[Histochemical aspects of liver lesions induced in hamsters by inoculation of E. histolytica in axenic culture. II. Evidence of perinecrotic fibrosis].

The percutaneous, intrahepatic inoculation of E. histolytica trophozoites in weanling hamsters produced lesions of various shapes and sizes. The time-span between inoculation and sacrifice did not correlate with the size of the lesions. Histoenzymologic technics for acid and alkaline phosphatases, adenosinetriphosphatase (ATPase) and glucose-6-phosphate dehydrogenase (G-6-P DH) showed that the necrotic material is positive to the two former phosphatases whereas ATP-ase shows distorted bile canaliculi due to profound parenchymal alterations and the presence of G-06-P DH activity in parenchyma as well as its lack of activity in necrotic material suggests that the pentose cycle is involved in the genesis of the lesion. The presence of collagen fibers surrounding the lesions suggests that during the expansion of the lesions, there is a granulomatous inflammatory stage with fibrosis immediately followed by fibrinolysis. Four zones can be distinguished in an expanding lesion: necrosis, a zone of junction between necrosis and parenchyma which depicts a crown of invasive trophozoites surrounding the necrosis, a histiocytic halo and a zone of peripheral necrosis.