Isolation and Structure of the Hypertrehalosemic Hormone from Blaberus Discoidalis Cockroaches

Abstract

Trehalose is the major carbohydrate in most insects and its hemolymph concentrations are influenced by neuroendocrine factors from the corpora cardiaca (CC). In 1961, Steele first reported that CC extracts stimulated increased levels of hemolymph trehalose in the cockroach, Periplaneta americana (Steele, 1961). This phenomena was quickly confirmed in the tropical cockroach, Blaberus discoidalis (Bowers and Friedman, 1963). Since then, neuroendocrine effects were discovered in locusts, blowflies, stick insects, hornworm moths and others. Recently, two cardioaccelerator factors from P., americana were isolated and their structures confirmed by synthesis. These factors also have hyperglycemic activity (Scarborough et al., 1984). Further studies showed that these factors were the major hyperglycemic activity in CC extracts of P. americana. Each of these peptides are related to the structure of locust adipokinetic hormone (AKH1) and Crustacean pigment concentration hormone (RPCH). In this report, we describe the isolation and structure for the hypertrehalosemic hormone (HTH) from the cockroach, B. discoidalis, one of the first two insects in which this effect was identified.