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Contribution of Kv1 channel activity to myogenic responses in skeletal muscle arterioles with aging and exercise training (678.7)
Author(s) -
Ghosh Payal,
Solis Fredy,
Dominguez Jimmy,
Delp Michael,
MullerDelp Judy
Publication year - 2014
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.28.1_supplement.678.7
Subject(s) - myogenic contraction , skeletal muscle , constriction , medicine , endocrinology , microcirculation , blockade , chemistry , smooth muscle , receptor
The impaired myogenic constriction of skeletal muscle arterioles observed with advancing age may be the result of increased Kv channel activity. Exercise training has been shown to restore myogenic responses. The purpose of this study was to determine the role of Kv1 channel activity in these adaptations in reactivity. Young and old male Fischer 344 rats were randomly assigned to either a sedentary (YSED and OSED) or exercise trained (YET and OET) group. Training consisted of treadmill running (15m/min, 15°incline, 1hr/d, 5d/wk for 10 wks). Soleus muscle first order arterioles were isolated and cannulated for in vitro study. Myogenic responsiveness was determined by exposing arterioles to incremental changes in intraluminal pressure from 0 to 140 cmH20, either in the presence or absence of Kv1 channel blocker correolide. Exercise enhanced myogenic tone in arterioles from both old and young rats and restored myogenic responsiveness in old rats to that of YSED rats. Kv1 channel blockade abolished the training effect in young rats, and resulted in greater constriction at lower pressures in YSED, but had no effect in YET rats. In both OSED and OET rats, Kv1 channel blockade led to increased myogenic constriction; however, the training effects persisted. These results suggest that Kv1 channel activity may play a role in modulating myogenic tone in young and old rats. Increased myogenic constriction after training in young rats may be mediated through a reduction in Kv1 channel activity. However, improved myogenic responsiveness with training in old rats appears to be mediated through a different pathway. Grant Funding Source : Supported by NIH R01HL090937