Age- and fitness-related alterations in vascular sympathetic control

التفاصيل البيبلوغرافية
العنوان: Age- and fitness-related alterations in vascular sympathetic control
المؤلفون: Péter Studinger, Richard Goldstein, J. Andrew Taylor
المصدر: The Journal of Physiology. 587:2049-2057
بيانات النشر: Wiley, 2009.
سنة النشر: 2009
مصطلحات موضوعية: medicine.medical_specialty, Physiology, business.industry, Physical activity.status, Sympathetic nerve activity, Baroreflex, Pressure rise, Blood pressure, Endocrinology, Internal medicine, cardiovascular system, Neural control, Medicine, Sodium nitroprusside, business, Phenylephrine, circulatory and respiratory physiology, medicine.drug
الوصف: In the current study we explored (1) if there were differences in sympathetic activity and baroreflex function by age, sex, or physical activity status, (2) if any aspect of baroreflex function related to differences in resting sympathetic activity, and (3) if mechanical and/or neural baroreflex components related to differences in integrated baroreflex gain. Electrocardiogram, blood pressure, carotid diameter and muscle sympathetic nerve activity were recorded continuously at rest and during sequential bolus injections of sodium nitroprusside and phenylephrine in 22 young, 21 older sedentary and 10 older trained individuals. Analyses of co-variance were used to examine age, sex and training status differences and to explore the explanatory power of integrated baroreflex gain and its mechanical and neural components. Training status and sex influenced neither resting sympathetic outflow nor sympathetic baroreflex gain components. Older subjects had a smaller mechanical component and a strong tendency towards a greater neural component of the sympathetic baroreflex during both pressure falls and pressure rises. Opposing age-related changes in mechanical and neural components resulted in a smaller integrated gain during pressure falls, but a greater integrated gain during pressure rises in older subjects. Thus, in older individuals, compromised sympathetic activation to pressure falls was owing to the stiffening of barosensory vessels, whereas the more sensitive sympathoinhibition to pressure rise was due to an increased neural control. Enhanced neural control with age, however, did not contribute the increased resting sympathetic outflow, which indicates that these two changes are probably driven by distinct neural mechanisms.
تدمد: 0022-3751
DOI: 10.1113/jphysiol.2009.170134
URL الوصول: https://explore.openaire.eu/search/publication?articleId=doi_________::c4a72e579882836830bf136fc99947fc
https://doi.org/10.1113/jphysiol.2009.170134
Rights: OPEN
رقم الانضمام: edsair.doi...........c4a72e579882836830bf136fc99947fc
قاعدة البيانات: OpenAIRE
الوصف
تدمد:00223751
DOI:10.1113/jphysiol.2009.170134