ABSTRACT
Pulmonary surfactant is routinely obtained by lavaging the lungs several times with saline, followed by centrifugation at low speeds to remove cells and at higher speeds to obtain a white pellet of crude surfactant. Phosphatidate cytidylyltransferase, the enzyme responsible for the formation of CDP-diacylglycerol, has been studied in lung microsomal and mitochondrial fractions. Phosphatidate phosphohydrolase was first described in plants by Kates in 1955. The potential role of phosphatidate phosphohydrolase in the regulation of the production of diacylglycerol for surfactant PC prompted a comparative study on the properties of this hydrolase and phosphatidylglycerophosphate phosphohydrolase. The effect of chlorpromazine on the phosphatidate phosphohydrolase activities in rat lung microsomes and cytosol was clarified using a similar approach. The rediscovery of the pulmonary surfactant system by Pattle and Clements soon inspired Avery and Mead to investigate the possibility that the absence of surfactant, as opposed to the presence of hyaline membranes, was responsible for the initiation of this disease in the neonate.
