Amiloride-Sensitive Sodium Flux and Potentials in Perfused Carcinus Gill Preparations

• DOI: 10.1242/jeb.122.1.25
• Publication Date: 2021-04-26T00:02:54Z
• Authors: Čedomil Lucu; Dietrich Siebers
• Keywords: Amiloride; Hyperpolarization

ABSTRACT Sodium and chloride fluxes, as well transbranchial potentials (TBP) were studied in isolated perfused gill filaments of the crab Carcinus mediterraneus. Experiments carried out media that either hyposmotic to perfusion solution (asymmetrical conditions) or isosmotic (symmetrical conditions). Fluxes found be diffusional gills under asymmetrical conditions; amiloride induced an inhibitory effect on influxes, without affecting TBP. Under symmetrical conditions, TBP was −7·6 ±2·3 mV, suggesting electrogenic ion pump contributes significantly development Immediately after addition 2·5 × 10−4mol l−1 external solution, sodium influxes reduced 31% those control group, hyperpolarized from −14·8 mV. The absence Ca2+ conditions diminished hyperpolarization. Half-maximal inhibition by at 7× 10−5 mol 1-1. This low affinity is typical resistance leaky epithelia. transport discussed amiloride-affected influx, probably a Na/H antiport.