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At least 397 records · Page 22Linked to original sources
PubMed2001

Objective assessment of the sympatholytic action of the Nei-Kuan acupoint.

From animal experiments and clinical trials, we can think that acupuncture of Nei-Kuan (EH-6) is effective in the control of some vegetative functions. We have tried to determine the real reach of these assumptions by means of simple quantitative measurement methods, such as detection of cardiac frequency and systolic and diastolic blood pressure, and the sympathetic electrical response. The experiments were performed on 29 healthy volunteers. Basal values of these parameters were recorded, and also after orthodox Nei-Kuan acupuncture, non-acupunctural point puncture, supine lying by 15 min, Chü-Tze (EH-3) acupuncture and bipolar electrical stimulus of the median nerve at the Nei-Kuan level in the wrist. Such conditions were designed to evaluate non-specific puncture, repose and direct median nerve stimulation influences in the effects of Nei-Kuan acupuncture. We conclude that Nei-Kuan acupuncture strongly inhibits sympathetic tone, with reduction of cardiac frequency, systolic blood pressure and an important reduction of the amplitude of the sympathetic electrical response; the latency of the electrical response was also prolonged. Some weak effects on blood pressure and cardiac frequency were observed also, as non-specific effects of puncture and median nerve stimulation. From previous anatomical data, we hypothesize that the level of such actions is suprametameric, with strong implication of the diencephalon and cerebral cortex.

Acupuncture Points↗
PubMed2000

Endogenous circulating sympatholytic factor in orthostatic intolerance.

Sympathotonic orthostatic hypotension (SOH) is an idiopathic syndrome characterized by tachycardia, hypotension, elevated plasma norepinephrine, and symptoms of orthostatic intolerance provoked by assumption of an upright posture. We studied a woman with severe progressive SOH with blood pressure unresponsive to the pressor effects of alpha(1)-adrenergic receptor (AR) agonists. We tested the hypothesis that a circulating factor in this patient interferes with vascular adrenergic neurotransmission. Preincubation of porcine pulmonary artery vessel rings with patient plasma produced a dose-dependent inhibition of vasoconstriction to phenylephrine in vitro, abolished vasoconstriction to direct electrical stimulation, and had no effect on nonadrenergic vasoconstrictive stimuli (endothelin-1), PGF-2alpha (or KCl). Preincubation of vessels with control plasma was devoid of these effects. SOH plasma inhibited the binding of an alpha(1)-selective antagonist radioligand ([(125)I]HEAT) to membrane fractions derived from porcine pulmonary artery vessel rings, rat liver, and cell lines selectively overexpressing human ARs of the alpha(1B) subtype but not other AR subtypes (alpha(1A) and alpha(1D)). We conclude that a factor in SOH plasma can selectively and irreversibly inhibit adrenergic ligand binding to alpha(1B) ARs. We propose that this factor contributes to a novel pathogenesis for SOH in this patient. This patient's syndrome represents a new disease entity, and her plasma may provide a unique tool for probing the selective functions of alpha(1)-ARs.

Adrenergic alpha-1 Receptor Antagonists↗
PubMedDate not supplied

Evaluation of plasma catecholamines in humans. Correlation of resting levels with cardiac responses to beta-blocking and sympatholytic drugs.

The changes in systolic time intervals (STI) following reduction of adrenergic activity was used to validate supine resting plasma catecholamines (CATs) as an index of sympathetic activity. Blockade of sympathetic activity was achieved by two means in two groups: propranolol (10 mg i.v.) and clonidine (0.3 mg p.o.). The diminished sympathetic effect was evidenced by slowing (p less than 0.01) of heart rate with both drugs and the reduction (p less than 0.01) of blood pressure with clonidine. There was no correlation in our study between resting plasma CATs (norepinephrine alone or total), and changes in heart rate and preejection period (PEP). Moreover, to avoid changes in PEP that could be related to differences in blood pressure levels (clonidine-reduced blood pressure while propranolol did not), the changes in PEP were corrected for the change of mean arterial pressure (MAP) in the same patients (delta PEP/(delta MAP and % delta PEP/% delta MAP). No correlation could be found, still, between resting supine plasma CATs and these ratios. The difficulty in demonstrating a correlation between resting plasma CATs and the immediate cardiac response to adrenolytic agents can be explained by the number of factors influencing plasma levels. Circulating plasma CATs represent the spillover from adrenergic nerve endings, and, therefore, their level would depend on several factors including sympathetic nervous system activity, rate of reuptake, and rate of degradation.

Adrenergic beta-Antagonists↗
PubMed1989

Pathologic changes in the accessory sex glands of rats treated with a sympatholytic hypotensive agent (losulazine).

Groups of 25 male Sprague-Dawley rats were treated by gastric intubation with either vehicle control (modified methylcellulose) or a suspension of losulazine at 4, 8, 16, or 32 mg/kg/day for 1 yr. Ten rats/group were killed after 6 months of treatment. Reversibility of drug-induced changes was evaluated in 8 rats/group treated for 6 months and held without treatment for 5 months. Daily clinical signs and weekly body weight changes were monitored. Seminal vesicle/coagulating glands were weighed in rats treated for 6 months. Gross and microscopic evaluation of the accessory sex glands (ampullary glands, prostate, seminal vesicles and coagulating glands) was conducted in all rats killed at 6 months, after the recovery period, and in rats that survived through the one-yr treatment period. Ptosis, somnolence, and fecal softening were detected in all groups treated with losulazine. There was a nonreversible body weight gain retardation in groups treated with 8 to 32 mg/kg/day of losulazine for 6 months or 1 yr. Absolute and relative weights of the seminal vesicle/coagulating glands of treated rats were not significantly different from those of control rats. The ventral prostate in a few rats in all treated groups had yellow to tan granular foci. Treatment, but not dose-related sperm granulomas or glandular impaction with inspissated secretion (formation of corpora amylacia) in the ampullary glands, enhanced cellular exudation into the acini of the ventral prostate, and impaction of the seminal vesicles with altered granular to globular secretion were found in rats treated with losulazine.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1983

Combined diuretic and sympatholytic therapy in elderly patients with predominant systolic hypertension.

