title: AedesCAPA-PVK-1 displays diuretic and dose dependent antidiuretic potential in the larval mosquito Aedes aegypti (Liverpool).
abstract: This study reveals that AedesCAPA-PVK-1 (GPTVGLFAFPRV-NH(2)) inhibits basal and serotonin stimulated fluid secretion in the Malpighian tubules of larval Aedes aegypti at femtomolar concentrations. Conversely 10(-4)moll(-1) of the peptide stimulated fluid secretion rates. The diuretic effects of 10(-4)moll(-1)AedesCAPA-PVK-1 and antidiuretic effects of 10(-15)moll(-1)AedesCAPA-PVK-1 were abolished by protein kinase A (PKA) and protein kinase G (PKG) inhibition, respectively. Similar to the peptide, 10(-3)moll(-1) cGMP stimulated fluid secretion but doses in the micromolar to nanomolar range inhibited fluid secretion of the Malpighian tubules. Stimulatory effects of cGMP were abolished by PKA inhibition and inhibitory effects of cGMP were abolished by PKG inhibition. Furthermore, the nitric oxide synthase inhibitor l-NAME attenuated the inhibitory effects of AedesCAPA-PVK-1 but did not affect inhibition by cGMP. Based on the results we propose that AedesCAPA-PVK-1 inhibits fluid secretion rates of larval Malpighian tubules via the NOS/cGMP/PKG pathway and that high doses of the peptide lead to diuresis through the cGMP mediated activation of PKA.
authors: Department of Biology, York University, 4700 Keele Street, Toronto, ON, Canada M3J 1P3.
authors: Adrian
authors: A
authors: Ionescu
authors: Andrew
authors: A
authors: Donini
mesh_terms: D000330:Aedes / Q000378:metabolism*; D000818:Animals; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism; D006152:Cyclic GMP / Q000494:pharmacology; D005260:Female; D007814:Larva / Q000378:metabolism; D008317:Malpighian Tubules / Q000378:metabolism*; D045283:Natriuretic Agents / Q000494:pharmacology / Q000502:physiology*; D009479:Neuropeptides / Q000494:pharmacology / Q000502:physiology*; D015290:Second Messenger Systems; D014882:Water-Electrolyte Balance
chemical_list: D045283:Natriuretic Agents; D009479:Neuropeptides; C093061:periviscerokinin; D017868:Cyclic AMP-Dependent Protein Kinases; D006152:Cyclic GMP