Haemolytic anaemia in rhesus monkeys induced by methylcellulose

The rhesus monkey was evaluated in its haemopoietic and histological response to intraperitoneal injections of methylcellulose. The haematologic alterations included a mild haemolytic anaemia, lymphopaenia, monocytosis, a shortened survival of Cr51 -labelled autologous erythrocytes (17 . 1 vs 13 . 3 days, P less than 0.025) and normoblastic hyperplasia of the bone marrow. There was a diffuse sequestration of the polymer in the phagocytic cells of the spleen, liver, bone marrow, lymph nodes and adrenal glands. The renal glomerular endothelium also consistently stored this material. Overt splenomegaly was not induced. The monkey appears to present, along with other animals, a rather species-specific response to methylcellulose that is accompanied by fundamental responses observable in all subjects.