Blood flow to the active muscles and arterial blood pressure (ABP) increases during dynamic exercise, whereas blood flow to inactive organs (e.g., splanchnic organs and inactive limbs) declines. Aging leads to exaggerated ABP responses to exercise in females, but whether this is related to greater splanchnic vasoconstriction is unknown. This study sought to clarify the effect of aging in females on celiac artery blood flow during dynamic light-intensity exercise. Twelve healthy young females (YF: 20±2yrs, mean±SD) and 12 healthy older females (OF: 71±4yrs) performed dynamic knee-extension and -flexion exercise at 30% of heart rate reserve for 4-min. The absolute changes from baseline (Δ) for mean arterial blood pressure (MAP), celiac artery mean blood flow (celMBF), and celiac vascular conductance (celVC) during exercise were calculated. ABP was measured using an automated sphygmomanometer, and celMBF was recorded by Doppler ultrasonography. The increase in MAP during exercise was greater in OF than in YF (YF: +14±7mmHg, OF: +24±13mmHg, P=0.028). The celMBF decreased during exercise in both groups, but there was no significant difference in the response between YF and OF (YF: -93.0±66.1mL/min, OF: -89.6±64.0mL/min, P=0.951). The celVC also decreased during exercise and remained lower than baseline during exercise. However, the response was not different between YF and OF (YF: -1.8±1.0mL/min/mmHg, OF: -1.5±0.6mL/min/mmHg, P=0.517). These results demonstrate that aging in females has minimal influence on splanchnic artery hemodynamic responses during dynamic light-intensity exercise, suggesting that exaggerated ABP responses during exercise in OF are not due to greater splanchnic vasoconstriction.
Keywords: aging; blood flow distribution; celiac artery; dynamic exercise; splanchnic blood flow.