Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0085580 (essential hypertension)
 14,686 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In eight patients with essential hypertension the effect of 50 mg atenolol, once daily for 6 months, on vasodilation during epinephrine infusion and submaximal dynamic exercise was studied. The normal decrease of diastolic blood pressure during bicycle exercise, reflecting a decrease in total peripheral resistance not mediated by circulating epinephrine, disappeared during atenolol treatment. Low-dose infusion of epinephrine had no influence on systolic blood pressure both before and after atenolol. However, the decrease of diastolic blood pressure occurring before atenolol was abolished and the increase in heart rate was attenuated during atenolol treatment. Forearm vascular resistance decreased before and during atenolol to the same extent. So the normal physiologic vasodilation during submaximal dynamic exercise seems impaired during long-term treatment with atenolol. In addition the normal vasodilating response to an increase of circulating epinephrine to levels occurring during daily life stress seems impaired even with the low dose of this beta 1-selective beta-blocker.
 ...
PMID:Impaired vasodilation during long-term beta 1-selective beta-blockade in hypertensive patients. 339 63

The effect of 2 weeks treatment with propranolol or metoprolol on skin blood flow (SBF) at rest was examined in 12 diabetic patients with essential hypertension in whom gross large vessel disease had been excluded. Neither drug significantly altered resting skin blood flow. However we cannot exclude an important difference between the two beta-adrenoceptor blockers because of the great variability of SBF within subjects. A larger study and/or more accurate methods of measuring SBF are needed to determine if beta 1-selective adrenoceptor antagonists differ from non-selective beta-adrenoceptor blockers with respect to skin blood flow.
 ...
PMID:The effects of propranolol and metoprolol on skin blood flow in diabetic patients. 360 36

The efficacy and tolerability of the new ACE-inhibitor enalapril (MK 421) and the beta 1-selective adrenoceptor blocker atenolol for the treatment of primary hypertension were compared in a double blind parallel study. 12 patients were randomized to each drug. The doses of enalapril were 20 and 40 mg o.d. and of atenolol 50 and 100 mg o.d. for 4 weeks each, whereafter hydrochlorothiazide (HCTZ) 25 or 50 mg o.d. was added if necessary to achieve a supine diastolic blood pressure (BP) less than 90 mm Hg 24 hours after drug intake. Supine BP was reduced from 160 +/- 7/111 +/- 4 mm Hg to 153 +/- 13/101 +/- 9 mm Hg (p less than 0.05/p less than 0.005) with enalapril and from 163 +/- 17/109 +/- 6 mm Hg to 145 +/- 11/95 +/- 7 mm Hg (p less than 0.005/p less than 0.001) with atenolol. The addition of HCTZ caused a profound additive BP reduction to 132 +/- 7/88 +/- 6 mm Hg with enalapril and to 130 +/- 10/88 +/- 7 mm Hg with atenolol. There was no significant difference between the efficacy of enalapril and atenolol alone or combined with HTCZ. The reduction in mean arterial pressure with enalapril tended to correlate with pre-treatment stimulated plasma renin activity and 24 hours urinary kallikrein excretion. Both drugs tended to reduce serum and urinary aldosterone and kallikrein excretion to the same extent. There was one drop-out in each group, one due to impotence on the combination of enalapril and HCTZ and one due to peripheral coldness during atenolol treatment. Other side effects were mild. No toxic adverse effects were registered.
 ...
PMID:Enalapril and atenolol in primary hypertension--a comparative study of blood pressure lowering and hormonal effects. 608 25

