EXPERIMENTALLY INDUCED RELEASE OF A NEUROHORMONE INFLUENCING HEMOLYMPH TREHALOSE LEVEL IN CALLIPHORA ERYTHROCEPHALA (DIPTERA)

Evidence is presented that the corpus cardiacum (c. card.) of the blowfly Calliphora is the source of a neurohormone, which in less than 20 min after stimulation may cause a significant rise in the hemolymph trehalose level in vivo. Assay is based on thin-layer chromatography of hemolymph samples from before and after the experiment for each individual fly, and the effect is recorded as the difference in size and density between the two spots, not as absolute trehalose amounts. Electrical stimulation, combined with various surgical experiments, has shown that the c. card. may be activated via the brain to release the hyperglycemic hormone, provided that the nerve connection between the brain and the c. card. (the cardiac-recurrent nerve") is intact. © 1969."