HEAT-SHOCK-PROTEIN (HSP70) IN BROWN TROUT EPIDERMIS AFTER SUDDEN TEMPERATURE RISE

So far, hsp70 has not yet been studied in the fish skin. This organ ha s a potential as an indicator organ and we investigate whether hsp70 c ould be used as a biomarker. In this study, we examined whether and ho w the epidermis reacts to a temperature rise. Brown trout, Salmo trutt a fario, were exposed to higher temperature for 2 h and were allowed t o recover subsequently. Samples were taken from controls, after heat s hock, as well as after 24 and 48 h of recovery. The occurrence of hsp7 0 in trout skin was examined by Western blot. The amount of hsp70 was higher after 2-h heat shock and was rising until the end of the experi ment. Immunocytochemically, hsp70 was detected in epidermal filament c ells. After 2-h heat shock, hsp70 was predominantly located in the nuc leus. At this lime, light and electron microscopy revealed several fea tures known to occur under a variety of stressors. Ultrastructurally, the appearance of compact filament aggregates in pavement cells was re markable. After 24 h of recovery, filament compaction was lacking and after 48 h aspects of regeneration were obvious. However, an increased amount of apoptotic cells in the epidermis was prominent at this time only. (C) 1998 Elsevier Science Inc. All rights reserved.