propanolol atenolol

1-(3-Chlorophenyl)piperazine (mCPP) (0.125-1.0 mg/kg i.p.), previously shown to inhibit social interaction, dose-dependently reduced exploration of the open arms of an elevated plus-maze. These findings suggest anxiogenic properties. The effect of mCPP was more potently inhibited by 1-(1-naphthyl)piperazine than by ketanserin, indicative of its mediation via activation of 5-HT2C rather than 5-HT2A receptors. The 5-HT1B receptor agonist CGS 12066B did not antagonise the anxiety-like response to mCPP, and further reduced exploration at the highest dose tested (10 mg/kg i...

The result of an exercise ECG can be represented on an XY chart by four monovariate (normal) distributions: heart rate (divided by X axis); blood pressure (divided by Y axis); Working time deficit (-X axis); ST depression (-Y axis); and two bivariate (elliptic) distributions: double product (divided by X divided by Y quadrant); ST X time-deficit index (-X -Y quadrant). Charts for 100 normal men, 100 normal women, 100 coronary men, and 100 coronary women were first of all built up. Charts of 100 patients under propanolol, 33 under atenolol, 47 under nidefipine, 13 under verapamil, and 44 under isosorbide dinitrate were then compared with those from coronary men...

Fifty-nine hypertensive women were treated with beta-blockers during 60 pregnancies. Acebutolol was used in 28 cases, pindolol in 21, atenolol in 10 and propanolol in one. Concomitant administration of dihydralazine was required in 6 cases. In 6 women beta-blockade was started before, and continued throughout pregnancy. Treatment was initiated after the 13th week of gestation in the majority of patients and before the 12th week in two. Twenty women were known to have hypertension long before they became pregnant, and renal disorders were diagnosed in seven...

Chronic beta-blockade with the cardioselective blockers practolol and atenolol had no attenuating effect on blood-pressure increases provoked by cold pressor test or by plasma expansion. Reports in the literature of an exaggerated cold pressor test reaction under propanolol therapy could be confirmed with practolol and atenolol. This may be regarded as an advantage of cardioselective blockade. The increase of the cardiac output after plasma expansion is enhanced during cardioselective beta-blockade. This could result from a reduced action of cardioselective blockers on the capacitance vessels...

To determine whether beta-adrenoceptor blockade lowers blood pressure by potentiating arterial baroreflex sensitivity (BRS), we compared the effect of acute i.v. and chronic oral beta-blockade on the BRS (phenylephrine technique) of 51 subjects with essential hypertension. Subjects were randomly assigned in a double-blind protocol to one of atenolol, metoprolol, pindolol or propranolol. There was an increase in BRS, unrelated to changes in heart rate, after both acute and chronic beta-blockade. This effect was most evident in younger and less hypertensive subjects...

In the search for improved drugs much attention has been focussed on the need for greater selectivity of action. Knowing that all drugs are poisons, the pharmacologist must attempt to define the required effect more narrowly but remain aware of potential unwanted effects. These may come as a result of the primary pharmacological effect or be due to other properties of the drug molecule manifesting themselves in clinical use. This paper illustrates the process of drug discovery and development with special reference to beta-adrenoceptor antagonists...

A consistent body of evidence indicates that in the preterm and full-term newborn drug disposition is reduced when compared to that of infants, grown-up children, and adults. Newborns are rarely treated directly with antihypertensive agents; however they can be exposed to the action of various antihypertensive drugs in utero and during their first week of extrauterine life in the case of hypertensive mothers treated through pregnancy. In such cases, the persistence of the antihypertensive agent during the first days of life may have important consequences on neonatal haemodynamics and on the function and the maturation of vital organs such as lungs and kidneys...

The beta 2-adrenoceptor agonist, clenbuterol (initially 5 mg/kg), was found to significantly reduce plasma tyrosine and raise brain tryptophan levels (P less than 0.01). By comparison, decreases in plasma tryptophan and increases in brain tyrosine were small and often nonsignificant. Amino acid levels measured in different brain regions revealed that the elevations were similar among the cerebellum, striatum, and cortex. These effects were partially blocked by propanolol but not by atenolol. The ED50 was estimated from dose-response curves to be about 0...

The effect of the beta-adrenergic receptor agonist isoproterenol on guanine nucleotide-dependent phospholipase C (PLC) activity was examined in turkey erythrocyte membranes prepared from [3H]inositol-labeled turkey erythrocytes. In the presence of guanosine 5'-(gamma-thiotriphosphate) (GTP[S]) isoproterenol caused a dose-dependent stimulation of [3H]inositol phosphate ([3H]InsP) formation. The activation of PLC by GTP[S] occurred after an initial lag period of 1-2 min and was followed by a sustained rate of [3H]InsP formation which remained linear for 4-5 min...

Sixty healthy male volunteers were randomly assigned to one of six treatment groups on a double-blind basis: 1. Atenolol = 50 mg t.d.s. 2. Methyl dopa = 250 mg t.d.s. 3. Propanolol = 40 mg t.d.s. 4. Reserpine = 0.2 mg t.d.s. 5. Placebo. 6. Control = no tablets. Tests were carried out before treatment, 2 h after the first dose, after seven doses, and after 21 doses. Subjects performance on the Stroop Colour-Word Test was assessed in terms of (a) word reading speed and (b) an 'interference' score based on the difference between the incongruous colour word and colour card reading speed...

On oral administration, the non-selective beta-adrenoceptor blocking drugs (+/-)-bufuralol, (-)-bufuralol, propanolol, oxprenolol, pindolol and alprenolol produced hypotensive responses in the conscious cat; (+)-bufuralol was without effect. The selective beta-adrenoceptor blocking drugs practolol and atenolol had no effect on blood pressure but tolamolol elicited a hypotensive response. All the drugs tested reduced the tachycardia due to intravenous isoprenaline in the conscious cat; however, not all doses of these drugs reduced blood pressure...