Fig. 5. Relationships of glucose filtration, excretion and reabsorption rates to plasma glucose concentration in the rainbow trout, allowing estimation of the in vivo glucose transport maximum from the plateau in glucose reabsorption. Points are for fish infused with glucose only and represent individual fish at different times, not mean values. See text for details. The equation of the regression line for glucose filtered is y=5.547x–2.224 (r²=0.9615, P<0.05), where y is the glucose filtration rate (µmol kg^–1 h^–1) and x is the plasma glucose concentration (mmol l^–1). The equation of the regression line for glucose excreted is y=0.942+log(1.207) x1.207^x (r²=0.9321, P<0.01), where y is the glucose excretion rate (µmol kg^–1 h^–1) and x is the plasma glucose concentration (mmol l^–1). The equation of the regression line for glucose reabsorbed is y=–96.182+246.349e^{–0.5{[(x–33.715)/23.302]2}} (r²=0.9149, P<0.05), where y is the glucose reabsorption rate (µmol kg^–1 h^–1) and x is the plasma glucose concentration (mmol l^–1).