Effects of nitroquine on sporogenic cycle of Plasmodium cynomolgi
Abstract
Having previously reported that nitroquine (CI-679) had a marked sporontocidal effect on P. gallinaceum, we studied its effects on sporogony of P. cynomolgi using Anopheles stephensi or A. balabacensis as vectors. After being fed on infected monkeys before and after a single intragastric dose of nitroquine, the engorged mosquitoes were maintained in the insectarium at 27—28℃ (for A. stephensi) or 25—27℃ (for A. balabacensis) and relative humidity of 80%. Batches of mosquitoes were dissected on d 6 and d 12 after blood feeding for examination of oocysts and sporozoites, respectively. For comparison, the effects of DDS and pyrimethamine were observed at the same time.
1. Batches of mosquitoes fed on 3 monkeys 4—96 h after ig nitroquine 2 mg/ kg, were all negative for sporozoites. The oocyst rates also markedly decreased. At 1 mg/kg, only 1 out of 4 monkeys gave a 10% sporozoite rate after 96 h. Nitroquine composite (nitroquine and DDS in equal amount) 0.5 mg/kg, like nitroquine 2 mg/ kg, completely inhibited the sporogonic development of P. cynomolgi.
2. A single ig nitroquine 1 mg/kg showed a marked sporontocidal effect while pyrimethamine 1 mg/kg failed to do so. DDS 1 mg/kg exerted no effect on the sporogonic cycle of P. cynomolgi.
3. The results indicate that nitroquine is an effective drug, even superior to pyrimethamine, against sporogonic cycle of P. cynomolgi.
Keywords:
1. Batches of mosquitoes fed on 3 monkeys 4—96 h after ig nitroquine 2 mg/ kg, were all negative for sporozoites. The oocyst rates also markedly decreased. At 1 mg/kg, only 1 out of 4 monkeys gave a 10% sporozoite rate after 96 h. Nitroquine composite (nitroquine and DDS in equal amount) 0.5 mg/kg, like nitroquine 2 mg/ kg, completely inhibited the sporogonic development of P. cynomolgi.
2. A single ig nitroquine 1 mg/kg showed a marked sporontocidal effect while pyrimethamine 1 mg/kg failed to do so. DDS 1 mg/kg exerted no effect on the sporogonic cycle of P. cynomolgi.
3. The results indicate that nitroquine is an effective drug, even superior to pyrimethamine, against sporogonic cycle of P. cynomolgi.