The Gill ATPase Assay

What is the ATPase assay?

Na+ K+ ATPase is an enzyme located on the membranes of cells.  One of its functions is to control levels of Na+ and Cl- ions entering and leaving the cells.  During the salmon parr-smolt transformation, gill ATpase activity increases between two and five-fold, to prepare the fish for exposure to higher concentrations of Na+ and Cl-.  Measuring the increase in ATPase activity is therefore an accurate and fast indicator of smoltification and a way of determining if farmed salmon are ready for transfer.

The ATPase assay has advantages over the saltwater challenge test

The saltwater challenge test is commonly used to assess whether fish are ready for transfer from freshwater to seawater.  Plasma ions are analysed in the fish after a 24 hour saltwater challenge.

The saltwater challenge test is however, prone to inaccuracies and the fish are exposed to stress during transportation to the challenge site and during the challenge itself.

The ATPase assay is an alternative to the saltwater challenge test and minimises stress on the fish, giving more accurate results within a shorter time-frame.

For further information please contact:
Dr Michael Williams - Analytical Services Technical Manager Tel: 01631 720765
or by email: michael.williams@integrin.co.uk