cardiovascular changes in hypertension. Regression of such changes by antihypertensive treatment should therefore be most successful if adrenergic blocking drugs are used.In the present study spontaneously hypertensive rats (SHR) received either amethyldopa, metoprolol, felodipine, a new vasodilating Ca2+-antagonist, or metoprolol and felodipine in combination for 10 weeks. Their left ventricles were weighed and resistance vessel design was analysed using a haemodynamic technique.Arterial pressure (MAP) was equally reduced by metoprolol and felodipine. Despite their different modes of action cardiovascular design was also equally affected. The combined regimen reduced average MAP more than either drug alone. It also caused more pronounced regression of cardiovascular structural changes. Methyldopa lowered MAP less than either metoprolol or felodipine and had only modest effects on cardiovascular design. Thus, the extent of MAP reduction, regardless of which therapeutic regimen is used to induce it, determines the extent of regression of structural cardiovascular changes during antihypertensive treatment.

ISSN:0263-6352    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

The relationship between serum autoantibodies and vascular events was investigated in 140 patients with essential hypertension during a five-year period. The influence of time upon incidence of autoantibodies was assessed in 55 normotensive controls of roughly the same distribution of age and sex. Thirty-four patients experienced a vascular event, which was fatal in 10 cases (7.1%). Eight of these 10 patients had autoantibodies in serum before the events, and the presence of autoantibodies at entry to the study tripled the five-year relative risk for vascular events. Antinuclear antibodies (ANA) and smooth muscle antibodies (SMA) especially contributed to this increased risk. The vascular events were followed by a significantly increased occurrence of ANA. In the control subjects no events occurred and no significant increases in the presence of autoantibodies were found during the five years. ANA and SMA positive sera showed no significant complement fixing properties, and the autoantibodies studied seemed to be secondary to tissue damage. Despite this, they seemed to reflect an ongoing injury of the vascular bed.

ISSN:0263-6352    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

Compared with white normal males without a family history of hypertension (n=43), red blood cells of white normal males with such a family history (n=17) had a higher (P<0.01) intracellular sodium concentration (8.07 ± 0.30 versus 7.33 ± 0.17 mmol/l cells). This could be at least partly due to their lower (P<0.001) frusemide-sensitive sodium efflux rate (250 ± 19 versus 424 ± 23 µmol/l cells/h). Also their ouabain-resistant 86Rb-uptake (0.81 ± 0.06 versus 0.97 ± 0.03 µmol/l cells/h) was lower (P<0.05). Potassium concentration in the red blood cells was similar in both groups.

ISSN:0263-6352    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

Vascular prostacyclin production in Goldblatt hypertension was examined in one-kidney, one clip (1K,1C) and two-kidney, one clip (2K,1C) rat models. Vasodepressor responses to prostacyclin and nitroprusside correlated well with resting blood pressure in both groups of rats, but when measured as a percentage of resting blood pressure the responses did not differ significantly between hypertensive rats and the normotensive controls within each group. In contrast, the vasodepressor effects of arachidonic acid (1-3 mg/kg, i.v.) were much greater in the 1K,1C rats than in their normotensive controls, but did not differ significantly between hypertensive 2K,1C rats and sham-operated controls. The effects of arachidonic acid were virtually abolished by indomethacin (10 mg/kg, i.v.). The metabolism of [14C]-arachidonic acid was also studied in isolated aortae of both one- and two-kidney rats by high pressure liquid chromatography of extracts of the incubation mixture. [14C]-6-oxo-PGF1α was the only prostanoid conversion product recovered from the incubations and significantly more of this metabolite was produced by aortic tissue from 1K,1C rats than from normotensive controls. There was no difference in [14C]-6-oxo-PGF2 α production between 2K,1C rats and controls. These results demonstrate an enhanced ability of vascular tissue from 1K,1C hypertensive rats to convert exogenous arachidonate to vasodilator prostacyclin, but this is not evident in the two-kidney model. Although enhanced biosynthetic capacity for prostacyclin in the one-kidney model and spontaneously hypertensive rats does not lessen peripheral vascular resistance, it might reflect a fundamental disturbance in phospholipid metabolism which contributes to increased vascular resistance.

