Some aspects of pharmacological profile of sodium curcuminate

Rapid i.v. injection of sodium curcuminate (NaC) produced transient hypotension and bradycardia in anaesthetized dogs and cats which were not blocked by bilateral vagotomy, atropine, mepyramine or propranolol. In open-chest anaesthetized cats, decrease in blood pressure and heart rate was accompanied by simultaneous transient reductions in left ventricular systolic pressure, maximal rate of rise of left ventricular pressure and a concomitant increase in left ventricular end-diastolic pressure. It was concluded that the transient hypotensive effect of NaC is due to its myocardial depressant action. NaC exhibited negative inotropic and chronotropic effect on isolated perfused rabbit heart, an antispasmodic effect on smooth muscle of dog s intestine in vivo and of vas deferens of guinea-pig in vitro but no effect on the rectus abdominis muscle of frog or its response to cholinergic stimulation.

Nature of the beta-adrenoreceptors in the tracheal smooth muscle of the adult pig

Relaxant responses to isoprenaline (ISO), adrenaline (ADR) and noradrenaline (NA) were investigated on carbachol-contracted, isolated tracheal smooth muscle preparations of the adult pig to determine the nature of the beta-adrenoreceptors present. The order of relaxant potencies of the catecholamines on this preparation was ISO greater than ADR greater than NA. The potency ratio at 37 degrees C was 1:0.06:0.005. This suggests that beta 2-adrenoreceptors predominate in isolated tracheal smooth muscle of the adult pig. Though the order of potency for the above catecholamines did not change, at the lower temperatures of 29 degrees and 33 degrees C, the potency ratios were slightly modified to 1:0.0.98:0.004 and 1:0.07:0.004 respectively. pA2 values on pig tracheal smooth muscle were 8.65 and 9.13 respectively, for the non-selective beta-blockers propranolol and alprenolol, and 5.63, 5.20 and 6.26 respectively, for the beta 1 selective blockers practolol, atenolol and metoprolol and 6.82 for the beta 2 selective beta-blocker, H 35/25. The results suggest the existence and predominance of beta 2-adrenoreceptors in tracheal smooth muscle of the adult pig.

Anti-spasmogenic effect of cyproheptadine on guinea-pig ileum

Antagonistic activity of cyproheptadine against common spasmogens, like acetylcholine, histamine, serotonin, bradykinin and angiotensin, was studied on isolated guinea-pig ileum. Cyproheptadine produced a reversible antagonism of non-competitive type and was most effective against serotonin. It was less potent against histamine, bradykinin and angiotensin and least potent against acetylcholine.

Effect of beta-adrenergic blockers on isolated coronary arterial strip and tracheal smooth muscle of pig

Isolated coronary arterial strip and tracheal smooth muscle of pig, containing predominantly beta 1- and beta 2-adrenoceptors respectively, have been used for estimating the comparative potency of nine beta-adrenergic blocking agents. The order of potency of the antagonists on the isolated coronary arterial strip was propranolol greater than alprenolol greater than H 64/52 greater than H 64/55 greater than practolol greater than H 87/07 greater than atenolol greater than metoprolol greater than H 35/25, whilst the order of potency on the pig tracheal smooth muscle was alprenolol greater than propranolol greater than H 35/25 greater than H 87/07 greater than H 64/55 greater than H 64/52 greater than metoprolol greater than practolol greater than atenolol. Propranolol and alprenolol were almost equipotent in both the preparations and hence were nonspecific. Although practolol, metoprolol, H 64/55 and H 87/07 were beta 1-selective, their selectivity ratio was comparatively smaller than that of atenolol and H 64/52. The study indicates that H 64/52 and atenolol are the most specific beta-adrenergic blocking agents on isolated coronary arterial strip of pig and that their beta 1/beta 2-ratios are 126 and 120 respectively. H 64/52 like atenolol may be of therapeutic value in cardiovascular disorders.

Feline endotoxin shock: effects of methylprednisolone on kininogen-depletion, on the pulmonary circulation and on survival

1 Escherichia coli endotoxin, administered intravenously in a dose of 2 mg/kg to pentobarbitone anaesthetized, artificially ventilated cats resulted in pulmonary hypertension, systemic hypotension and an immediate (1-2 min) 30-40% reduction in plasma kininogen, an effect which probably indicates a release of plasma kinins. 2 Methylprednisolone (30 mg/kg), when administered 30 min before endotoxin, did not influence the endotoxin-induced pulmonary hypertension or systemic hypotension but completely prevented the depletion of plasma kininogen. 3 In spontaneously breathing cats, methylprednisolone, administered 30 min after endotoxin, caused a rapid repletion of kininogen and prolonged survival (47% at 6 h compared to 10% in the endotoxinalone animals). Methylprednisolone did not appear to influence lactate production or the hyperventilation observed during the delayed endotoxin shock phase. 4 It is concluded t,at methylprednisolone does not prevent the release, by endotoxin, of a pulmonary vasoconstrictor prostaglandin, or its effects, but that perhaps by preventing kinin release it may reduce endotoxin-induced capillary leakage.

Some effects of dihydroergocrisine and of phentolamine mesylate on renal function in rats

Single injections of dihydroergocristine (dhe) (25, 50 and 100 μg, i.p.) did not depress the systemic arterial pressure but antagonized the pressor effects of (-)-noradrenaline (100 μg, s.c.) in unanaesthetized rats. The effects of these doses of dhe on water diuresis were minimal: slight K retention, a rise in urinary Na:K and a slight but significant fall in the clearance of p-aminohippuric acid were noted. Single injections of phentolamine mesylate (10, 20 and 40 μg, i.p.) greatly depressed systemic arterial pressure and reduced the glomerular filtration rate and p-aminohippuric acid clearance and the excretion of water and Na proportionately, but markedly. The Na:K in the urine rose. Chemical denervation of the kidneys either with dhe, 32 μg, or phentolamine, 2 mg, thrice daily for 5–7 days decreased, but for 14 days increased, the juxtaglomerular index of the kidneys. Parallel changes were found in the extractable renin. Continued treatment with dhe (32 μg thrice daily for 2 weeks) raised, and hyperduric adrenaline (250 μg twice daily for 1 week) lowered the stores of growth hormone in the adenohypophysis. Continued treatment with dhe, 32 μg thrice daily produced antidiuresis and retention by the third day lasting to the fifth. This condition had reversed by the eighth day.