Elevated plasma catecholamines in young hypertensive and hyperkinetic patients: effect of pindolol.

Abstract

1 The sympathetic nervous system plays an important role in the regulation of blood pressure. Plasma catecholamine concentrations are considered to be reliable indices of sympatho-neuronal (noradrenaline) and sympatho-adrenal (adrenaline) activity and reactivity in man. 2 Sympathetic and adrenal activity and reactivity in young patients with essential hypertension or hyperkinetic heart syndrome were compared with an appropriate control group matched for age. The groups of hypertensive patients and patients with hyperkinetic heart syndrome could be clearly distinguished from control subjects on the basis of circulating catecholamine levels at rest. 3 A clear-cut increase in circulating noradrenaline and adrenaline was observed in young patients with essential hypertension and hyperkinetic heart syndrome at rest. Clinically, hypertensive patients were characterized by elevated systolic and diastolic blood pressure and increased heart rate, whereas patients with hyperkinetic heart syndrome had increased heart rate and increased systolic blood pressure, whereas diastolic blood pressure was normal. At rest, there was a significant positive correlation between heart rate and circulating catecholamines in both groups of patients. In hypertensives a positive correlation between heart rate and plasma adrenaline concentrations, in patients with hyperkinetic heart syndrome a positive correlation between heart rate and plasma noradrenaline concentrations could be observed. In addition a positive correlation between plasma noradrenaline concentrations and systolic blood pressure in all groups of patients studied, was obtained. 4 Sympatho-neuronal and sympatho-adrenal reactivity during mental stress or physical exercise increased in both groups of patients, mirrored by an increase in blood pressure and heart rate.5 Pindolol, a potent non-selective P-adrenoceptor blocking drug with intrinsic sympathomimetic activity and minimal membrane stabilizing properties, administered in a single oral dose of 10 mg, diminished the exaggerated sympathetic tone in both groups of patients by attenuating circulating catecholamine levels at rest or during mental stress, but not during physical exercise.

Beta‐adrenoceptor blockade and psychic stress in man. A comparison of the acute effects of labetalol, metoprolol, pindolol and propranolol on plasma levels of adrenaline and noradrenaline.

“…It is generally agreed that long-term treatment with ,Badrenoceptor blockers such as propranolol and labetalol causes an increase in the plasma concentration of adrenaline and noradrenaline (Christensen et al, , 1979Carlsen et al, 1980). Therefore it is of interest that Brecht et al (1976), Bonelli et al (1979) and Dominiak & Grobecker (1982) found that the plasma concentrations of catecholamines were reduced after treatment with pindolol, a nonselective 13-adrenoceptor blocker with ISA (Table 1).…”

Sympathoadrenal dysfunction in rats with chronic neurogenic hypertension

“…High circulating adrenaline levels can contribute to the maintenance of high blood pressure in rats (Rand et al, 1983). An increased level of circulating adrenaline has also been observed in young patients with essential hypertension (Dominiak and Grobecker, 1982).…”

“…Both the peripheral (Alexander et al, 1976) and central (Chalmers, 1975) sympathetic systems have been proposed to be involved in the development of this model (Alexander et al, 1976). There is increasing evidence that, in addition to sympathetic nerves, the adrenal medulla has a role in neurogenic as well as in other animal models of hypertension and in selected cases of human essential hypertension Dominiak and Grobecker, 1982). We undertook the study of plasma, adrenal and heart catecholamine levels in conscious, unrestrained rats with chronic neurogenic hypertension and their sham-operated controis.…”

Circulating and tissue catecholamines in rats with chronic neurogenic hypertension

“…Central and peripheral sympathetic nerves have been recently demonstrated to play a role in these models (16,17,29,30). The participation of sympathetic neurons in selected cases of human essential hypertension has been postulated as well (11). For this reason, an in-depth study of sympathetic activity in adequate animal models could be useful to advance our knowledge of the sympathetic factor(s) possibly involved in the human disease.…”