Printed in USA. INFLUENCE OF COCAINE AND DESIPRAMINE ON THE CON- TRACTILE RESPONSE OF ISOLATED RABBIT PULMONARY ARTERIES AND AORTAE TO TRANSMURAL STIMULATION

TODA, Noaoau: Influence of cocaine and desipramine on the contractile response of iso-lated rabbit pulmonary arteries and aortae to transmural stimulation. 3. Pharmacol. Exp. Ther. 179: 198-206, 1971. Contractile responses of spirally cut strips of the main pulmonary artery and the thoracic aorta to transmural neural stimulation and norepinephrine were studied in relationto the presence or absence of cocaine, desipramine, pyrogallol and pheni-prazine. Cocaine in concentrations of 10 and 3 X 10 M progressively increased the ampli-tude and the duration (duration at the level of the half-maximum tension) of vascular con-traction induced by transmural stimulation; the prolongation of the duration exceeded greatly the tension increment. The contractile response was markedly reduced or completely abolished in vessels subjected to prolonged cold storage. Cocaine potentiated the contractile response when it was still retained but did not restore the response when abolished com-pletely. Desipramine caused a dual effect on vascular contraction induced by tranamural stimulation and norepinephrine; the contractile response was potentiated at 2 X 10 M des-ipramine but inhibited at 10 M. On the other hand, the duration of contraction was pro