Tegumental Ca-stimulated adenosine triphosphatase activity in adult Schistosoma mansoni worms

Memórias do Instituto Oswaldo Cruz

Italo M. Cesari²  Elis Aldana²  Francisco Gil²  Madalina Condrescu¹ 

[1] ,Instituto Venezolano de Investigaciones Científicas Centro de Microbiología y Biología Celular Laboratorio de Inmunoparasitología y Servicio de Microscopía ElectrónicaCaracas,Venezuela

关键词: Schistosoma mansoni;    tegumental membranes;    discoid bodies;    Ca-ATPase;    Calmodulin;    NAP-taurine inhibition;    chlorpromazine inhibition;    Schistosoma mansoni;    membranas tegumentárias;    corpos discóides;    Ca-ATPase;    calmodulina;    inibição de NAP;    taurina;    inibição de cloropromazine;   

DOI  :  10.1590/S0074-02761989000300005

来源: SciELO

【 摘 要 】

A Ca-stimulated ATPase activity (pH 9.5) associated with the tegumental membrane enriched (TME) fraction of Schistosoma mansoni adults was partially inhibited by NAP-taurine or by increasing concentrations of chlorpromazine; endogenous calmodulin was found associated with the TME fraction. A similar activity (pH 8.6) was histochemically visualized whithin the tegument of fixed worms on the cytoplasmic leaflet of both the doubel surface membrane and the basement membrane; this reaction was inhibited by 1 µM chloropromazine and it was also observed on the inner side of double membrane vesicles present in the TME fraction. No ATPase activity could be seen at alkaline pH with added Mg or Na/K ions. Without ATP, the addition of external Ca to the fixed worms induced the appearance of lead precipitates on the tegumental discoid bodies; this reaction was inhibited by molybdate and not by chlorpromazine. The intrategumentary regulation of calcium by the systems described and the possible use of phenothiazines against schistosimes are discussed.

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