It has been speculated that the convenience and palatability of low-dose combination antihypertension treatment might enhance therapeutic effectiveness and compliance, especially in elderly patients. To test this possibility, patients over 60 years of age with predominant systolic hypertension were treated with a combination of a diuretic, chlorthalidone, and the centrally acting inhibitor of sympathetic activity, clonidine. The results of active treatment in these patients (n = 13) were compared with those of a placebo (n = 11). Active therapy with low doses of chlorthalidone and clonidine (usually once daily) controlled blood pressure (systolic pressure less than 140 mm Hg) in 12 of the 13 patients without inducing orthostatic hypotension. Administration of placebo did not result in significant changes in blood pressure. The diuretic-clonidine combination induced only small decreases in serum potassium levels and small increases in uric acid; no significant changes in creatinine clearance were observed. Both active and placebo therapy were tolerated without significant side effects. This study reveals that combined therapy with low doses of chlorthalidone and clonidine is effective, convenient, and palatable in controlling blood pressure in elderly patients with predominant systolic hypertension and supports the idea that treatment with sympathoinhibitory and volume-depleting agents is appropriate for this form of hypertension.

Aged↗
PubMed1979

Treatment plan for acute and chronic adrenergic poisoning crisis utilizing sympatholytic effects of the B1-B2 receptor site blocker propranolol (Inderal) in concert with diazepam and urine acidification.

In a large series of patients who have abused a variety of commercially available "amphetamine-like" agents as well as "street drugs" with CNS stimulant activity, the specific lytic effects of propranolol (Inderal) were utilized to reverse the dangerous hyperkinetic cardiovascular and frightening CNS phenomena noted in these non-comatose individuals. Presented here is a logical and clinically proven mode of therapy by which the authors have consistently, successfully, and safely managed such patients in "adrenergic crisis" by judicious titration of electrolytes, propranolol, and diazepam.

Acute Disease↗
PubMed1975

[Ambulatory treatment of arterial hypertension urinary the new combination "saluretic and beta-sympatholytic"].

91 hypertensive patients were treated for 8 weeks with a combination of Trasicor80Esidrix. For the first 2 weeks the fixed daily dose was 2 X 80 mg Trasicor and 25 mg Esidrix. From the third week of treatment onwards, the Esidrix dosage was maintained; the dosage of Trasicor 80 was either maintained, increased, or later decreased, according to the results obtained. Following 8 weeks treatment, the systolic blood pressure decreased from 190,4 (+/- 23,0) to 156,0 (+/- 17,7) mmHg, the distolic pressure decreased from 105,9 (+/- 13,5) to 87,6 (+/- 8,3) mmHg. The most marked decrease was recorded after the first week of treatment. In 84% of the cases, the results of the treatment were classed as good and very good; in 11% of cases the treatment was moderately successful, and in 4 patients (5%) the treatment had no effect. The tolerability of Trasicor80Esidrix was remarkably good (in 94% of cases, according to the physician's assessment). 10 patients complained of side effects, and 4 of them discontinued the treatment. Tasicor80Esidrix has been shown to be a safe, simple and practical form of treatment arterial hypertension. It was possible to maintain the selected initial dose of 2 X 80 mg Trasicor and 25 mg Esidrix in 2/3 of the patients.

Chemical Phenomena↗
PubMed1992

Relationship between the sympatholytic action of nebivolol and hypotension.

Nebivolol, a chemically novel beta 1-adrenoceptor antagonist, acutely lowers blood pressure in spontaneously hypertensive rats, anaesthetised normotensive dogs, and hypertensive patients. We have investigated the actions of dl-nebivolol in five conscious normotensive rabbits (sham, mean blood pressure (BP) of 82.2 +/- 4.1 mm Hg, mean +/- SEM) and four hypertensive rabbits (renal wrap hypertension) (wrap, mean BP of 117.6 +/- 1.5 mm Hg). Nebivolol (1 mg/kg i.v.) did not significantly lower the BP or heart rate in either group 30 min after injection. In the same rabbits, on another day, after autonomic blockade (mecamylamine), nebivolol (0.1, 0.3, and 1.0 mg/kg i.v.) right shifted the bolus i.v. isoproterenol tachycardia dose-response curves by dose ratios of 5, 18, and 90 in sham rabbits, respectively, and 5, 11, and 23 in wrap rabbits, respectively, indicating significant cardiac beta 1-adrenoceptor antagonism. In guinea pig isolated right atria pretreated with atropine (1 microM) and desipramine (DMI, 0.1 microM), norepinephrine concentration-response curves were antagonised competitively by nebivolol (3-100 nM), giving a pKb of 7.90. In separate atria without DMI pretreatment, neither nebivolol (100 nM) nor propranolol (100 nM) had any significant effect on the increase in the rate of norepinephrine efflux following electrical field stimulation (0.5-2 Hz, 3 min). These findings suggest that at concentrations of nebivolol that show substantial beta 1-adrenoceptor antagonism, there is no evidence of hypotension or bradycardia nor additional effects on cardiac norepinephrine release. Why nebivolol lowers blood pressure in some species but not in the conscious rabbit is not known.

Adrenergic beta-Antagonists↗