Interval sprint training for 10 weeks enhanced acetylcholine-induced dilation and eNOS content nonuniformly among arteries and arterioles that perfuse the white gastrocnemius muscle in rats.
Does interval sprint training improve endothelium-dependent dilation and eNOS content in arteries perfusing white gastrocnemius muscle in rats?
Interval sprint training induces non-uniform vascular adaptations, enhancing endothelium-dependent dilation and eNOS content in specific arteries perfusing the white gastrocnemius muscle.
The purpose of this study was to test the hypothesis that interval sprint training (IST) selectively increases endothelium-dependent dilation (EDD) and endothelial nitric oxide synthase and/or superoxide dismutase-1 protein content in arteries and/or arterioles that perfuse the white portion of rat gastrocnemius muscle (WG). Male Sprague-Dawley rats completed 10 wk of IST (n = 62) or remained sedentary (Sed) (n = 63). IST rats performed six 2.5-min exercise bouts, with 4.5 min of rest between bouts (60 m/min, 15% incline), 5 days/wk. EDD was assessed from acetylcholine (ACh)-induced increases in muscle blood flow measured in situ and by ACh-induced dilation of arteries and arterioles first to third order (1A-3A) that perfuse red gastrocnemius muscle (RG) and WG. Artery protein content was determined with immunoblot analysis. ACh-induced increases in blood flow were enhanced in WG of IST rats. eNOS content was increased in conduit arteries, gastrocnemius feed artery, and fourth-order arterioles from WG and fifth-order arterioles of RG but not in 2As from RG. EDD was examined in 2As and 3As from a subset of IST and Sed rats. Arterioles were canulated with micropipettes, and intraluminal pressure was set at 60 cmH2O. Results indicate that passive diameter (measured in 0 calcium PSS) of WG 2As was similar in IST and Sed, whereas diameter of WG 3As was greater in IST (96 +/- 8 microm) than Sed (73 +/- 4 microm). WG 2As and 3As of IST rats exhibited greater spontaneous tone, but sensitivity to stretch, phenylephrine, and sodium nitroprusside was similar to Sed arterioles. ACh-induced dilation was enhanced by IST in WG 2As but not in RG 2As or WG 3As. We conclude that IST induces vascular adaptations nonuniformly among arteries that perfuse WG muscle.
Laughlin et al. (Thu,) reported a other. Interval sprint training (IST) vs. Sedentary was evaluated on Endothelium-dependent dilation (EDD) and eNOS content in arteries/arterioles perfusing white gastrocnemius muscle. Interval sprint training for 10 weeks enhanced acetylcholine-induced dilation and eNOS content nonuniformly among arteries and arterioles that perfuse the white gastrocnemius muscle in rats.