Abstract
The corpora cardiaca of the cockroach Nauphoeta cinerea contain a hypertrehalosaemic hormone (HTH) which is chemically characterized as a blocked decapeptide. The synthetic HTH shows the same chromatographic behaviour as the material isolated from corpora cardiaca. The synthetic peptide causes hypertrehalosaemia and fat body glycogen phosphorylase-activation in N. cinerea as well as in the American cockroach, Periplaneta americana in a dose-dependent fashion. It is calculated that one gland from N. cinerea stores about 50 pmol of HTH. Roughly 10% of the total available hormone in the gland is released in vitro during exposure to an elevated potassium saline which causes depolarization of the neurosecretory cells