title: Glucocorticoid-induced glucose release is abolished in trout hepatocytes with elevated hsp70 content.
abstract: The metabolic potential of cells with elevated heat shock protein 70 (hsp70) content was examined by measuring unstimulated and glucocorticoid-stimulated glucose release in trout hepatocytes maintained in primary culture. Exposure of hepatocytes to either heat shock (HS;+15 degrees C) or sodium arsenite (50 microM) did not affect cell viability, but resulted in significantly higher hsp70 levels over a 24 h recovery period. Hsp70 accumulation had no significant impact on unstimulated glucose release, but completely abolished cortisol-induced glucose release in trout hepatocytes. This lack of glucocorticoid responsiveness corresponded with lower glucocorticoid receptor protein levels. Together, our results suggest that stressor-induced hsp70 accumulation, while important for maintaining cellular homeostasis, may impair metabolic adjustments to subsequent stressors in animals, especially those that are glucocorticoid-dependent.
authors.affiliation: Department of Biology, University of Waterloo, Waterloo, Ontario, N2L 3G1 Canada.
authors.forename: A N
authors.initials: AN
authors.lastname: Boone
authors.forename: B
authors.initials: B
authors.lastname: Ducouret
authors.forename: M M
authors.initials: MM
authors.lastname: Vijayan
mesh_terms: D000818:Animals; D018053:Arsenites / Q000378:metabolism; D015153:Blotting, Western / Q000379:methods; D002478:Cells, Cultured; D004591:Electrophoresis, Polyacrylamide Gel; D005947:Glucose / Q000032:analysis / Q000378:metabolism*; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism*; D006854:Hydrocortisone / Q000494:pharmacology*; D007770:L-Lactate Dehydrogenase / Q000032:analysis; D008099:Liver / Q000378:metabolism*; D017686:Oncorhynchus mykiss / Q000378:metabolism*; D011965:Receptors, Glucocorticoid / Q000378:metabolism
chemical_list: D018053:Arsenites; D018840:HSP70 Heat-Shock Proteins; D011965:Receptors, Glucocorticoid; D007770:L-Lactate Dehydrogenase; D005947:Glucose; C015001:arsenite; D006854:Hydrocortisone