The reference beta adrenoceptor antagonist propranolol reduces blood pressure in about 60% of patients with essential hypertension. Pressure is reduced in the supine, and erect positions without postural hypotension as well as during exercise. The average extent of pressure reduction is approximately 26/16 mm.Hg. Though all clinically available beta antagonists reduce blood pressure, the profile may be modified by both adrenotropic and non-adrenotropic ancillary properties. Of the adrenotropic properties, potency influences dose frequency and total body burden of drug. Selective beta 1 antagonism may enhance safety without reducing efficacy in patients with obstructive airways disease. Selective beta 2 blockade does not reduce blood pressure in experimental models or normal subjects, but the response in patients is unknown. Partial agonism may reduce efficacy if the degree of stimulant activity is too great. Of the non-adrenotropic properties, membrane stabilising properties are of relevance only in so far as such agents undergo extensive biotransformation resulting in either reduced efficacy when drugs are used at fixed doses or the formation of biologically active metabolites. The additional properties of either alpha adrenergic blockade or inhibition of vascular smooth muscle tone modify both the speed of onset and the haemodynamic profile. The interaction of these ancillary pharmacological properties is evaluated in this review.
 ...
PMID:The effect of different classes of beta-antagonists on clinical and experimental hypertension. 612 19

The purpose of this study was to evaluate the acute hemodynamic and hormonal effects induced by short-term exposure to loud noise in man. Loud noise (95 dBA or 100 dBA) caused an increase in blood-pressure in healthy normotensive subjects as well as in patients with essential hypertension. The blood pressure elevation was caused by vasoconstriction in patients with essential hypertension and in normotensive subjects with a positive family history of hypertension, while the blood pressure response in normotensive subjects without a family history of hypertension was due mainly to an increase in cardiac output. This might indicate that there are genetically determined differences in the cardiovascular response to noise. Stimulation with noise did not increase plasma levels of catecholamines, prolactin, cortisol or growth in normotensive subjects. In patients with essential hypertension plasma noradrenalin increased, while plasma adrenalin and plasma renin activity did not change. The increase in diastolic blood pressure caused by loud noise was not affected by beta 1-selective or non-selective beta-adrenoceptor blockade, nor was it changed by alpha 1-or combined alpha 1-and non-selective beta-adrenoceptor blockade. The elevation in blood pressure induced by noise is usually mediated by vasoconstriction, i.e. an alpha 1-effect. When alpha 1-adrenoceptors are blocked, the blood pressure response to noise is mediated by an increase in cardiac output, i.e. a beta-adrenoceptor mediated effect. It thus seems as if an increased pressure is essential during exposure to loud noise. If one part of the sympathetic nervous system is blocked, other parts can be activated in order to preserve the blood pressure on an elevated level. This indicates a temporary resetting of the baroreceptors during exposure to noise, which probably is mediated from the hypothalamus.
 ...
PMID:Cardiovascular effects of noise. 612 83

In early essential hypertension, an increase in cardiac output (CO) is seen in about two-thirds of the patients. In established essential hypertension, CO is usually normal or subnormal, while total peripheral resistance (TPR) is increased. Treatment with beta-adrenergic blocking agents accentuates these haemodynamic changes; in particular CO is further decreased. Comparison of the effects of beta-blockers with and without beta 1-selectivity and intrinsic activity reveals slight differences in the haemodynamic responses. Although none of the beta-blockers normalizes the haemodynamics, satisfactory blood-pressure reduction may be achieved at rest and during exercise with minimal side effects.
 ...
PMID:Haemodynamic effects of beta-receptor blockade during acute administration and chronic treatment. 613 Jun 78

The objective of this placebo controlled double-blind multicentre (six centres) trial was to investigate the safety and efficacy of ICI 141,292 (Visacor), a new selective beta 1-adrenoceptor antagonist with modest intrinsic sympathomimetic activity (ISA), in hypertensive patients. Fifty-nine patients with mild essential hypertension were randomized to two of five treatment alternatives (placebo, 50 mg, 100 mg 200 mg or 300 mg of ICI 141,292) each given once daily for 2 weeks with a 4 week placebo period before (run in) and in between (wash out) active periods. Thus, each of the five treatments was evaluated in 20-24 patients. After 2 weeks (24 h after last dose) the reduction in recumbent blood pressure for all doses except 50 mg of ICI 141,292 was statistically significant and in the order of 6/4 mm Hg. Standing systolic blood pressure was reduced in a dose-dependent way but only significant for 200 mg of ICI 141,292 (8 mm Hg). Heart rate changes (delta) less than 4 beats/min) were not statistically significant for any dose. It is concluded that ICI 141,292 was well tolerated and had a significant but weak antihypertensive effect which might be explained by too much beta 1-adrenoceptor ISA.
 ...
PMID:Initial clinical experience with ICI 141,292 (Visacor), a new selective beta 1-adrenoceptor blocker with ISA--a multicentre trial in 59 patients. 615 75

