抄録
Mental task causes a pressor response with concomitant increase in vascular resistance (VR) in the superior mesenteric artery (SMA), whereas meal intake decreases VR in the SMA. To investigate whether this decrease in VR affects the pressor response to mental task, we compared cardiovascular responses to mental task in the fasting and post-prandial state. Ten healthy subjects (5 males and 5 females, 24 ± 1 yr, 56 ± 2 kg, mean ± SEM) performed color word test (CWT) for 5 min after 5 min of baseline measurement in the over night fasting state. On another day, the subjects ingested 300 kcal solid food within 5 min immediately before the CWT. Mean arterial pressure (MAP), blood velocity (BV) in the SMA, and blood flow (BF) in the finger skin and forearm were measured throughout the protocols. MAP was divided by BV in the SMA, and BF in the skin and forearm to yield an index of VR. The baseline variables did not differ significantly between the fasting and post-prandial state. In the fasting state, CWT significantly increased MAP (13 ± 3%), and VR in SMA (8 ± 3%), skin (129 ± 48%) and forearm (64 ± 25%) from the baseline (P < 0.05). In the post-prandial state, the CWT significantly increased MAP (14 ± 4%) despite the absence of a significant change in VR in SMA, and it significantly increased VR in the skin (178 ± 64%) and forearm (124 ± 45%). These findings suggest that VR in SMA decreased by meal intake does not affect the pressor response to CWT. (2006 Danone Institute of Japan Research Grant) [J Physiol Sci. 2007;57 Suppl:S199]
