[Dependence of the effect of vasodilator preparations on the initial distensibility of the vascular bed]

Acute experiments on anesthetized cats under extracorporeal circulation were made to study the effects of papaverine, phentolamine and dihydroergotamine on the blood flow-pressure relations of the vascular bed of the greater circulation. It was shown that the drug-induced change in the vascular resistance were dependent on the perfusion flow and on the initial distensibility of arterial vessels as well. A mathematical simulating model that permits fore-telling alterations in the vascular resistance is described.