We performed this study in order to evaluate the antihypertensive effect of selective beta 2-adrenoceptor blockade. A highly beta 2-selective antagonist (ICI 118.551) was given to 15 male patients with essential hypertension who had previously shown a lowering of blood pressure in response to beta 1-selective or nonselective beta-adrenoceptor blockade. After a four-week placebo period ICI 118.551 was given (50 or 100 mg t.i.d.) for one week (randomized, double-blind). Before and 3 h after the first dose blood pressure, central and peripheral haemodynamics were studied by impedance cardiography and forearm plethysmography respectively. Blood pressure and heart rate were also measured after one week of treatment. After acute administration of drug cardiac output fell 14% (P less than 0.001) due to a fall in heart rate from 69 to 61 beats/min (P less than 0.002). Mean arterial pressure was unchanged (112 mmHg) and total peripheral resistance increased 18% (P less than 0.01). A similar rise in forearm resistance could be seen (14%). There was no reduction in blood pressure after one week of treatment although heart rate remained significantly reduced. Selective beta 2-adrenoceptor blockade does not lower blood pressure in patients previously responding to beta 1-or beta 1/beta 2-adrenoceptor blockade.
 ...
PMID:Antihypertensive mechanism of beta-adrenoceptor antagonism--the role of beta 2-blockade. 615 39

1. Noise stimulation (100 dBA) for 10 min caused a significant increase in diastolic (7.0%, P less than 0.001) and mean arterial blood pressure (4.3%, P less than 0.01) in patients with essential hypertension. 2. The blood pressure response to noise was due to an increase in total peripheral resistance (4.8%, P less than 0.02); heart rate, stroke volume and cardiac output were unchanged. 3. beta 1-selective adrenoceptor blockade (metoprolol) did not change the haemodynamic reaction pattern induced by noise. 4. Noise exposure during non-selective beta-adrenoceptor blockade (propranolol) caused an accentuated blood pressure response with increments of both systolic and diastolic blood pressure as well as a more pronounced rise in total peripheral resistance. 5. The haemodynamic changes induced by noise stimulation at 100 dBA totally disappeared after 5 min of quiet rest at 40 dBA.
 ...
PMID:Haemodynamic effects of noise exposure before and after beta 1-selective and non-selective beta-adrenoceptor blockade in patients with essential hypertension. 627 80

Treatment of fifteen patients with essential hypertension over four weeks using the beta 1-adrenoceptor blocking agent, metoprolol, resulted in a decrease in 24 h urinary excretion of kallikrein and aldosterone along with a decrease in plasma renin activity. There was no significant change in 24 h excretion rates of the free adrenal steroids deoxycorticosterone, 18-OH-deoxycorticosterone, corticosterone, cortisol or 18-OH-corticosterone during treatment, which were not significantly different from excretion rates of normal males, thus excluding inhibitory effects of adrenal steroids on urinary kallikrein activity. A positive correlation was found between plasma renin activity and urinary excretion of kallikrein during the control period and after 2 weeks on metoprolol, supporting the assumption of a preserved link between the renin-angiotensin-aldosterone system and the renal excretion of kallikrein in these patients. The decrease in kallikrein excretion during beta 1-adrenoceptor blockade in patients with essential hypertension may be explained by a reduction in sympathetic tone and by reduced activity of the renin-aldosterone system.
 ...
PMID:Effect of metoprolol on 24-hour urinary excretion of adrenal steroids and kallikrein in patients with essential hypertension. 636 71


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>