Effectiveness of aprotinin in blocking a hypotensive factor of pancreatic origin from the pig, dog and monkey

Minced pancreas or a collagenase solution alone had no effect on blood pressure when infused into experimental animals. However, collagenase digested fragments or the digested pancreatic supernatant (PSF) produces profound hypotension. Previously we have shown that aprotinin, a proteolytic enzyme inhibitor, successfully blocked PSF-induced hypotension in the pig but did not alter this hypotension in the dog or monkey. Species variability of aprotinin blockade was further investigated by infusing PSF from either the pig, dog, or monkey into five animals of the other two species ("across species"). PSF alone produced hypotension in every animal "across species" but PSF "across species" and in combination with aprotinin did not produce a hypotensive reaction in each "across species" combination. These species differences of the aprotinin blockade should be considered when seeking reasons why aprotinin has not proven effective in preventing the morbidity and mortality of human pancreatitis.