[Effect of the quality of various vegetable oil emulsions on phagocytotic activity of the reticuloendothelial system in the rat]

Abstract

In the liver, reticuloendothelial cells make up 35 p. 100 of the total cellular population. The characterization of the reticuloendothelial system (RES) is its phagocytic activity. Certain fatty acids and lipids produce stimulation or depression of phagocytic function. In the present study, the phagocytic activity of the RES has been evaluated 3 days after oral (15 g/kg) and intravenous (1, 5 g/kg) treatments of male rats with emulsions of peanut, canbra, soyabean, olive and rapeseed oils. The distribution of particle sizes of all suspensions were made microscopically. Phagocytic function was measured by the blood clearance of colloidal carbon injected intravenously; the phagocytic index was calculated from the formula: log C=Kt + log C0 where C and C0 were carbon concentrations in standard volumes of blood removed from the animals at times t and t0 (in minutes). Intravenous administrations with the 5 oil emulsions significantly increased the phagocytic function of the RES. However, with oral administration, stimulation or depression of phagocytic function were dependent of many factors, among them the nature of the oil and the physical and chemical structure of the lipid emulsion. The variations in particle sizes found in emulsions make it extremely difficult to draw any comparison between their effects on the RES phagocytic capacity of rat; but difference in the distribution of various particle sizes provided an indirect approach to studying their influences on RES stimulation or inhibition. However, it is obvious that although modifications of particle sizes may alter the level of phagocytic activity induced by certain oil emulsions, they do not explain the phenomenon. The activity of phagocytic function of oil emulsions on RES cells can be related to their physical or chemical properties; the mode of esterification of the fatty acids may be an important factor. However, no evidence has been obtained which in any way correlates changes in physical or chemical properties of the studied oil emulsions with the observed differences in effects upon the RES cells. No adequate explanation of the role of these parameters in the stimulation or inhibition of phagocytic properties of RES can be made and other studies are necessary.