Cockroach diuretic hormones: Characterization of a calcitonin-like peptide in insects

Insect diuretic hormones are crucial for control of water balance. We isolated from the cockroach Diploptera punctata two diuretic hormones (DH). Dippu-DH31 and Dippu-DH46, which increase cAMP production and fluid secretion in Malpighian tubules of several insect species. Dippu-DH31 and -DH46 contain 31 and 46 amino acids, respectively. Dippu-DH46 belongs to the corticotropin-releasing factor (CRF)-like insect DH family, whereas Dippu-DH31 has little sequence similarity to the CRF-like DH, but is similar to the calcitonin family. Dippu-DH46 and -DH31 have synergistic effects in D. punctata but have only additive effects in Locusta migratoria. Dippu-DH31 represents a distinct type of insect DH with actions that differ from those of previously identified insect peptides with diuretic activity.