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Biomedical subjects

M Tree

Publications and source records attributed to M Tree.

30 records · Page 2Linked to original sources
PubMed1976

Renal abnormalities and vascular complications in primary hyperaldosteronism. Evidence on tertiary hyperaldosteronism.

The frequency of underlying renal or renal artery disease, and the incidence of vascular complications were reviewed in a series of 136 cases of primary hyperaldosteronism. This was in order to investigate the possible existence of 'tertiary' hyperaldosteronism, and to examine the commonly held view that primary hyperaldosteronism is a relatively benign form of hypertension. Ten cases (7-4 per cent) had evidence of renal artery stenosis and eleven (8-1 per cent) parenchymatous renal disease. In comparison with the reported frequency in large general series of hypertensives, these data show no evidence of an excess of underlying renal disease. It is unlikely, therefore, that autonomous aldosterone secreting adenomata occur commonly as a consequence of prolonged secondary hyperaldosteronism. Four cases (2-9 per cent) had evidence of the malignant-phase of hypertension, and over a mean observation time of 5-9 years, 31 cases (22-8 per cent) developed 39 vascular complications. It appears, therefore, that vascular complications are not rare in primary hyperaldosteronism, and early and effective treatment is thus necessary.

Adenoma↗
PubMed1975

Is low-renin hypertension a stage in the development of essential hypertension or a diagnostic entity?

A study of the frequency distribution of plasma-renin concentration in 81 patients with essential hypertension produced no evidence of a distinct sub-population with low renin levels. An arbitrary dividing line was used, therefore, to define low-renin hypertension (36% of patinets). Patients in this group were older than those with normal renin levels, and there was a significant negative correlation between renin and age among all patients. Low-renin hypertension was not characterized by increased exchangeable sodium, but exchaneable postassium was significantly lower than in patients with normal plasma-renin. This difference became insignificant when five patients in the low-renin group with persistent hypokalaemia were excluded. It is concluded that low-renin hypertension does not represent a separate diagnostic entity but that plasma-renin falls with age in essential hypertension.

Adult↗
PubMed1975

Effect of intravenous frusemide on plasma renin concentration: suppression of response in hypertension.

1. Intravenous frusemide produced in normal subjects a prompt rise of plasma renin concentration which correlated with urinary sodium. 2. The renin response to frusemide was suppressed in patients with primary hyperaldosteronism. 3. In patients with low-renin hypertension and normal renin essential hypertension, the renin response to frusemide was similarly suppressed. 4. Suppression of the renin response to frusemide is therefore a feature of hypertension not confined to patients with primary hyperaldosteronism and low-renin hypertension. 5. Thus low-renin hypertension does not appear to constitute a distinct diagnostic entity. 6. It is suggested that suppression of the renin response is part of a long-term renal adaptation to high blood pressure.

Adult↗
PubMed1975

Rectal potential difference in the diagnosis of aldosterone excess.

Rectal potential difference (pd) is directly related to the plasma aldosterone concentration, and rises when aldosterone is stimulated by sodium deprivation. However, when the measurement of rectal pd was tested at a screening test for hyperaldosteronism in 19 hypertensive subjects, four of the eight with primary hyperaldosteronism had a normal pd and four of the eight without aldosterone excess had an abnormally raised potential difference. The technique cannot therefore be recommended as a routine screening test for hyperaldosteronism. No relationship was found between rectal pd and hypertension associated with excess of deoxycorticosterone. Rectal pd rises in response to the mineralocorticoid-like agent carbenoxolone.

Adult↗
PubMed1975

Plasma angiotensin II, renin, renin-substrate and aldosterone concentrations in acute renal failure in man.

Plasma concentrations of angiotensin II, renin, renin-substrate and aldosterone were measured in cases of acute renal failure. Angiotensin II, and renin levels were abnormally high on at least one occasion in nearly all patients. Mean angiotensin II and renin levels were highest in the first ten days of the disease. There was a highly significant positive correlation between concurrent estimations of renin and angiotensin II. Renin-substrate was also frequently elevated, but the correlations with renin and angiotensin II were not statistically significant. Despite the frequently marked elevation of plasma angiotensin II, only 2 of 17 measurements of plasma aldosterone were abnormally high. There was no significant relationship between aldosterone and plasma concentrations of angiotensin II, renin, sodium or potassium. The data are discussed in relation to current hypotheses implicating renin and angiotensin in the pathogenesis of acute circulatory renal failure.

Acute Kidney Injury↗
PubMedDate not supplied

Occupational lead exposure and renin release.

Hypertension may result from chronic lead exposure. Lead poisoning arising from "moonshine whiskey" drinking has been associated with a rise in plasma renin activity. In the present study, plasma renin concentration following intravenous administration of frusemide was measured in eleven subjects with moderate or severe lead poisoning of industrial origin. The results were compared with those obtained for seven normal, control subjects. There was no significant difference in response obtained in the two groups. Industrial lead poisoning does not appear to affect renin release. The combined insult of lead and alcohol may explain the findings in the previous study.

Adolescent↗