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Hsp70 distribution patterns in rat skeletal muscle and vasculature post high and low intensity exercise
Author(s) -
Kowalchuk Hana,
Melling C.W. James,
Noble Earl
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.lb713
Subject(s) - hsp70 , skeletal muscle , intensity (physics) , blood flow , treadmill , heat shock protein , medicine , shock (circulatory) , chemistry , endocrinology , anatomy , biochemistry , gene , physics , quantum mechanics
Contracting skeletal muscle works as an integrated unit where increased muscle blood flow, myofiber (MF) activation and elevated temperature represent stresses which result in induction of the cytoprotective heat shock protein 70 (Hsp70) in blood vessels (BV) and MF. The effect of exercise intensity on Hsp70 expression within, and relationships between, these structures has yet to be examined. Tested hypotheses were 1) with increasing exercise intensity, more BVs, progressing from large to small would express Hsp70 2) MFs expressing Hsp70 would be located adjacent to Hsp70 expressing BVs. Male rats served as controls or were run for 1h on a treadmill (2% incline) at 15m/min (LoEx) or 30m/min (HiEx). 24 hr post‐exercise the white portion of the vastus muscle was harvested for localization of Hsp70 (n=10/group). The ratio of BVs expressing Hsp70/total vessels was greater in HiEx vs LoEx as a consequence of increased expression in small vessels (P<0.05). Hsp70 integrated density was also greater in large vs small BVs (P<0.05). Finally, the ratio of Hsp70 expressing MFs/total MFs was higher around smaller vs larger BVs (P<0.05). These observations demonstrate that HiEx produces a greater and more extensive Hsp70 response than LoEx in the vasculature, possibly as a result of vessel recruitment. The greater Hsp70 response in MF surrounding small BVs suggests an intensity‐dependent linkage of MF recruitment with blood flow.