Journal article
Temporal changes in intestinal Na +, K +-ATPase activity and in vitro responsiveness to cortisol in juvenile chinook salmon
Comparative biochemistry and physiology. Part A, Molecular & integrative physiology, Vol.138(3), pp.297-303
2004
Handle:
https://hdl.handle.net/2376/108725
PMID: 15313483
Abstract
Seasonal changes in endogenous Na
+, K
+-ATPase activity were measured in pyloric ceca and posterior intestine of juvenile chinook salmon (
Oncorhynchus tshawytscha) maintained in fresh water over 18 months. In tissues from these same fish, the in vitro responsiveness of Na
+, K
+-ATPase activity to 10 μg cortisol/ml was assessed. There were pronounced increases in endogenous Na
+, K
+-ATPase activity in summer for both intestinal regions, in underyearlings and yearlings. In pyloric ceca, a significant positive response of Na
+, K
+-ATPase activity to cortisol, in vitro, was restricted to the months preceding increases in endogenous Na
+, K
+-ATPase and the month afterward. Na
+, K
+-ATPase activity of the posterior intestine was only responsive to cortisol in underyearlings in the period before the peak in endogenous enzyme activity. At a time when explants were responsive to cortisol, in vitro exposure to 0.1–10 μg cortisol/ml resulted in dose-dependent elevations of Na
+, K
+-ATPase activity over controls (0 μg cortisol/ml). The results show that the intestine exhibits increased enzymatic potential for water absorption that is indicative of parr–smolt transformation. Alterations in tissue responsiveness to cortisol may contribute to these changes in Na
+, K
+-ATPase activity of pyloric ceca.
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Details
- Title
- Temporal changes in intestinal Na +, K +-ATPase activity and in vitro responsiveness to cortisol in juvenile chinook salmon
- Creators
- Philip A Veillette - Department of Zoology, University of Otago, P.O. Box 56, Dunedin, New ZealandGraham Young - Department of Zoology, University of Otago, P.O. Box 56, Dunedin, New Zealand
- Publication Details
- Comparative biochemistry and physiology. Part A, Molecular & integrative physiology, Vol.138(3), pp.297-303
- Academic Unit
- UNKNOWN
- Publisher
- Elsevier Inc
- Identifiers
- 99900547235901842
- Language
- English
- Resource Type
- Journal article