Regulation of cockroach fat-body metabolism by the corpus cardiacum in vitro.

Incubation in vitro of young, adult, male Leucophaea maderae fat body with extracts of corpora cardiaca or intact corpora cardiaca results in stimulation of oxygen consumption but reduction in carbon dioxide evolved from carbohydrate. The carbohydrate is preferentially used for trehalose synthesis, and the endogenous metabolism of the fat body appears to be supported by increased lipid utilization. A hormone from the corpus cardiacum is most likely responsible for these effects and may act at two points, at least, in the glycolytic pathway.