A comparison of fatty acid patterns of arterial plasma, pericardial fluid and cardiac lymph in dog.

The fatty acid composition of cardiac lymph and pericardial fluid in anesthetized open-chest dogs, was analysed and compared with that of arterial plasma. The fatty acid content of triglyceride (TG) and total fatty acid fractions of pericardial fluid and cardiac lymph was significantly lower than that of plasma. On the other hand, free fatty acid (FFA) concentrations of pericardial fluid, cardiac lymph and plasma were not significantly different. The FFA fraction of cardiac lymph contained relatively more stearic acid and less oleic acid whereas, in plasma, the FFA fraction contains less myristic acid. The data are consistent with the hypothesis that endothelial permeability is a limiting factor for the transvascular exchanges of large molecules such as TG and that the FFA distribution in intersititial spaces may have been modified by the contribution of fatty acids from endogenous cardiac reserves or from the hydrolysis of plasma TG.