Biomedical subjects

A E Doyle

Publications and source records attributed to A E Doyle.

At least 109 records · Page 6Linked to original sources

PubMed1976

The role of noradrenaline and other transmitter hormones in the pathogenesis of hypertension.

1. Studies with a sensitive radioenzymatic assay for plasma noradrenaline suggest there is a selective overactivity of the sympathetic nerous system in essential hypertension. 2. Serotonin turnover in the mesenteric vessels is approximately twice that of noradrenaline and it is suggested that serotonin may interact with noradrenaline to maintain vascular resistance. 3. Methodology which allows the study of local sympathetic turnover in nuclei of the central nerous system and in peripheral blood vessels is decribed. This approach has been used to study non-innervated sympathetic turnover observed in phaceochromocytoma.

Adrenal Gland Neoplasms↗

PubMed1976

Interaction of angiotensin II with catecholamines in the circulation of the dog and cat.

1. The blood-bathed organ technique was employed to study the effects of angiotensin II and catecholamines on an isolated everted rat aorta bathed in the extracorporeal circulating blood of adult dogs and cats. 2. When the injections were made into the bathing blood close to the everted rat aorta, angiotensin II was half as potent as adrenaline or noradrenaline on a molar basis. 3. After intravenous injections, the vasoconstrictor potency of angiotensin was twenty times that of adrenaline or noradrenaline on the everted rat aorta. The increase in potency was due to the interaction of angiotensin II with catecholamines on the preparation. 4. Intravenous phenoxybenzamine abolished the potentiated vasoconstrictor effect of angiotensin II on the blood-bathed everted rat aorta, but it did not abolish the pressor effect of angiotensin II on the cardiovascular system of the animals. The results suggest that catecholamines released into the circulating blood by intravenous angiotensin II do not play an important role in the pressor effect of angiotensin II.

Angiotensin II↗

PubMed1976

Morbidity and mortality in hypertension.

There is substantial evidence of increased mortality and morbidity in hypertension. There is also clear evidence that antihypertensive treatment reduces the incidence of stroke and reduces the incidence of heart failure, but leaves myocardial infarction as a major cause of death and disability.

Cerebrovascular Disorders↗

PubMed1975

Plasma renin, urinary sodium excretion and vascular disease.

1. Urinary sodium excretion and plasma renin activity have been measured in a group of persons with untreated mild hypertension and in a control normotensive group. 2. Preliminary analyses of the data indicate that the daily sodium excretion was significantly higher in the hypertensive group but the plasma renin activity did not correlate significantly with the urinary excretion of sodium. 3. These findings suggest that sodium intake was significantly greater in a population with mild hypertension than in a comparable normotensive group.

Cerebrovascular Disorders↗

PubMed1975

Plasma noradrenaline concentration and blood pressure in essential hypertension, phaeochromocytoma and depression.

1. Mean plasma noradrenaline concentration was elevated in forty-four patients with established essential hypertension. Eighteen of the hypertensive patients had resting plasma noradrenaline concentrations in the normal range. 2. Patients with endogenous depression had higher mean plasma noradrenaline concentrations but significantly lower blood pressure than patients with essential hypertension. 3. Patients with phaeochromocytoma had plasma noradrenaline concentrations twenty-eight times greater than those found in essential hypertension, but blood pressures were less than 20% higher. 4. It is concluded that excess of sympathetic drive only partly explains the level of the blood pressure in essential hypertension.

Adrenal Gland Neoplasms↗

PubMed1975

Beta-adrenergic receptor blocking drugs, hypertension and plasma renin.

1 Propranolol and pindolol reduced both the blood pressure and plasma renin activity when given chronically to hypertensive patients. 2 There was no correlation between the fall in blood pressure and the fall in plasma renin activity. 3 Neither the basal nor the random plasma renin activity predicted the patients who would respond to beta-adrenergic receptor blocking drugs. 4 Oral propranolol reduced plasma renin activity but did not reduce blood pressure within 4 h of administration; oral pindolol reduced blood pressure but did not reduce plasma renin activity within 4 h of administration. 5 The reduction of blood pressure by propranolol and pindolol does not seem to be mediated by changes in plasma renin in most patients.

Adult↗

PubMed1975