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Glucose Reduces the Osmopressor Response in Connection with the Tyrosine Phosphorylation of Focal Adhesion Kinase in Red Blood Cells

摘要


Glucose ingestion attenuates the water ingestion-induced increase in the total peripheral vascular resistance and orthostatic tolerance. We investigated the gastrointestinal physiology of glucose by examining the effect of glucose ingestion on the functional expression of focal adhesion kinase (FAK) in red blood cell (RBC) membrane. This study was performed in 24 young, healthy subjects. Blood samples were collected at 5 min before and 25 min and 50 min after an ingestion of 10% glucose water 500 mL, water 500 mL, or normal saline 500 mL. We determined glucose and osmolality in plasma, and phosphorylation of aquaporin 1 (AQP1), glucose transporter 1 (Glut1), and FAK in RBC membrane. Our results showed that glucose ingestion reduced the rise of peripheral vascular resistance after water ingestion and upregulated the serine phosphorylation of Glut1. It also lowered both the serine phosphorylation of FAK and tyrosine phosphorylation of AQP1, compared with the ingestion of either water or saline. In an ex vivo experiment, glucose activated the Glut1 receptor and subsequently reduced the expression of FAK compared with 0.8% saline alone. We concluded that glucose activates Glut1 and subsequently lowers the functional expression of FAK, a cytoskeleton protein of RBCs. The functional change in the RBC membrane proteins in connection with the attenuation of osmopressor response may elucidate the pathophysiology of glucose in postprandial hypotension.

參考文獻


Schroeder C, Bush VE, Norcliffe LJ, Luft FC, Tank J, Jordan J, et al. Water drinking acutely improves orthostatic tolerance in healthy subjects. Circulation 2002;106:2806-11.
Scott EM, Greenwood JP, Stoker JB, Gilbey SG, Mary DA. Water drinking and sympathetic activation. Lancet 2000;356:2013.
Hirayama M, Watanabe H, Koike Y, Hasegawa Y, Kanaoke Y, Sakurai N, et al. Postprandial hypotension: Hemodynamic differences between multiple system atrophy and peripheral autonomic neuropathy. J Auton Nerv Syst 1993;43:1-6.
Lu CC, Li MH, Ho ST, Lu CL, Lin JC, Lin TC, et al. Glucose reduces the effect of water to promote orthostatic tolerance. Am J Hypertens 2008;21:1177-82.
Mathias CJ, da Costa DF, Fosbraey P, Bannister R, Wood SM, Bloom SR, et al. Cardiovascular, biochemical and hormonal changes during food-induced hypotension in chronic autonomic failure. J Neurol Sci 1989;94:255-69.

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