Analytical, Diagnostic and Therapeutic Techniques and Equipment Commons^™

Sources Of Intravascular Atp During Exercise In Humans: Critical Role For Skeletal Muscle Perfusion, Brett S. Kirby, Anne R. Crecelius, Jennifer C. Richards, Frank A. Dinenno

Health and Sport Science Faculty Publications

Exercise hyperemia is regulated by several factors and one factor known to increase with exercise that evokes powerful vasomotor action is extracellular ATP. The origination of ATP detectable in plasma from exercising muscle of humans is, however, a matter of debate and ATP has been suggested to arise from sympathetic nerves, blood sources (e.g. erythrocytes), endothelial cells, and skeletal myocytes, among others. Therefore, we tested the hypothesis that acute augmentation of sympathetic nervous system activity (SNA) results in elevated plasma ATP draining skeletal muscle, and that SNA superimposition during exercise further increases ATP vs exercise alone. We show that increased …

Impaired Skeletal Muscle Blood Flow Control With Advancing Age In Humans: Attenuated Atp Release And Local Vasodilation During Erythrocyte Deoxygenation, Brett S. Kirby, Anne R. Crecelius, Wyatt F. Voyles, Frank A. Dinenno

Health and Sport Science Faculty Publications

Rationale: Skeletal muscle blood flow is coupled with the oxygenation state of hemoglobin in young adults, whereby the erythrocyte functions as an oxygen sensor and releases ATP during deoxygenation to evoke vasodilation. Whether this function is impaired in humans of advanced age is unknown.

Objective: To test the hypothesis that older adults demonstrate impaired muscle blood flow and lower intravascular ATP during conditions of erythrocyte deoxygenation.

Methods and Results: We showed impaired forearm blood flow responses during 2 conditions of erythrocyte deoxygenation (systemic hypoxia and graded handgrip exercise) with age, which was caused by reduced local vasodilation. In young adults, …

Muscle Contraction Duration And Fibre Recruitment Influence Blood Flow And Vo2 Independent Of Contractile Work During Steady-State Exercise In Humans, Jennifer C. Richards, Anne R. Crecelius, Brett S. Kirby, Dennis G. Larson, Frank A. Dinenno

Health and Sport Science Faculty Publications

We tested the hypothesis that, among conditions of matched contractile work, shorter contraction durations and greater muscle fibre recruitment result in augmented skeletal muscle blood flow and oxygen consumption (O2) during steady-state exercise in humans. To do so, we measured forearm blood flow (FBF; Doppler ultrasound) during 4 minutes of rhythmic handgrip exercise in 24 healthy young adults and calculated forearm O2 via blood samples obtained from a catheter placed in retrograde fashion into a deep vein draining the forearm muscle. In Protocol 1 (n = 11), subjects performed rhythmic isometric handgrip exercise at mild and moderate intensities under conditions …

Disaggregating The Relative Influence Of Genetic, Environmental And Individual Factors On Ldl And Hdl Cholesterols And Bmi For A Sample Of African American (Aa) Mothers And Daughters, C. Jayne Brahler, Jewel Harden, Michelle Mchone, Matthew Soules, Eric Evans, Ann Alyanak, Fred Diakpieng, Paul M. Vanderburgh

Health and Sport Science Faculty Publications

There are many reports about the associations between blood lipids, body mass index (BMI) and dietary cholesterol intakes both within the individual and between related individuals. The purpose of this descriptive research project was to investigate the relationships between LDL and HDL cholesterols, body mass index and dietary cholesterol intakes for a sample of African American (AA) mothers and their daughters and to attempt to separate the contribution of genetic versus environmental factors. Mother and daughter participants (n =42 and 66, respectively) were 12-14-hours fasted when blood samples were drawn, heights and weights measured, and 24 hour food recalls completed.

Qtc Is Associated With Obesity And Physical Activity Level For African American Females, C. Jayne Brahler

Health and Sport Science Faculty Publications

Long QT syndrome (LQTS) is an independent risk factor for cardiovascular or ischemic disease mortality. Obesity as a cause for acquired LQTS in otherwise healthy individuals is rapidly gaining the attention of the scientific community. African American people have a higher incidence of obesity compared to Caucasians, yet race-specific information is not available for their prevalence of LQTS. Chronic physical activity can help reduce the incidence of obesity, yet little is known about the effects of chronic physical activity on acquired LQTS. Subjects in this study were a volunteer sample of African American mothers (21-53 yr, n = 44) and …