Differential arterial blood flow response of splanchnic and renal organs during low-intensity cycling exercise in women

Abstract

To investigate the regional hemodynamic responses of abdominal arteries at the onset of exercise and to focus on their transient responses, eight female subjects (21-30 yr) performed ergometer cycling exercise at 40 W for 4 min in a semi-supine position. Mean blood velocities (MBVs) in the right renal (RA), superior mesenteric (SMA), and splenic (SA) arteries were measured by pulsed echo-Doppler ultrasonography, with beat-by-beat measurements of heart rate (HR) and mean arterial pressure (MAP). The vascular resistance index (RI) of each artery was calculated from MBV/MAP. MAP (76 +/- 9 to 83 +/- 8 mmHg at 4 min) and HR (60 +/- 7 to 101 +/- 9 beats/min at 4 min) increased during exercise (P < 0.05). The MBV of RA and SA rapidly decreased after the onset of exercise (30 s; -19 +/- 5% and -19 +/- 12%, respectively), reaching -27 +/- 7% and -27 +/- 15% at the end of exercise (P < 0.05). RI did not change during the initial 30 s of exercise, reflecting a reduction in MAP, and increased toward the end of the exercise (+55 +/- 21% and +59 +/- 39%, respectively). In contrast, both the MBV and RI in the SMA remained constant throughout the exercise. The results indicate that, whereas the responses of renal and splenic vessels changed similarly throughout the protocol, the vascular response of SMA that mainly supplies blood to the intestinal tract was unchanged during exercise. We, therefore, conclude that low-intensity cycling exercise resulted in differential blood flow responses in arteries supplying the abdominal organs.

Temporal assessment of pancreatic blood flow and perfusion following secretin stimulation using noninvasive MRI

“…Baseline vessel measurements obtained here were in agreement with those reported in the literature for flow 20,27,28 and velocity, 20,27,29 and the CV for SMA, HA, and SA are consistent with those reported for the renal artery. 30 Dambreville et al 30 also…”

Blood flow in non-muscle tissues and organs during exercise: Nature of splanchnic and ocular circulation

“…One study found that the blood flow decreased by 30% in the SMA, whereas it decreased by 50% in the CA during dynamic exercise at 75% V ・ O2max 12) . In another study, the blood flow decreased by 30% in the spleen, but not in the SMA, during light-intensity exercise 4) . It appears reasonable to assume that non-uniform responses in the splanchnic blood flow are controlled multifactorially by the autonomic, humoral, and local organ-specific regulatory systems.…”

“…Renal flow decreases proportionally with increasing exercise intensity via vasoconstriction [1][2][3] , while cardiac output increases up to fivefold of the resting value in exercising humans 3) . Even light-intensity exercise decreased renal flow by 20% within 30 s of exercise onset 4) . In addition, during exercise the blood flow increases in organs other than exercising muscles.…”

Acute effect of oral water intake during exercise on post-exercise hypotension

“…The details were described in our previous study. 18 The vascular conductance (VC) of the brachial artery was calculated as the ratio of each blood flow to MAP.…”