Measures of Resting Immune Function and Related Ph

Authors: M R van den Heuvel K O’Halloran R J Ellis N Ling M L Harris

Publish Date: 2005/03/28

Volume: 48, Issue: 4, Pages: 520-529

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Abstract

Juvenile rainbow trout Oncorhynchus mykiss were exposed to 0 10 30 and 70 v/v of a secondarytreated integrated thermomechanicalbleached kraft pulp and paper mill effluent The immunological parameters oxidative burst and phagocytosis of head kidney macrophages and total and differential circulating leukocytes were measured after 21 d of exposure General parameters of stress and exposure including erythrocyte counts numbers of degenerating erythrocytes splenic pigmented macrophage aggregates PMAs spleen size bile chemistry and hepatic EROD activity were also assessed Contrary to parallel chronic studies on the same effluent EROD induction did not occur Analyses of bile indicated uptake and accumulation of resin acids and some sterols There was no measurable macrophagerelated immunological dysfunction However circulating leukocytes specifically lymphocytes were reduced The density of splenic PMAs increased over the exposure period possibly in association with degenerating blood cells There were statistical differences between staggered days of sampling in head kidney oxidative burst white and mature red blood cell counts and spleen size indicating that relatively minor capture and handling stress could result in rapid changes in some parameters Overall it was concluded that the observed minor indirect alterations in the immune response were likely the result predominantly of a nonspecific mechanism such as a cortisolmediated stress responseFunding for this research was provided by the Foundation for Research Science and Technology FRST of New Zealand and by Norske Skog/CHH Tasman Mill formerly Fletcher Challenge Paper The authors thank Faye Hodgetts Murray Smith Rob Donald and Rob Hunter for their assistance

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