| | 1 | Author
| A.Ndreas Detzel, Michael Wink | Requires cookie* | | | Title
| Evidence for a Cardenolide Carrier in Oncopeltus fasciatus (Dallas) (Insecta: Hemiptera)  | | | | Abstract
| O ncopeltus fasciatus (H emiptera) is morphologically and physiologically adapted to seques ter cardiac glycosides for its chemical defence against predators. A s a prerequisite for carde nolide utilization this bug has to take up and store the dietary cardenolides. Using isolated midguts it could be shown experimentally that the resorption of [3H]digoxin is time-, and temperature-dependent. The hydrogen ion concentration for uptake is optimal between pH 5.5 and 7 and an activation energy of 45 to 49 kJ/mol can be derived from an Arrhenius plot. U ptake can be inhibited competitively by the polar cardiac glycoside convallatoxin. Sulf-hydryl group reagents (N-ethylmaleimide), membrane destabilizing compounds and respira tory chain inhibitors reduce digoxin resorption, as do inhibitors of sugar transport (e.g., phlo-ridzin). The experimental data thus provide evidence for a cardenolide carrier in midgut cells o f O. fasciatus. | | | |
Reference
| Z. Naturforsch. 50c, 127—134 (1995); received October 10/November 18 1994 | | | |
Published
| 1995 | | | |
Keywords
| O ncopeltus fasciatus, Chemical Defence, Cardenolide Sequestration, Carrier-Mediated Uptake, Cardenolide Carrier | | | |
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| default:Reihe_C/50/ZNC-1995-50c-0127.pdf | | | | Identifier
| ZNC-1995-50c-0127 | | | | Volume
| 50 | |
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