Electronic Thesis and Dissertation Repository


Master of Science




Dr. Ruud Veldhuizen


This thesis explored the effects of cholesterol and SP-A on surfactant function in vitro, and lung function in vivo. In the first experiment, we determined whether SP-A could mitigate cholesterol-mediated surfactant dysfunction. We hypothesized that SP-A can mitigate the surfactant inhibition caused by high cholesterol. In the second experiment, we tested the contribution of diet-induced serum hypercholesterolemia to surfactant composition and the development of lung injury in rats. We hypothesized that serum hypercholesterolemia would increase the amount of cholesterol in surfactant and would cause rats to develop more severe lung injury. Our results indicate that SP-A mitigates cholesterol-mediated surfactant inhibition; however, serum levels of cholesterol do not affect surfactant composition or the severity of lung injury. In conclusion, elevated cholesterol within surfactant represents a mediator of surfactant dysfunction which can impede proper lung function, but SP-A can mitigate this form of inhibition.