BIOCHEMICAL AND MORPHOLOGICAL PATHOLOGY OF THE FOOT OF THE SCHISTOSOME VECTOR BIOMPHALARIA-GLABRATA INFECTED WITH SCHISTOSOMA-MANSONI

Infection by Schistosoma mansoni resulted in morphological and biochem ical changes to the foot of its intermediate host, Biomphalaria glabra ta. Migration through, and emergence of cercariae from, the foot was o bserved and evidenced by lesions on the ciliated foot surface. This wa s accompanied by a significant decrease in the velocity of movement by infected individuals. In vivo P-31 NMR spectral analyses demonstrated that the foot of infected snails had a lower phosphoarginine (PA)/ade nosine 5' triphosphate (ATP) ratio than that of uninfected controls. M oreover, kinetic experiments, employing saturation transfer, demonstra ted the pseudo-first-order rate constant for the arginine kinase-catal ysed exchange reaction in the forward direction, that is, PA --> ATP w as decreased by infection. The reverse reaction was not observed by th e NMR methods used. PA was depleted upon exposure to hypoxic condition s suggesting its traditional role in preserving ATP level. Partly oxid ized metabolic end-products were not observed in snails maintained und er aerobic conditions, but succinate, propionate, acetate and lactate rapidly accumulated under hypoxic conditions.