Middle cerebral artery blood velocity and plasma catecholamines during exercise

• DOI: 10.1046/j.1365-201x.1996.564325000.x
• Publication Date: 2003-10-15T02:38:43Z
• Authors: F. POTT; K. JENSEN; H. HANSEN; N. J. CHRISTENSEN; N. A. LASSEN; N. H. SECHER
• Keywords: Cycling

During dynamic exercise, mean blood velocity ( V ) in the middle cerebral artery (MCA) demonstrates a graded increase to work rate and reflects regional flow. At high rate, however, vasoactive levels of plasma catecholamines could mediate vasoconstriction MCA thereby elevate at given volume To evaluate transcranial Doppler‐determined catecholamine levels, seven elite cyclists performed maximal performance test on bicycle ergometer. Results were compared with those elicited during five incremental exercise bouts rhythmic handgrip when are low. was elevated by 21±3% (mean±SE), which not statistically different from that established moderate cycling. However, highest submaximal intensities ergometer, increased 31±3% 48±4%, respectively, this significantly higher P <0.05). cycling, adrenaline 0.21±0.04 nmol L ‐1 rest 4.18±1.46 , noradrenaline 0.79±0.08 12.70±1.79 . These 12‐ 16‐fold than (adrenaline: 0.34±0.03 ; noradrenaline: 0.78±0.05 ). The intense ergometer cycling conforms some constriction catecholamines. Such an influence is unlikely low intensity