Effect of praziquantel on clinical-chemical parameters in healthy and schistosome-infected mice.

The response of hepatic and haemotopoetic functions to treatment with praziquantel was studied using healthy and schistosome-infected mice. Female CF1 mice harbouring an 18 week old infection with Schistosoma mansoni and healthy uninfected mice of the same age were orally treated with 1 x 250 mg praziquantel/kg. The respective uninfected controls received the vehicle only. Blood samples were taken one, five, 14 and 28 days after treatment. Parameters studied were: activity of GOT, GPT and AP, concentration of glucose, blood clotting time, haemoglobin content, erythrocyte and leucocyte counts, PCV and body weight. The data were analyzed to reveal the effect of the three independent variables involved: infection, treatment and time after treatment. Infection of mice with S. mansoni for 18 weeks resulted in a depression of body weight, in a decrease of plasma GOT activity and of PCV and in increases of plasma GPT and AP activities, leucocyte counts and clotting time. Plasma glucose concentrations remained unaffected. The effects of treament with praziquantel were confined to the infected group. Changes attributable to the variable time were also more pronounced or even restricted to the infected treated group. Treatment of infected mice with praziquantel resulted in a temporary elevation of plasma GOT and GPT activities on Day 1 after treatment. Values had returned to normal on Day 5. Treatment further resulted in a slight but prolonged elevation of AP activities, a high leucocyte count on Day 5 after treatment and a normalization of the underweight and anaemic state of the infected mice. The nature of the effects observed after treatment with praziquantel is discussed in the light of corresponding data on the effect of treatment with hycanthone and SQ 18.506 in schistosome infected mice and Mastomys. It is concluded that the changes observed can be regarded as secondary, reflecting host responses to damaged parasites and healing processes.