EFFECT OF CYCLOPHOSPHAMIDE ON THE ACQUISITION OF RESISTANCE TO INFESTATION BY RHIPICEPHALUS-APPENDICULATUS IN RABBITS

Parenteral administration of cyclophosphamide in rabbits made resistan t to infestation by the tick Rhipicephalus appendiculatus, resulted in abrogation of the resistance phenomenon. As a result, a high percenta ge (83%) of the larval ticks fed to repletion. This was in contrast to the control rabbits which were expressing the phenomenon of resistanc e to infestation by the ticks. In the latter, only 28% of the ticks fe d to repletion. Cyclophosphamide administration in rabbits induced a l eucopenia and depressed antibody response to the heterologous antigen, sheep red-blood cells.