title: Changes in regional cerebral blood flow distribution during postexercise hypotension in humans.
abstract: This investigation compared patterns of regional cerebral blood flow (rCBF) during exercise recovery both with and without postexercise hypotension (PEH). Eight subjects were studied on 3 days with randomly assigned conditions: 1) after 30 min of rest; 2) after 30 min of moderate exercise (M-Ex) at 60-70% heart rate (HR) reserve during PEH; and 3) after 30 min of light exercise (L-Ex) at 20% HR reserve with no PEH. Data were collected for HR, mean blood pressure (MBP), and ratings of perceived exertion and relaxation, and rCBF was assessed by use of single-photon-emission computed tomography. With the use of ANOVA across conditions, there were differences (P < 0.05; mean +/- SD) from rest during exercise recovery from M-Ex (HR = +12 +/- 3 beats/min; MBP = -9 +/- 2 mmHg), but not from L-Ex (HR = +2 +/- 2 beats/min; MBP = -2 +/- 2 mmHg). After M-Ex, there were decreases (P < 0.05) for the anterior cingulate (-6.7 +/- 2%), right and left inferior thalamus (-10 +/- 3%), right inferior insula (-13 +/- 3%), and left inferior anterior insula (-8 +/- 3%), not observed after L-Ex. There were rCBF decreases for leg sensorimotor regions after both M-Ex (-15 +/- 4%) and L-Ex (-12 +/- 3%) and for the left superior anterior insula (-7 +/- 3% and -6 +/- 3%), respectively. Data show that there are rCBF reductions within specific regions of the insular cortex and anterior cingulate cortex coupled with a postexercise hypotensive response after M-Ex. Findings suggest that these cerebral cortical regions, previously implicated in cardiovascular regulation during exercise, may also be involved in PEH.
authors.affiliation: Department of Physical Therapy, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas 75235-8876, USA. jon.williamson@utsouthwestern.edu
authors.forename: J W
authors.initials: JW
authors.lastname: Williamson
authors.forename: R
authors.initials: R
authors.lastname: McColl
authors.forename: D
authors.initials: D
authors.lastname: Mathews
mesh_terms: D000328:Adult; D001794:Blood Pressure / Q000502:physiology; D002540:Cerebral Cortex / Q000098:blood supply* / Q000000981:diagnostic imaging / Q000502:physiology; D002560:Cerebrovascular Circulation / Q000502:physiology*; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D007022:Hypotension / Q000000981:diagnostic imaging / Q000503:physiopathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D015899:Tomography, Emission-Computed, Single-Photon