Continuous enteral nutrition attenuates pulmonary edema in rats exposed to100% oxygen

Adult rats exposed to hyperoxia develop anorexia, weight loss, and a lung i njury characterized by pulmonary edema and decreased lung liquid clearance. We hypothesized that maintenance of nutrition during hyperoxia could atten uate hyperoxia-induced pulmonary edema. To test this hypothesis, we enteral ly fed adult male Sprague-Dawley rats via gastrostomy tubes and exposed the m to oxygen (inspired O-2 fraction >0.95) for 64 h. In contrast to controls , enterally fed hyperoxic animals did not lose weight and had smaller pleur al effusions and wet-to-dry weight ratios (a measure of lung edema) that we re not different from room air controls. Enterally fed rats exposed to hype roxia had increased levels of mRNA for the Na+-K+ ATPase alpha (1)- and bet a (1)-subunits and glutathione peroxidase. These findings suggest that main tenance of nutrition during an oxidative lung injury reduces lung edema, pe rhaps by allowing for continued expression and function of protective prote ins such as the Na+-K+-ATPase.