Premium
Effects of Tempol on Endothelial‐Dependent Vasodilation in Soleus Muscle Arterioles in Response to Age and Exercise Training
Author(s) -
Sindler Amy Lynn,
Kang Lori,
Dominguez James,
Reyes Rafael,
MullerDelp Judy
Publication year - 2007
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.21.6.lb98-c
Subject(s) - sed , vasodilation , nitric oxide , vasoconstriction , medicine , endocrinology , soleus muscle , chemistry , bioavailability , pharmacology , skeletal muscle
Recent evidence suggests that age‐related declines in nitric oxide (NO)‐mediated dilation in soleus arterioles may be due to increased O 2 − production, which increases with age and may uncouple NOS to generate reactive oxygen species and decreased NO bioavailability. We previously demonstrated that age‐related declines in endothelial‐dependent dilation (EDD) in soleus arterioles are restored with exercise training potentially by increasing NO bioavailability. Thus, our goal was to examine the effect of an O 2 − scavenger (Tempol) on EDD in young (Y) and old (O) trained rats. Y (3 mo) and O (22 mo) male rats were exercise trained (ET) or sedentary (SED) for 10 wks. Soleus 1A arterioles were isolated, cannulated and pressurized at 70 cm H 2 0. EDD was assessed by exposure to ACh (1e −10 – 1e −4 M) or increasing intraluminal flow (5 – 60 nl/s) under control conditions and following 20 min incubation with Tempol (1mM). Age decreased NO‐mediated dilation; however, exercise training increased EDD in Y and restored EDD in O to that of Y SED rats. Tempol reduced ACh‐induced dilation in Y ET rats by 51% (p < .05) vs. a 31% decrease in Y SED. This reduction was greater in O ET rats with an 85% decrease in dilation (p < .05) vs. 44% in O SED. Tempol also reduced flow‐induced dilation in soleus arterioles in all groups. These data suggest Tempol inhibits EDD, promotes vasoconstriction and counteracts the enhanced EDD observed with exercise training.