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Biomedical subjects

F R Bühler

Publications and source records attributed to F R Bühler.

At least 19 recordsLinked to original sources
PubMed1979

Plasma noradrenaline correlates with alpha-adrenoreceptor-mediated vasoconstriction and blood pressure in patients with essential hypertension.

1. The relationships between plasma noradrenaline concentration at rest and blood pressure, as well as increase in forearm blood flow in response to a brachial artery infusion of the alpha-adrenoreceptor-blocking agent phentolamine, were investigated in hypertensive and normotensive subjects of similar age. 2. In 44 hypertensive patients plasma noradrenaline correlated with systolic, diastolic and mean blood pressures, but no difference in the mean plasma noradrenaline concentration was found. 3. In 11 patients and 14 normotensive subjects alpha-adrenoreceptor blockade resulted in a similar increase in forearm blood flow. Only in the patients, however, was this increase related to plasma noradrenaline and blood pressure. 4. In patients with established essential hypertension plasma noradrenaline can be considered to be a marker of alpha-adrenoreceptor-mediated vasoconstriction, which, in part, determines the height of the blood pressure.

Adolescent↗
PubMed1978

[Detection of unrecognized hypertensives. A duty for longterm attendance (author's transl)].

The magnitude of the problem of hypertension is reflected in figures from the United States and Europe: with an incidence of about 15% of hypertensives in the adult population, about 1/3 of these individuals are unrecognized, a further third are indeed recognized but only inadequately treated or not at all, and only 1/3 are being satisfactorily treated. For this reason, not only the detection of unrecognized hypertensives must be dealt with, but also the problem of longterm supervision must be gone into at the same time. Were the adult population of the Federal Republic of Germany to be included in a "filter" investigation, about 3 million confirmed untreated hypertensives would have to be examined further and possibly treated. Also in an investigation of much smaller extent, the question of efficiency and tolerance must be raised.

Adolescent↗
PubMed1976

[Exercise hemodynamics and renin before and after acute beta block in patients with essential hypertension].

Hemodynamic and renin studies at rest and during graded upright ergometry were performed in 21 patients with essential hypertension before and after propranolol. Beta-adrenergic receptor blockade reduced exercise-stimulated cardiac and renin responses significantly more when compared with the corresponding effects at rest. Propranolol increased peripheral resistance at rest but not during exercise. The degree of the individual hemodynamic changes after propranolol correlated better with the corresponding control values than with age or renin. A direct relationship between the percent reduction of heart rate and renin responses after acute beta-blockade indicates a parallel suppression of cardiac and renal receptor functions.

Adrenergic beta-Antagonists↗
PubMed1976

[Dynamics of plasma catecholamines and beta-adrenoreceptor functions. Use of a new radio-enzymatic micro-method].

The new method for simultaneous determination of noradrenaline (NA), adrenaline (A) and dopamine in 50 mul plasma has proved specific, sensitive and readily reproducible. In 6 healthy volunteers NA was 190 pg/ml and A 63 pg/ml in the supine position and rose during graded upright exercise to NA 819 pg/ml and A 161 pg/ml (150 watts; p less than 0.001 and less than 0.05 respectively). NA and A paralleled exercise tachycardia (r = 0.894; p less than 0.001) and renin stimulation (r = 0.620; p less than 0.001). 21 patients with essential hypertension exhibited relatively higher NA concentrations both at rest and during graded exercise (p less than 0.05 for both). Exercise-stimulated NA and A further rose following 0.15 mg/kg propranolol i.v. (p less than 0.01 and p less than 0.05 respectively). With increasing age and blood pressure, plasma catecholamine concentrations rise while the reactivity of heart rate and renin secretion decreases. Acute pharmacological blockade of beta-adrenoreceptors increases catecholamine overflow in similar fashion to the physiological dissociation of plasma catecholamines and adrenoceptor responsiveness.

Adult↗
PubMed1976

A beta-blocker-based antihypertensive drug program guided by age and renin.

From analyses of the effectiveness of beta-blocker monotherapy in relation to the patient's age and to pre-treatment renin determinations an antihypertensive drug program is proposed in which beta-blockers form the cornerstone. Patients with essential hypertension can be subdivided into groups with low (19%), normal (59%), or high (23%) renin sodium index. The proportion with low renin hypertension increases with age. Patients with high renin fall into two categories: younger patients with fairly mild hypertension and older pateients with more severe hypertension and signs of renal disease. The antihypertensive efficacy of beta-blocker monotherapy is best in high renin forms, good but less consistent in normal renin patients and uniformly bad in low renin hypertensives. In relation to age, beta-blockers normalized blood pressure (larger than or equal to 95 mmHg diastolic) in three-quarters of the younger than 40-year-olds, in about half of those aged 40--60 years, but in only 20% of those aged over 60 years. On this basis, it is postulated that the older patients with a low renin exhibit a relatively hypoadrenergic state while those with a normal or high renin--for a given age and elevated pressure--have a relatively increased adrenergic nervous activity. Because the beta-blockers have a potent suppressive action on the renin-angiotensin system--and, as a consequence, on angiotensin vasoconstriction, aldosterone volume expansion and central stimulatory feedback mechanisms--their antihypertensive mode of action may be linked to an important extent, though not exclusively, to renin suppression.

Adrenergic beta-Antagonists↗
PubMed1976

Renin and age as determinants of a predominantly betablocker-based antihypertensive drug program.

Patients with essential hypertension can be subdivided into groups with low (19%), normal (59%) or high (23%) renin sodium index. The proportion with low renin hypertension increases with age. Patients with high renin fall in two categories: younger patients with fairly mild hypertension and older patients with more severe hypertension and signs of renal disease. The antihypertensive efficacy of betablocker monotherapy is best in high renin forms, good but less consistent in normal renin patients and uniformly bad in low renin hypertensives. In relation to age, betablockers normalized blood pressure (less than or equal to 95 mm Hg diastolic) in three-quarters of the younger-than-40-year-olds, in about half of those 40-60 years of age but in only 20% of those over 60 years. On this basis, it is postulated that the older patients with a low renin exhibit a relatively hypoadrenergic state whereas those with a normal or high renin--for a given age and elevated pressure--have a relatively increased adrenergic nervous activity. Because the betablockers have a potent suppressive action on the renin-angiotensin system--and, as a consequence, on angiotensin vasoconstriction, aldosterone volume expansion and central stimulatory feedback mechanisms--their antihypertensive mode of action may be linked to an important extent, although not exclusively, to renin suppression.

Adrenergic beta-Antagonists↗