Introduction The study evaluated the role of lifelong physical activity for leg vascular function in postmenopausal women (61 ± 1 yr). Method The study design was cross-sectional with three different groups based on self-reported physical activity level with regard to intensity and volume over the past decade: inactive (n = 14), moderately active (n = 12), and very active (n = 15). Endothelial-dependent and smooth muscle-dependent leg vascular function were assessed by ultrasound Doppler measurements of the femoral artery during infusion of acetylcholine (Ach), the nitric oxide (NO) donor sodium nitroprusside and the prostacyclin analog epoprostenol. Thigh muscle biopsies, arterial and venous plasma samples were obtained for assessment of vasodilator systems. Results The very active group was found to have 76% greater responsiveness to Ach compared with the sedentary group accompanied by 200% higher prostacyclin synthesis during Ach infusion. Smooth muscle cell responsiveness to sodium nitroprusside and epoprostenol was not different between groups. The protein amount of endothelial NO synthase and endogenous antioxidant enzymes in muscle tissue was higher in the very active than the inactive group. The moderately active group had a similar endothelial and smooth muscle cell responsiveness as the inactive group. A secondary comparison with a smaller group (n = 5) of habitually active young (24 ± 2 yr) women indicated that smooth muscle cell responsiveness and endothelial responsiveness are affected by age per se. Conclusions This study shows that leg vascular function and the potential to form prostacyclin and NO in late postmenopausal women, is influenced by the extent of lifelong physical activity.
Purpose: This study aimed to evaluate the influence of lifelong regular physical activity on skeletal muscle capillarization in women. Methods: Postmenopausal women, 61±4 yr old, were divided according to self-reported physical activity level over the past 20 yrs: sedentary (SED; n = 14), moderately active (MOD; n = 12), and very active (VERY; n = 15). Leg blood flow (LBF) was determined by ultrasound Doppler, and blood samples were drawn from the femoral artery and vein for calculation of leg oxygen uptake (LVO 2 ) at rest and during one-legged knee extensor exercise. A skeletal muscle biopsy was obtained from the vastus lateralis and analyzed for capillarization and vascular endothelial growth factor (VEGF) and mitochondrial OXPHOS proteins. Platelets were isolated from venous blood and analyzed for VEGF content and effect on endothelial cell proliferation. Results: The exercise-induced rise in LBF and LVO 2 was faster (P = 0.008) in VERY compared with SED and MOD. Steady-state LBF and LVO 2 were lower (P < 0.04) in MOD and VERY compared with SED. Capillary-fiber ratio and capillary density were greater (P < 0.03) in VERY (1.65 ± 0.48 and 409.3 ± 57.5) compared with MOD (1.30 ± 0.19 and 365.0 ± 40.2) and SED (1.30 ± 0.30 and 356.2 ± 66.3). Skeletal muscle VEGF and OXPHOS complexes I, II, and V were ~1.6-fold and ~1.25-fold (P < 0.01) higher, respectively, in VERY compared with SED. Platelets from all groups induced an approximately nine-fold (P < 0.001) increase in endothelial cell proliferation. Conclusion: A very active lifestyle is associated with superior skeletal muscle exercise hemodynamics and greater potential for oxygen extraction concurrent with a higher skeletal muscle capillarization and mitochondrial capacity.
The menopausal transition is associated with increased prevalence of hypertension, and in time postmenopausal women (PMW) will exhibit a cardiovascular disease risk-score similar to male counterparts. Hypertension is associated with vascular dysfunction, but whether hypertensive PMW have blunted nitric-oxide (NO)-mediated leg vasodilator responsiveness, and whether this is reversible by high-intensity training (HIT) is unknown. To address these questions, we examined the leg vascular conductance (LVC) in response to femoral-infusion of acetylcholine (ACh) and sodium nitroprusside (SNP), and skeletal muscle markers of oxidative stress and NO bioavailability before and after HIT in PMW (12.9±6.0 (mean±SD) years since last menstrual cycle). We hypothesized that ACh- and SNP-induced LVC responsiveness was reduced in hypertensive compared to normotensive PMW and that 10 weeks of HIT would reverse the blunted LVC response and decrease blood pressure (BP).Nine hypertensive (HYP; clinical systolic/diastolic BP 149±11/91±83 mmHg) and 8 normotensive (NORM; 122±13/75±8 mmHg) PMW completed 10 weeks of bi-weekly small-sided floorball training (4-5x3-5 min interspersed by 1-3 min rest periods). Before training, the SNP-induced change in LVC was lower (P<0.05) in HYP compared with NORM. With training, the ACh- and SNP-induced change in LVC at maximal infusion rates i.e. 100 and 6 μg∙min-1∙kg leg mass-1, respectively, improved (P<0.05) in HYP only. Further, training decreased (P<0.05) clinical systolic/diastolic BP (-15±11/-9±7 mmHg) in HYP, and systolic BP (-10±9 mmHg) in NORM. Thus, the SNP-mediated LVC responsiveness was blunted in hypertensive PMW, and reversed by a period of HIT that was associated with a marked decrease in clinical BP.
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