Dynamic changes of pulmonary pressure and flow following pressor vasoactive drugs intravenous injection

In acute experiments on the mongrel anesthetized cats it was shown that following intravenous injection of catecholamines pulmonary flow always increases, meanwhile pulmonary pressure (in the most of the experiments) can be increased or decreased. After epinephrine injection the values of pulmonary pressure were varied comparing with the pulmonary flow equal increases. Norepinephrine caused the different changes both of the pulmonary pressure and flow. Angiotensin intravenous injection evoked various (elevating or lowering) changes of the pulmonary flow. In these conditions the pulmonary pressure can be increased or decreased independently from the direction of the pulmonary flow shifts. Following intravenous injection of these pressor vasoactive drugs pulmonary pressure reaches its maximal levels and returns to the initial values earlier, than pulmonary flow does. Thus we concluded that in the case of intravenous injection of pressor vasoactive drugs linear correlation is not revealed between the direction of the shifts of the pulmonary pressure and flow, their values and the time of the maximal level and duration of their changes.