Effect of one derivative of 2-aminotetralin on the alpha-adrenergic receptors of isolated vessels.

Experiments were made to test the effects of originally synthesized piperazine derivative of 2-aminotetralin (P11) on the alpha-adrenergic receptors of isolated vessels. Inhibition of the contracting effects of exogenously introduced noradrenaline into isolated rabbit ear artery was found at concentrations of P11 and phentolamine 1 X 10(-8) to 1 X 10(-4) M. IC50 for P11 is 0.68 microM, for phentolamine -- 0,40 microM. There is a certain shift to the right of the concentration effect curves for noradrenaline in isolated strip of rabbit aorta when P11 and phentolamine are applied in concentrations of 1 X 10(-7) to 1 X 10(-5) M. pA2 for P11 is 7.31, for phentolamine -- 8.04. Potentiation of the maximum effect of noradrenaline is observed after P11 1 X 10(-5) M, which decreases upon preliminary administration of cocaine 1 X 10(-5) M and propranolol 1 X 10(-6) M. The tested compound manifests alpha-adrenergic blocking action in the organs studied.