ISSN:0263-6352    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

Central (six patients) and brachial (12 patients) haemodynamics were studied in men with sustained essential hypertension before and after intravenous administration of an alpha post-synaptic adrenergic blocking drug, urapidil. Brachial arterial compliance was evaluated non-invasively from the simultaneous measurement of pulse wave velocity and arterial diameter. In basal conditions, arterial compliance was reduced in hypertensives. Urapidil caused a significant drop in blood pressure, due to a significant decrease in total peripheral resistance with no change in cardiac output and heart rate. Brachial arterial diameter and compliance did not change significantly. The results show that the decreased arterial compliance in hypertensive patients was not due exclusively to the elevation of blood pressure or to a predominant activation of the autonomic nervous system, or both. Such observations suggest that, in men with sustained essential hypertension, the decreased compliance was probably related to structural alterations of large arteries.

ISSN:0263-6352    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

We assessed the effects on renal haemodynamics in 18 black patients with essential hypertension of acute and chronic β-adrenergic blockade with three agents having different properties: atenolol, nadolol or propranolol. Six patients received each drug. In our patients the antihypertensive response to β-blockers was minimal or nonexistent. This permitted us to analyse the effects on renal haemodynamics of 'pure' β-blockade, as opposed to the combined effects of β-blockade and decreased systemic perfusion pressure. In this setting, neither acute nor chronic administration (two months) of each of these agents decreased renal perfusion. We conclude, therefore, that β-blockade per se has no deleterious effect on renal function and previous observations are most probably accounted for by the blood pressure lowering effect of these drugs, either alone or coupled with β-blockade of the renal vasculature allowing unopposed α-sympathetically mediated vasoconstriction.

ISSN:0263-6352    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

DOCA-salt hypertension was produced in 10 male 10-week-old normotensive Wistar- Kyoto (WKY) rats receiving deoxycorticosterone acetate (DOCA; 100mg/kg, subcutaneous pellet) and 1% NaCI drinking water and was compared with data from 10 age- and sex-matched WKY receiving normal tap water (C). These data were also compared with spontaneously hypertensive (SHR) rats similarly treated. After 10 weeks on these programmes, systemic and regional haemodynamics were determined in conscious rats using microsphere techniques. DOCA-salt treatment increased mean arterial pressure (MAP), total peripheral resistance index (TPRI), cardiac and renal weights in both WKY and SHR. In contrast to SHR (C), the SHR (DOCA) demonstrated more severe MAP elevation (204 ± 4 versus 185 ± mmHg; P<0.01), more severe systemic and regional (especially renal) vasoconstriction, and malignant vasculitis associated with azotaemia and hyperuricaemia. The hyperuricaemia was related inversely to renal blood flow(r=-0.74; P<0.01) and directly to renal vasoconstriction (r=0.65; P<0.05) in SHR (DOCA). These data suggest that in both WKY and SHR, DOCA and salt produced marked cardiovascular changes and SHR rats developed malignant hypertension.

ISSN:0263-6352    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

In order to determine factors contributing to sodium induced changes of blood pressure, 20 patients with essential hypertension were studied when on their regular sodium intake and after two weeks of a low sodium diet (50 mmol daily) and two weeks of a high sodium diet (300 mmol daily). There were two periods of regular sodium intake, one of four weeks at the beginning and one of two weeks at the end of the study. The change in mean arterial pressure between the high and low salt diets (δMAP) was regarded as a measure of sodium sensitivity, and was directly correlated with age and initial blood pressure. Compared with non-responders, responders (δMAP 10 mmHg or more) showed a lesser activation of the renin-angiotensin-aldosterone system during the low salt period.The response to the administration of intravenous frusemide was not helpful in predicting sodium sensitivity. A significant but relatively small (4.2 mmHg) reduction in MAP was obtained during low salt period compared with the first period of regular sodium intake. The data suggest that moderate dietary sodium restriction can help to reduce the blood pressure of the relatively older patient with hypertension.

ISSN:0263-6352    

出版商:OVID    

年代:1984

数据来源: OVID