CROSS-REACTIVITY STUDIES OF CRF-RELATED PEPTIDES ON INSECT MALPIGHIANTUBULES

Manduca sexta diuretic peptide II (Mas-DPII) stimulates fluid secretio n by adult Malpighian tubules and cyclic AMP production by larval prox imal and adult tubules of M. sexta in a dose-dependent manner. Mas-DPI I has no effect on fluid transport across the larval cryptonephric com plex. M. sexta diuretic hormone (Mas-DH) and CRF-related insect diuret ic peptides from Acheta domesticus, Locusta migratoria, and Periplanet a americana also cause similar increases in the production of cyclic A MP by the Malpighian tubules of both larval and adult M. sexta. Insect CRF-related diuretic peptides exhibit varying degrees of potency when assayed on Malpighian tubules from L. migratoria and A, domesticus, S auvagine, bovine-CRF, and human-CRF have only a small, but significant , effect on cyclic AMP production by M. serta Malpighian tubules, Howe ver, sauvagine, bovine-CRF, and sucker fish urotensin-I have no effect on L. migratoria tubules, Stimulation of cyclic AMP production by M. serta Malpighian tubules could potentially be used as a screening assa y to identify other insect CRF-related diuretic peptides.