کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5922183 | 1165351 | 2012 | 8 صفحه PDF | دانلود رایگان |
This study reveals that AedesCAPA-PVK-1 (GPTVGLFAFPRV-NH2) inhibits basal and serotonin stimulated fluid secretion in the Malpighian tubules of larval Aedes aegypti at femtomolar concentrations. Conversely 10â4 mol lâ1 of the peptide stimulated fluid secretion rates. The diuretic effects of 10â4 mol lâ1AedesCAPA-PVK-1 and antidiuretic effects of 10â15 mol lâ1AedesCAPA-PVK-1 were abolished by protein kinase A (PKA) and protein kinase G (PKG) inhibition, respectively. Similar to the peptide, 10â3 mol lâ1 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.
Highlights⺠CAPA-PVK-1 has biphasic fluid secretion effects in larval Aedes aegypti. ⺠Low dose CAPA-PVK-1-induced NOS/cGMP pathway causes inhibition. ⺠High dose CAPA-PVK-1-induced cross talk between cGMP and PKA causes stimulation.
Journal: Journal of Insect Physiology - Volume 58, Issue 10, October 2012, Pages 1299-1306