Effect of Splenectomy on ‘Antrycide’ Therapy of Trypanosoma evansi Infection in Rats

‘ANTRYCIDE’, a trypanocidal drug which has been reported to be inactive in vitro, exerts marked chemotherapeutic activity in vivo1. This difference in activity of ‘Antrycide’ in vitro and in vivo may possibly be due to the drug being converted to a more active metabolic degradation product than the parent drug, or activated in vivo through the intervention of the reticulo-endothelial system. The first of these possibilities cannot be excluded in the present state of knowledge, as very little is known about the metabolic degradation products of ‘Antrycide’. This communication presents evidence to support the latter view that the reticulo-endothelial system plays an important part in the chemotherapeutic activity of ‘Antrycide’ (methylsulphate salt) against T. evansi in rats. The strain of T. evansi is of equine origin, isolated at the Indian Veterinary Research Institute in 1945, and being maintained through blood passages in rats.