Terpene-induced lowering of surface tension in vitro: a rationale for surfactant substitution

Various terpenes were spread in an in vitro approach on an artificial monolayer film of di-palmitoyllecithin and enriched natural pulmonary surfactant of rats; the initial surface pressures of these substrates were measured and the resulting surface pressure increment recorded. All terpenes used were able to decrease surface tension at the air/water interface. The out-coming data were used to fit a mathematical model showing that an increase in surface pressure can improve pulmonary function concerning the tidal volume. The in vitro results might be taken as a further rationale for surfactant substitution by appropriate molecules in vivo.