The Effect of Zymosan and Glucan On the Reticuloendothelial System and On Resistance To Traumatic Shock

Abstract

A study was made of the effects of 3 cell wall extracts of the yeast Saccharomyces cerevisiae on the reticuloendothelial system (RES) of the rat and the response to subsequent tumbling trauma. Zymosan, a whole cell wall extract, glucan, a pure polysaccharide component of zymosan and a lipid-free extract of zymosan all induced marked RE stimulation at different regimens. This stimulation was manifested by increase in weights of the spleen, liver and lung, striking proliferation of the RE cellular elements and pronounced heightening of the clearance rates of colloidal carbon in both the intact rat and the in situ perfused liver. Zymosan notably reduced shock mortality at 3 injection regimens but was ineffective at 3 others; neither glucan nor the lipid-free extract lowered shock mortality at any of the regimens tested. The results indicate that hyperplasia of the RES and increased carbon clearance activity are not adequate per se to confer protection against traumatic shock in the rat; they suggest that the shock-protective action of zymosan involves the lipid fraction.