Transepithelial potential differences and Na+ flux in isolated perfused gills of the crab Chasmagnathus granulatus (Grapsidae) acclimated to hyper- and hypo-salinity
We studied the transepithelial potential difference (TEPD) and 22Na flux across isolated perfused gills (anterior pair 5 and posterior pairs 6-8) of the crab Chasmagnathus granulatus acclimated to either hypo- or hyper-osmotic conditions. The gills of crabs acclimated to low salinity, perfused and b...
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| Autores principales: | , , |
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2002
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00220949_v205_n1_p71_Luquet http://hdl.handle.net/20.500.12110/paper_00220949_v205_n1_p71_Luquet |
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| Sumario: | We studied the transepithelial potential difference (TEPD) and 22Na flux across isolated perfused gills (anterior pair 5 and posterior pairs 6-8) of the crab Chasmagnathus granulatus acclimated to either hypo- or hyper-osmotic conditions. The gills of crabs acclimated to low salinity, perfused and bathed with 10%‰ saline solutions, produced the following TEPDs (hemolymph side with respect to bath side): 0.4±0.7, -10.2±1.6, -10.8±1.3 and -6.7±1.3mV for gills 5, 6, 7 and 8, respectively. Gills 6, 7 and 8 did not differ significantly. Reducing the saline concentration of bath and perfusate from 30%‰ to 20%‰ or 10%‰ increased significantly the TEPDs of these gills. TEPDs of gill 6 (representative of posterior gills) were reduced by 69±5% and 60±5% after perfusion with ouabain or BaCl2 (5mmoll-1 each), respectively. The same gill showed a net ouabain-sensitive Na+ influx of 1150±290 μequiv g-1h-1. Gill 6 of crabs acclimated to high salinity produced TEPDs of -1.5±0.1 and -1.3±0.09mV after perfusion with 30%‰ or 40%‰ salines, respectively. Perfusion with ouabain or BaCl2 reduced TEPDs by 76±7% and 86±4%, respectively. A net ouabain-sensitive Na+ efflux of 2282±337 μequiv g-1h-1 was recorded in gill 6 perfused with 38%‰ saline. |
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