Glucose-induced modulation of nutrient influx in Schistosoma mansoni

The tegumental influx of adenine, adenosine, arginine, choline, histidine, and lysine has been measured in mated and separated male and female Schistosoma mansoni 7-10 wk postinfection. Tissue uptake indices were measured after a brief rinse in either 5 mM glucose or glucose-free saline. Data indicate that schistosomes respond rapidly to this 2-3-sec exposure to glucose-free medium, and lowered uptake rates are observed. Similar studies, measuring cytosine and lysine uptake in Schistosoma japonicum indicate that, in this species also, reduced nutrient influx is seen after a transient exposure to glucose-free medium. It is proposed that these metabolites are not taken up by active transport processes, but rather the effect observed is the consequence of a rapid change in glucose metabolism.