Evidence for a humoral factor in vagotomy-induced pulmonary edema

¹ Department of Pharmacology, University of Utah College of Medicine, Salt Lake City, Utah

Two types of experiments were performed on unanesthetized guinea pigs: a) acute parabiotic union with common peritoneal cavity; and b) continuous cross circulation. Three combinations of animal pairs were employed in each type of experiment, grouped as follows: group 1, both partners were not vagotomized; group 2, both partners were vagotomized; group 3, one partner was vagotomized and its mate was not vagotomized. Lung-to-body weight ratio served as the index of pulmonary edema. In the parabiosis series, the vagotomized partner of group 3 was protected from edema by being joined with a nonvagotomized animal. In the cross-circulation series, the nonvagotomized partner of group 3 developed pulmonary edema as a result of being cross-perfused with a vagotomized animal. In both series, survival time of vagotomized animals was prolonged by their being juxtaposed to nonvagotomized animals. Interaction between vagotomized and nonvagotomized partners in parabiosis as well as in cross-circulation experiments is best explained by exchange of an edemagenic substance.