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Differential HSP expression between liver and quadriceps in response to chronic exertional heat stress
Author(s) -
Haak Jodie L,
Bloomer Steven A,
Stauss Harald M,
Liaboe Frederick O,
Kregel Kevin C
Publication year - 2013
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.27.1_supplement.lb763
Subject(s) - hsp70 , heat shock protein , hsp60 , heat stress , medicine , cellular stress response , hyperthermia , endocrinology , heat shock , downregulation and upregulation , homeostasis , chemistry , fight or flight response , biology , biochemistry , zoology , gene
Heat shock proteins (HSP) are upregulated as a key component of the cellular stress response to physiological challenges such as heat and exercise. In this experiment, we investigated the HSP response to the combined stressor of exercise plus hyperthermia in a chronic exertional heat stress (ExHS) model. In the ExHS experiments, male Sprague‐Dawley rats were run at 7–11 m/min in an environmental chamber (39°C) until core temperature (T c ) reached 41.8°C. Animals were exposed to 2 bouts of exertional heat stress per day for 5 consecutive days. In the passive heat stress experiment (HS), animals were placed in the chamber (45°C) until T c reached 41.8°C. Nonheated animals served as controls. Three days after the final bout of ExHS or HS, rats were euthanized, and livers and quadriceps were harvested. HSPs were evaluated on whole‐tissue homogenates by immunoblotting. In the quadriceps and liver, HSP70 was barely detectable in the nonheated condition; however it was elevated in both tissues in response to HS and ExHS. Interestingly, liver in the the ExHS group displayed a 77% greater expression of HSP70 and a 35% greater expression of HSP60 compared to the HS group. However, in the quadriceps expression of HSP60 and HSP70 did not differ between HS and ExHS. Compared to the quadriceps, this augmented response of the liver to exertional heat stress suggests greater perturbation to homeostasis in the liver after ExHS.