Influence of yeasts and of their constituents on nucleoside uptake in peritoneal murine macrophages

A marked reduction of [3H]‐uridine uptake was observed when mouse peritoneal macrophages (pMφ) were exposed to heat‐killed Candida albicans or Saccharomyces cerevisiae. By contrast, an increased nucleoside uptake was promoted by yeast products such as zymosan, laminarin, or yeast cell‐wall extracts, which are mainly composed of β‐glucans and α‐mannans. In a search for the active fungal component(s), the uptake process was shown ti be differently affected by monosaccharides and polysaccharides. These findings support the view that a specific recognition of a pMφ membrane receptor is mediating the effect of the various substances.