Histopathological studies on suramin toxicity in a chimpanzee
Gibson, D.W.; Duke, B.O.; Connor, D.H.
Tropenmedizin und Parasitologie 28(3): 387-405
1977
ISSN/ISBN: 0303-4208 PMID: 910288 Document Number: 115572
A healthy 11-yr-old female chimpanzee was injected with a total suramin dosage of 152 mg/kg over 36 days. Towards the end of this treatment the animal became listless, remained prostrate in her cage, lost her appetite and became emaciated; she developed signs of hemorrhaging, chronic diarrhea, anemia, lymphocytopenia, albuminuria and granular casts in urine. She appeared to be on the verge of death and was killed on day 47 with an overdose of pentobarbital. An autopsy was performed, and histopathological studies were carried out. Primary target organs involved in suramin toxicity included the intestine, kidney, spleen and peripheral blood. The intestinal tract was hyperemic and swollen, with petechiae and ecchymoses. There was acute ulcerative colitis, with atrophy of the mucosa and regeneration of epithelial cells and acute suppurative enteritis, with phagocytosed hemosiderin in villi of the jejunum. The kidneys were pale, epithelial cells of the renal tubules were degenerating and tubules and Bowman's space contained proteinaceous material possibly a complex of suramin with albumin or other plasma proteins. The spleen was atrophic and contained large amounts of hemosiderin consistent with hemolytic anemia. EM revealed abnormal material within erythrocytes of the spleen possibly precipitates of suramin Hb complex. Changes in the liver and lymph nodes are believed to be secondary to suramin toxicity. There was no degeneration of the adrenal cortex. Observed toxicity may be related to known biochemical and pharmacological properties of suramin: it binds to albumin, Hb and other plasma proteins; is an anticoagulant and anticomplement, and inhibits a wide variety of enzymes such as proteases and ATPases.