PHYSIOLOGICAL EFFECTORS OF HYPERGLYCEMIC NEUROHORMONE BIOSYNTHESIS INAN INSECT

Biosynthesis of hypertrehalosemic hormone (HTH) by isolated corpora ca rdiaca (CC) from Blaberus discoidalis cockroaches was measured for the S-week period following adult ecdysis using an in vitro bioassay base d on the incorporation of [H-3]tryptophan. Synthetic rates for both ma les and females were highest following the molt and declined with age. Rates of HTH secretion and levels of stored HTH followed a similar pa ttern. We found no neural or endocrine brain effects or photophase inf luence on HTH synthesis. Synthesis was unaffected by treatment with 20 -hydroxyecdysone or the juvenile hormone analog methoprene. In starved insects, HTH synthesis doubled and secretion increased 66% relative t o fed controls.