Vacuolar-Type H^+-ATPase and Na^+, K^+-ATPase Expression in Gills of Atlantic Salmon (Salmo salar) during Isolated and Combined Exposure to Hyperoxia and Hypercapnia in Fresh Water(Physiology)

概要

論文の詳細を見る
Changes in branchial vacuolar-type H^+-ATPase B-subunit mRNA and Na^+, K^+-ATPase α- and β-subunit mRNA and ATP hydrolytic activity were examined in smelting Atlantic salmon exposed to hyperoxic and/or hypercapnic fresh water. Pre-smolts, smolts, and post-smolts were exposed for 1 to 4 days to hyperoxia (100% O_2) and/or hypercapnia (2% CO_2). Exposure to hypercapnic water for 4 days consistently decreased gill vacuolar-type H^+-ATPase B-subunit mRNA levels. Salmon exposed to hyperoxia had either decreased or unchanged levels of gill B-subunit mRNA. Combined hyperoxia+hypercapnia decreased B-subunit mRNA levels, although not to the same degree as hypercapnic treatment alone. Hyperoxia generally increased Na^+, K^+-ATPase α- and β-subunit mRNA levels, whereas hypercapnia reduced mRNA levels in presmolts (β) and smolts (α and β). Despite these changes in mRNA levels, whole tissue Na^+, K^+-ATPase activity was generally unaffected by the experimental treatments. We suggest that the reduced expression of branchial vacuolar-type H^+-ATPase B-subunit mRNA observed during internal hypercapnic acidosis may lead to reduction of functional V-type H^+-ATPase abundance as a compensatory response in order to minimise intracellular HCO_3^- formation in epithelial cells.
社団法人日本動物学会の論文
2001-12-10