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Biomedical subjects

K H Rahn

Publications and source records attributed to K H Rahn.

At least 181 records · Page 10Linked to original sources
PubMed1981

The sympathetic nervous system and the renin-angiotensin system in borderline hypertension.

1. Plasma catecholamine levels as well as plasma renin activity and plasma renin concentration were compared in normotensive volunteers and in subjects with borderline hypertension. All subjects were studied at rest and during bicycle ergometry. 2. The two groups of volunteer subjects did not differ in the plasma concentrations of noradrenaline and adrenaline, both at rest and during physical activity. The same was true for plasma renin activity and plasma renin concentration. Furthermore, urinary excretion of noradrenaline, adrenaline and 4-hydroxy-3-methoxymandelic acid was similar in both groups. 3. The results do not support the assumption that there is increased sympathetic activity in subjects with borderline hypertension.

Adolescent↗
PubMed1980

Influence of dobutamine and dopamine on hemodynamics and plasma concentrations of noradrenaline and renin in patients with low cardiac output following acute myocardial infarction.

The comparative hemodynamic effects of dobutamine and dopamine were studied in 6 patients with low cardiac output resulting from acute myocardial infarction. Plasma levels of noradrenaline and renin were measured before and during a 5 microgram/kg/min infusion of each of the drugs. Dobutamine had a more pronounced chronotropic effect, increased the systolic arterial pressure more and decreased the systemic vascular resistance less than dopamine at doses which had comparable effects on cardiac output. Dobutamine stimulated renin release, which might partly be the cause of the increased systolic arterial pressure. The drug reduced the plasma level of noradrenaline, which might be explained as a reflex reduction in sympathetic tone. Dopamine, however, did not stimulate renin release but it did enhance the plasma level of noradrenaline, which might be due mainly to the release of endogenous noradrenaline.

Adult↗
PubMed1978

Hypercalcitoninaemia in patients with pheochromocytoma.

As pheochromocytoma sometimes is accompanied by medullary thyroid carcinoma (in the sense of multiple endocrine adonomatosis type II = Sipple-Syndrome), serum calcitonin (CT) was measured by radioimmunoassay in 4 patients with pheochromocytoma. Before extirpation of the adreno-medullary tumor, serum CT was distinctly increased to 3 and 30 ng/ml in 2 of 4 patients, respectively. After removal of the tumor, serum CT was normal in the patients and pentagastrin stimulation produced no exaggerated CT response. In hydrochloric acid extracts from the two corresponding pheochromocytoma tissues, immunoreactive-Calcitonin (IR-CT) was detected, the concentrations amounting 1 and 4 ng/mg wet tissue. These findings suggest that hypercalcitonism in patients with pheochromocytoma cannot always be ascribed to the thyroid, i.e. increased calcitonin levels do not necessarily indicate a medullary carcinoma of this organ.

Adolescent↗
PubMed1978

Studies on the effects of propanolol on plasma catecholamine levels in patients with essential hypertension.

The influence of the beta receptor blocking agent propranolol on plasma catecholamine concentrations was studied in eight patients with essential hypertension. The study was of single blind crossover design. Propranolol given in oral doses ranging from 60 to 240 mg daily for a period of 3 weeks decreased blood pressure and heart rate. The beta-adrenergic blocking agent caused plasma catecholamine levels to increase both at rest and during bicycle exercise. Chromatographical analysis showed that concentrations of noradrenaline as well as of adrenaline rose during treatment with propranolol. However, dopamine-beta-hydroxylase activity in plasma was not altered. Furthermore, the urinary excretion of noradrenaline, adrenaline and 4-hydroxy-3-methoxy mandelic acid did not change during beta receptor blockade. The results are compatible with the assumption that antihypertensive doses of propranolol by decreasing cardiac output cause an activation of the sympatho-adrenal system.

Adult↗
PubMed1976

A comparison of catecholamine concentrations and dopamine-beta-hydroxylase activities in plasma from normotensive subjects and from patients with essential hypertension at rest and during exercise.

In 8 normotensive subjects and in 8 patients with essential hypertension total catecholamine content and dopamine-beta-hydroxylase (DBH) activity in plasma were measured at rest and during physical exercise. Catecholamine levels at rest were significantly higher in the hypertensive than in the normotensive persons whereas the 2 groups of subjects did not differ in DBH activity at rest. At a work load of 150 watts there was a more pronounced increase of the catecholamine concentrations and of the DBH activity in the hypertensive patients than in the normotensives. One may conclude from the data that there is an increased sympathetic nerve activity in patients with essential hypertension.

Adult↗
PubMed1976

[Number and kinds of drug side-effects in a medical clinic (author's transl)].

All drug side-effects - definite, probable and suspected - were noted during one year in 1592 patients. The severity of the side-effects was classified into mild (15%), moderate (6.5%), and severe (1%) forms. Fatal side-effects occurred without exception only in those patients who were severely ill so that any risk of treatment had been fully justified. Among patients with renal failure, malignant haematological diseases or Hodgkin's disease there was a particularly high incidence of side-effects. Although the proportion of the latter patients was only 15% of all in-patients, they accounted for 35% of patients with side-effects.

Adrenal Cortex Hormones↗
PubMed1976

Antihypertensive effects, plasma levels and beta-adrenergi blocking activity of racemic and dextrorotatory propranolol in man.

In hypertensive patients, whose blood pressure was decreased by racemic propranolol, the dextrorotatory isomer had no antihypertensive effect. The differences in antihypertensive activity of racemic and dextrorotatory propranolol cannot be explained by different plasma levels. The data indicate that the hypotensive effect of propranolol is due to beta-receptor blockade.

Blood Pressure↗