摘要:

SUMMARY1. Studies in sheep have led to the concept of a ‘hypertensinogenic’ (HT) steroid hormone activity, whereby the blood pressure (BP) raising effects of adrenocortical steroids can be separated from theirin vivoglucocorticoid (GC) or mineralocorticoid (MC) activities.2. The three main lines of evidence are as follows: (i) BP raising effects of ACTH cannot be reproduced by appropriate rates of infusion of steroids with GC and MC activities; (ii) certain steroids e.g. 9α‐fluorocortisol can increase BP at rates of infusion below threshold forin vivoGC or MC actions and for many steroids there is no correlation between GC, MC and HT effects; (iii) demonstration of differential antagonism of HT, MC and GC effects.3. Studies in man show that the BP effects of ACTH are due to cortisol (F) at levels which have both MC and GC activity. However, BP effects of ACTH cannot be blocked by MC and GC antagonists.4. Although complete separation ofin vivoGC, MC and HT activities has not been possible in man, our own studies show a degree of dissociation. Taken together, these data suggest that steroids may raise BP by a HT mechanism distinct from classicalin vivoMC or GC activities in man as well as

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1990.tb01299.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

SUMMARY1. Two patients with angiotensin‐responsive aldosterone‐producing adenoma (APA) and one with adrenal cortical carcinoma demonstrated autonomous secretion of cortisol as well as of aldosterone.2. The response of cortisol and of aldosterone to ACTH did not differentiate between the two APA which secreted cortisol and the eight which demonstrated normal suppression with dexamethasone.3. Concurrent autonomous secretion of cortisol as well as aldosterone may occur in patients who present clinically with primary aldosteronism.4. Biochemical distinctions between adenomas may reflect differences in their cellular composit

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1990.tb01300.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

SUMMARY1. Calcium was infused in normal subjects in subpressor dosage to examine the effects of raised calcium levels on atrial natriuretic peptide (ANP) concentrations.2. Calcium infusion progressively raised serum ionized and total calcium concentrations significantly, without raising mean arterial pressure or heart rate.3. Plasma ANP concentrations increased significantly by 5 min of infusion and increased further by 15 min (approximately 40%) to levels which were maintained to 60 min.4. Urinary sodium excretion increased by 140% during calcium infusion.5. Calcium may affect secretory as well as contractile functions of the atrial myocyte.

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1990.tb01301.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

SUMMARY1. Adrenergic mechanisms play an important role in regulation of ACTH release. We used the α2‐adrenergic agonist, clonidine, as a central nervous system inhibitor of ACTH release to see if it would alter naloxone‐induced ACTH secretion in normal human volunteers.2. There was a significant blunting of the mean peak level of ACTH and the mean peak change of ACTH from basal as well as the area under the ACTH‐time curve when clonidine was given prior to naloxone.3. We conclude that clonidine, by blocking central noradrenergic pathways, which stimulate corticotropin‐releasing hormone secretion, inhibits naloxone‐induced ACTH secretion. This suggests that naloxone causes ACTH release through these same central noradrenergi

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1990.tb01302.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

SUMMARY1. A 17 year old female presented with severe hypertension, hypokalaemia and elevated levels of plasma renin activity due to a renin‐secreting tumour.2. Renin was responsive to posture, low sodium diet, saline infusion and frusemide, but relatively unresponsive to raising or lowering circulating levels of angiotensin II.3. Renal venous renin levels lateralized to the side of the tumour with good contralateral suppression when measured with control of posture and avoidance of prior stimulation, with and without angiotensin converting enzyme inhibition.4. Levels of atrial natriuretic peptide were elevated and responsive to posture, saline infusion and angiotensin infusion.5. The tumour was evident on computerized tomography, but not on intravenous pyelography or renal angiography.6. Responsiveness of renin secretion to normal stimuli in reninoma may make diagnosis difficult, and renal vein sampling under controlled conditions is necessar

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1990.tb01303.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

SUMMARY1. Plasma potassium and chloride concentrations were raised and plasma renin activity, aldosterone, bicarbonate and arterial pH were reduced in two brothers with the syndrome of hypertension and hyperkalaemia with normal glomerular filtration rate (Gordon's syndrome), on unrestricted or moderately restricted sodium diets.2. These abnormalities were corrected in both patients within 10 days of severe sodium restriction.3. Pressor sensitivity to cold and angiotensin II decreased on low sodium diet, associated with a fall in blood pressure.4. Increasing distal tubular sodium delivery by infusion of normal saline increased fractional excretion of potassium when aldosterone had been stimulated by severely restricted sodium diet, but not when aldosterone levels were low on unrestricted sodium diet.5. These findings are consistent with excessive sodium reabsorption as the primary renal lesion in Gordon's syndrome, leading to volume expansion and suppression of renin and aldosterone. Severe dietary sodium restriction leading to volume contraction, by stimulating renin and aldosterone and promoting kaliuresis, corrects the abnormalities.

