Increased susceptibility of hypersplenic rats to infection with pneumococci.

Hypersplenism was induced in rats by intra-peritoneal injections of methylcellulose. These rats developed an outsize spleen and had significantly depressed values for hemoglobin concentration, hematocrit and platelet count. The rats given methylcellulose were also found to be more susceptible to a challenge with a standardized intravenous injection of Streptococcus pneumoniae and had a significantly higher mortality rate than the control rats.