Agar accumulates in rat peritoneal macrophages elicited with thioglycollate broth.

Thioglycollate broth- and agar-elicited rat peritoneal exudate cells contain copious amounts of agar, a sulphated polysaccharide contained in the eliciting agent; the agar content has been measured chemically by the anthrone method for neutral polysaccharides. Adherence experiments confirm that day-3 thioglycollate-elicited macrophages contain 95% of the measured agar; on day 1, 72% is associated with polymorphonuclear cells. Agar ingestion by macrophages coincides with increases in glycogen synthase activity. We suggest that ingestion of agar may be related to the reported deficiencies in function of thioglycollate-elicited or -treated macrophages.