Regulation of ion transport by pH and [HCO3−] in isolated gills of the crabNeohelice(Chasmagnathus)granulata

• DOI: 10.1152/ajpregu.00516.2007
• Publication Date: 2008-01-10T02:05:16Z
• Authors: Martin Tresguerres; Scott K. Parks; Sebastian E. Saba...; Greg G. Goss; Carlos M. Luquet
• Keywords: DIDS; Bafilomycin; Acetazolamide; Transepithelial potential difference; Amiloride; Acid–base homeostasis

Posterior isolated gills of Neohelice ( Chasmagnathus) granulatus were symmetrically perfused with hemolymph-like saline varying [HCO 3 − ] and pH. Elevating in the from 2.5 to 12.5 mmol/l (pH 7.75 both cases) induced a significant increase transepithelial potential difference V te ), measure ion transport. The elevation also switch acid secretion (−43.7 ± 22.5 μequiv·kg −1 ·h ) controls base (84.7 14.4 ). HCO -induced was inhibited by basolateral acetazolamide (200 μmol/l), amiloride (1 mmol/l), ouabain (5 mmol/l) but not bafilomycin (100 nmol/l). response did take place Cl -free conditions; however, it unaffected apical SITS (2 or DIDS mmol/l). A decrease pH 7.45 units perfusate , which matched net 67.8 18.4 μequiv kg h . This stimulation sensitive acetazolamide, bafilomycin, DIDS, Na + conditions, still took saline. Therefore, cellular low is different -stimulated response. We report V-H -ATPase- -K -ATPase-like immunoreactivity gill sections for first time this crab. Our results suggest that carbonic anhydrase (CA), /H exchangers -ATPase anion participate response, while CA, -dependent cotransporters mediate