EFFECTS OF NEUROPEPTIDE-Y ON LUNG VASCULAR-PERMEABILITY IN THE PULMONARY CIRCULATION OF RATS

The effects of neuropeptides on the capillary filtration coefficient i n the vessels of the pulmonary circulation were examined, using isolat ed lung perfusion preparations from rats. Neuropeptide Y and neurokini n A elevated the filtration coefficient, and calcitonin gene related p eptide diminished it. Neurotensin and substance P did not affect the v alue at concentrations less than 10(-7) M. The number of extravasated carbon particle deposits subsequent to tracheal application of neurope ptide Y during spontaneous respiration increased in a dose-dependent m anner. From these results, we conclude that neuropeptide Y may increas e vascular permeability in the pulmonary circulation.