In vitro and in vivo effect of diethylcarbamazine on the activity of acetylcholinesterase from Wuchereria bancrofti infected human serum.

The acetylcholinesterase (AChE) activity was measured in human serum from persons infected with the filarial parasite Wuchereria bancrofti. The asymptomatic microfilaremic serum showed five times increase in AChE-activity as compared with normal serum, whereas only little difference was observed in serum from patients with elephantiasis. Similar results were obtained when the enzyme activity was measured in the immune complexes precipitated with polyethyleneglycol. Further, the effect of the antifilarial drug diethylcarbamazine (DEC), on the AChE activity of infected and normal serum was studied in in vivo and in vitro experiments. In vitro, DEC was found to be effective only with respect to AChE from asymptomatic microfilaremic serum where 75% decrease in enzyme activity was observed at 100 mumol. The oral administration of DEC (5 mg/kg of body weight/day) effected the activity of AChE from microfilaremic serum as shown after 1 hr, 1 and 3 weeks. A regular decrease in enzyme activity of asymptomatic microfilaremic serum was observed. By increasing time periods and after three weeks the level of AChE reaches the normal value. In vitro and in vivo the same concentration of DEC has negligible effect on the normal serum suggesting that in case of asymptomatic microfilaremic serum the increased activity of AChE is different in nature than the host acetylcho-[abstract incomplete in journal]