Immunolocalisation of NHE3‐like immunoreactivity in the gills of the rainbow trout ( Oncorhynchus mykiss ) and the blue‐throated wrasse ( Pseudolabrus tetrious )

Abstract

Na + /H + exchange has been implicated in models of ion transport across the branchial epithelium of marine and freshwater fishes. In this preliminary study, we present immunohistochemical data using a polyclonal antibody raised against NHE3 which show NHE3‐like immunoreactivity (IR) in the gills from a freshwater and a marine teleost species. In both species, branchial epithelial cells demonstrating NHE3‐like IR were localised predominantly to the junction between the filament and the secondary lamellae. However, there was a marked difference in the morphology of the NHE3‐like immunoreactive epithelial cells between the species. This morphological difference between the species suggests functional differences in the exchanger, which may be related to marine versus freshwater environments.