Metabolism of hookworms. II. Glucose metabolism and glycogen synthesis in adult female Ancylostoma caninum

The oxygen consumption of starved adult female Ancylostoma caninum is not stimulated by the addition of 0.1% glucose to Krebs-Ringer bicarbonate in which they were incubated, nor is the added glucose metabolized by them. Under these conditions, they metabolize their endogenous glycogen, and the R.Q. is approximately 1. Experiments with glucose-C14 show that a small amount of glucose from the Krebs-Ringer bicarbonate is metabolized and incorporated into the parasite's glycogen. A high oxygen tension is found to depress this process. When incubated in dog serum, however, the parasite is found to take in a considerable amount of glucose, and the amount of glycogen that is labeled is 10 times that of worms incubated in Krebs-Ringer bicarbonate under similar conditions. The nondiffusible fraction of dog serum obtained by dialysis is mainly responsible for this enhancing effect on the incorporation of glucose from the external medium into the glycogen of A. caninum. These findings are discussed.