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1990.tb01304.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

SUMMARY1. Diets used to reduce sodium intake often involve changes in fats and fibre which might themselves affect blood pressure and/or lipid metabolism. To evaluate the relative importance of these dietary changes for the management of hypertension we have studied the independent and additive effects of sodium restriction (60 mmol/day) and a low fat (30% energy), high P/S ratio (1.0), high fibre (30–50 g/day) ‘cholesterol lowering’ diet.2. Ninety‐five hypertensives entered a four group parallel study with a factorial design. Following 5 weeks familiarization subjects [BP range 109/66–168/105 mmHg] were randomly assigned to either a ‘low sodium, cholesterol lowering’ diet or a ‘low sodium, cholesterol maintaining’ diet. Half the subjects in each group were then assigned to 100 mmol/day NaCl supplement and the remainder to placebo. These diets were continued for 8 weeks. Seventy‐nine of the 91 hypertensives who completed the study were on antihypertensive therapy throughout.3. Mean urinary sodium excretion decreased from 137 (54 mmol/day (n= 43) at baseline (B) to 52 (32) mmol/day (n= 45,P= 0.0001) during intervention (I) in the low sodium groups and remained unchanged in the groups which received slow sodium (B = 129 [46],n= 43; I = 134 [29],n= 42). Diet record and plasma fatty acid analysis confirmed that the dietary aims of the study were achieved.4. Sodium restriction reduced supine and standing systolic BP by a mean (± s.e.m.) of 6±2 and 6±4 mmHg, respectively (P<0.005). The low fat/high fibre diet had no independent or additive effect on blood pressure reduction but reduced total and LDL cholesterol by an average of 0.74 and 0.59 mmol/L, respectively (P<0.0001).5. In terms of reducing overall risk of cardiovascular disease, diets which combine sodium restriction with measures to reduce LDL cholestero

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1990.tb01305.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

SUMMARY1. The diagnosis of isolated systolic hypertension, diastolic hypertension and normotension in elderly subjects, as defined by casual office blood pressure measurement, was compared with 24 h ambulatory blood pressure monitoring using an Accutracker II.2. Mean day‐time ambulatory blood pressure monitoring underestimated the casual systolic blood pressure in all three clinical groups. Diastolic pressure was not underestimated to the same extent.3. Ambulatory blood pressure monitoring best reflected casual blood pressure determination for normotensive subjects. In subjects with isolated systolic hypertension ambulatory blood pressures were only consistent with that diagnosis for 8% of the day time period. For 34% of the day time, their ambulatory blood pressures were consistent with diastolic/ mixed hypertension.4. It is concluded that isolated systolic hypertension may not be a sustained condition, but rather an isolated response to office measurement of blood pressur

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1990.tb01306.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

SUMMARY1. Left ventricular hypertrophy (LVH) was measured by echocardiography in 154 patients, mostly males, aged 55 years or more, with hypertension who had been well controlled for at least 2 years.2. Satisfactory studies with no other cardiac lesions were available for 103 patients; 52% had LVH and 48% had normal left ventricular dimensions.3. In patients with well controlled hypertension there was a high prevalence of LVH despite adequate control for at least 2 years. Neither the level of control nor the drugs used appeared to predict the outcome.4. Consideration needs to be given to earlier treatment, greater lowering of blood pressure, or different drugs to reduce this high prevalence of LVH.

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1990.tb01307.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

SUMMARY1. Male patients aged 50–75 years on treatment for hypertension in 1973 have been followed for 15 years.2. Overall mortality in the 271 patients was 63% and 41% died of vascular disease.3. Coronary artery disease or sudden death occurred in 44% of the patients who died and was between 2 and 6 times more common than in the general population.4. Treatment of hypertension has improved overall prognosis but mortality from coronary artery disease is more common than in the general populatio

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1990.tb01308.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY