Diuretic hormone: another peptide with widespread distribution within the insect CNS

ABSTRACT. Diuretic hormone is a peptide neurohormone of as yet unknown chemical structure. Attempts to characterize the locust hormone have concentrated on the storage lobes of the corpora cardiaca as a source of material. Bioassay data now indicates that the occurrence of diuretic activity is more widespread in the locust CNS. Dose‐response curves indicate that the levels of the diuretic factor(s) in the brain, sub‐oesophageal and thoracic ganglia are remarkably similar to those found in the corpora cardiaca; activity was also detected in the abdominal ganglia (1–5) and terminal abdominal ganglion. Reverse‐phase HPLC has confirmed that the diuretic material found in the various parts of the CNS is chemically similar to at least one of the diuretic factors separated from the corpora cardiaca. The significance of the widespread distribution of this peptide hormone is considered. Recent evidence of other workers has indicated the possible structural similarity between vertebrate vasopressin and the diuretic factor in the locust sub‐oesophageal ganglion. Chromatographic criteria have been used to demonstrate that the diuretic hormones isolated in our work are not vasopressin‐like molecules, but are chemically distinct entities.