Schistosoma mansoni and/or its eggs cause important hepatic pathology distinguished by very characteristic anatomo-clinicalfeatures. If carried by the blood stream, the worms are able to occlude dichotomic branches of larger diameter of the portal system. These worms, when dead, produce lesions that are sometimes extensive, initially necrotic, then inflammatory and finally cicatricial. These lesions are always circumscribed and not systematized. Besides penetrating into the tiny non-dichotomic branches of the periductal net, the eggs reach the branches of distribution or even the afferent venulae, occluding some of them. Consequently intravascular granulomas are formed which can lead to an interruption of the portal blood stream at this level and to changes in the intralobular circulation. The decrease of the rate of available oxygen and consequent decrease in the intra and extracellular pH are potent labilisers of membranes of several components of the lysosomal compartment. The exit of acid hydrolases, cationic proteins and neutral hydrolases from these organelles brings about major tissular aggression, represented by the formation and maintenance of the typical inflammatory processes of this parasitism. In this work lysosomal activity related to hepatic schisto-somiasis mansoni has been studied. The results indicated that the functional integrity of the lysosomal membrane complexe had been significantly changed. These changes have been observed from the second month of infection and there seems to be a close relationship between the severity of the liver inflammatory lesions and a greater lysosomal lability.
Schistosomiasis mansoni; Hepatic lysosomal compartment; Lysosomal activity