Elizabeth M Gittemeier1, Tyler Ericson2, Payal Ghosh3, Steven W Copp1, Alexander B Opoku-Acheampong1, Bradley J Behnke4,5. 1. Department of Kinesiology, Kansas State University, Manhattan, KS, USA. 2. Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA. 3. Department of Food, Nutrition and Exercise Sciences, Florida State University, Tallahassee, FL, USA. 4. Department of Kinesiology, Kansas State University, Manhattan, KS, USA. bjbehnke@ksu.edu. 5. Department of Kinesiology, Johnson Cancer Research Center, Kansas State University, Manhattan, KS, 66506, USA. bjbehnke@ksu.edu.
Abstract
It is unknown whether aging or exercise training affect the dynamics of arteriolar vasoconstriction. PURPOSE: We hypothesized that old age will slow, and exercise training will speed, the dynamics of skeletal muscle arteriolar vasoconstriction in resistance vessels of aged rats. METHOD: Young (6 month old) and aged (24 month old) male Fischer-344 rats were assigned to sedentary (Sed: n = 6/age group) or exercise-trained (ET: n = 5 aged and 6 young; via treadmill running for 10-12 weeks) groups. After completion of training, arterioles from the red portion of the gastrocnemius muscle were removed, cannulated, and exposed to 10-4 M norepinephrine (NE) or 20 mM caffeine. Changes in luminal diameter were recorded for analysis of constrictor dynamics. RESULT: Old age blunted all kinetic parameters (i.e., time delay, time constant) resulting in vasoconstriction taking ~3 times as long to reach a steady state (SS) versus younger counterparts for NE (aged-sed: 15.6 ± 6.0 versus young-sed: 4.6 ± 0.5 s; P < 0.05) with a similar time course to caffeine. Exercise training resulted in a similar time to SS between age groups for NE (aged-ET: 6.8 ± 1.6 versus young-ET: 7.0 ± 0.6 s) and caffeine (aged-ET: 7.8 ± 0.6 versus young-ET: 8.6 ± 1.0 s). CONCLUSION: The results of this study demonstrate that aging blunts the rate of vasoconstriction in skeletal muscle resistance vessels to the sympathetic neurotransmitter NE due, in part, to an attenuated rate of contraction from intracellular calcium release. Further, exercise training speeds the dynamics of constriction to both NE and caffeine with old age.
It is unknown whether aging or exercise training affect the dynamics of arteriolar vasoconstriction. PURPOSE: We hypothesized that old age will slow, and exercise training will speed, the dynamics of skeletal muscle arteriolar vasoconstriction in resistance vessels of aged rats. METHOD: Young (6 month old) and aged (24 month old) male Fischer-344 rats were assigned to sedentary (Sed: n = 6/age group) or exercise-trained (ET: n = 5 aged and 6 young; via treadmill running for 10-12 weeks) groups. After completion of training, arterioles from the red portion of the gastrocnemius muscle were removed, cannulated, and exposed to 10-4 M norepinephrine (NE) or 20 mM caffeine. Changes in luminal diameter were recorded for analysis of constrictor dynamics. RESULT: Old age blunted all kinetic parameters (i.e., time delay, time constant) resulting in vasoconstriction taking ~3 times as long to reach a steady state (SS) versus younger counterparts for NE (aged-sed: 15.6 ± 6.0 versus young-sed: 4.6 ± 0.5 s; P < 0.05) with a similar time course to caffeine. Exercise training resulted in a similar time to SS between age groups for NE (aged-ET: 6.8 ± 1.6 versus young-ET: 7.0 ± 0.6 s) and caffeine (aged-ET: 7.8 ± 0.6 versus young-ET: 8.6 ± 1.0 s). CONCLUSION: The results of this study demonstrate that aging blunts the rate of vasoconstriction in skeletal muscle resistance vessels to the sympathetic neurotransmitter NE due, in part, to an attenuated rate of contraction from intracellular calcium release. Further, exercise training speeds the dynamics of constriction to both NE and caffeine with old age.
Authors: M Harold Laughlin; Michael J Davis; Niels H Secher; Johannes J van Lieshout; Arturo A Arce-Esquivel; Grant H Simmons; Shawn B Bender; Jaume Padilla; Robert J Bache; Daphne Merkus; Dirk J Duncker Journal: Compr Physiol Date: 2012-01 Impact factor: 9.090
Authors: Cristiane del Corsso; Olga Ostrovskaya; Claire E McAllister; Keith Murray; William J Hatton; Alison M Gurney; Nicholas J Spencer; Sean M Wilson Journal: Mech Ageing Dev Date: 2006-01-18 Impact factor: 5.432
Authors: Payal Ghosh; Fredy R Mora Solis; James M Dominguez; Scott A Spier; Anthony J Donato; Michael D Delp; Judy M Muller-Delp Journal: J Appl Physiol (1985) Date: 2015-01-29
Authors: Judy Muller-Delp; Scott A Spier; Michael W Ramsey; Lisa A Lesniewski; Anthony Papadopoulos; J D Humphrey; Michael D Delp Journal: Am J Physiol Heart Circ Physiol Date: 2002-05 Impact factor: 4.733
Authors: Soung Hun Park; Oh Sung Kwon; Song-Young Park; Joshua C Weavil; Robert H I Andtbacka; John R Hyngstrom; Van Reese; Russell S Richardson Journal: Am J Physiol Heart Circ Physiol Date: 2018-09-07 Impact factor: 4.733
Authors: John W Seawright; Harini Sreenivasappa; Holly C Gibbs; Samuel Padgham; Song Y Shin; Christine Chaponnier; Alvin T Yeh; Jerome P Trzeciakowski; Christopher R Woodman; Andreea Trache Journal: Front Physiol Date: 2018-07-31 Impact factor: 4.566