In cockroaches and certain other insects the concentration of trehalose in the hemolymph is increased by hypertrehalosemic hormone (HTH), a neuropeptide originating in the corpus cardiacum. A vital step in the action of HTH to promote conversion of glycogen stored in the fat body to trehalose is the activation of phosphorylase. The means by which HTH activates phosphorylase, with particular emphasis on its role in the regulation of intracellular calcium, is discussed. Additional information supporting the view that HTH stimulated synthesis of trehalose, and possibly its release from the trophocyte, is regulated by fatty acids and eicosanoids is presented., John E. Steele, and Lit
The occurrence of melatonin is known in nearly all organisms, but nothing is known exactly about its function outside of vertebrates. Long-term perifusions as well as short-term batch incubations of brains and moulting glands of the cockroach Periplaneta americana were used to identify the effect of melatonin on the release of prothoracicotropic hormone, a glandotropic neuropeptide in the brain, which stimulates the production of the moulting hormone ecdysone in the moulting gland. This is the first experimental evidence of a neurohormonal releasing effect of melatonin in the insect nervous system., Klaus Richter, Elmar Peschke, Dorothee Peschke, and Lit