Hypoxic effects on sympathetic vasomotor outflow and blood pressure during exercise with inspiratory resistance

• DOI: 10.1152/ajpregu.00489.2012
• Publication Date: 2013-01-03T02:37:41Z
• Authors: Keisho Katayama; Shin Yamashita; Koji Ishida; Erika Iwamoto; Teruhiko Koike; Mitsuru Saito
• Keywords: Microneurography; Vasomotor

The purpose of the present study was to clarify influence inspiratory resistive breathing during exercise under hypoxic conditions on muscle sympathetic nerve activity (MSNA) and blood pressure (BP). Six healthy males completed this study. subjects performed a submaximal test using cycle ergometer in semirecumbent position normoxic [inspired oxygen fraction (FiO2) = 0.21] (FiO2 0.12-0.13) conditions. carried out two 10-min exercises at 40% peak uptake [spontaneous for 5 min voluntary with resistance (breathing frequency: 60 breaths/min, expiratory times were set 0.5 s each)]. MSNA recorded via microneurography right median elbow. A progressive increase burst frequency (BF) leg-cycling normoxia hypoxia accompanied by an augmentation BP. increased BF mean arterial BP (MBP) (MSNA BF, 55.7 ± 1.4 bursts/min, MBP, 134.3 6.6 mmHg) higher than those 39.2 1.8 123.6 4.5 mmHg). These results suggest that enhancement condition leads large increases vasomotor outflow dynamic leg exercise.