Figure 4.

Decreases in forearm vascular conductance and muscle oxygenation (HbO₂ + MbO₂) elicited by reflex sympathetic activation by using LBNP. (a) The same level of LBNP produced a slightly greater vasoconstrictor response in the DMD patients than in controls. Controls, n = 8; DMD, n = 5. (b and c) In resting forearm, LBNP at −25 mmHg in the controls (b) produced decreases in muscle oxygenation comparable to LBNP at −20 mmHg in the DMD patients (c). In contracting forearm, the LBNP-induced decreases in muscle oxygenation were greatly attenuated in the controls, but not in the DMD patients. Controls, n = 7; DMD, n = 8; *, P < 0.05, LBNP at rest vs. handgrip.