Purpose:To study the saturation characteristics of the glucose transport across the bovine retinal pigment epithelium(RPE).Methods:The bovine RPE preparations were munted with a modified Ussing chamber.The L-[^(3)H]-g...Purpose:To study the saturation characteristics of the glucose transport across the bovine retinal pigment epithelium(RPE).Methods:The bovine RPE preparations were munted with a modified Ussing chamber.The L-[^(3)H]-glucose and 3-0-methyl-D-[^(14)C]-glucose fluxes across the RPE from the choroid to retina were studied at different glucose concentrations.Results:The glucose transport was found to be stereospecific,with 3-0-methyl-D-glucose(MDG)being transported about three times faster than L-glucose.The glucose transport showed typical saturation characteristics in Michaelis-Menten fashion.The V_(max)and the K_(m)of corrected MDG were 2452 nmol cm^(-2)h^(-1)and 30.8 mM respectively.It was shown that the glucose transport system was saturated at 61.6 mM.Conclusions:The saturation characteristics of the corrected MDG flux suggested that the capacity of glucose transport through the bovine RPE is immense.展开更多
基金Correspondence address:Chi Ho T0,PhD Assistant Professor,Departnent of Optometry and Radiography.The Hong Kong Poly-lechric University,Hung Hom,Kowloon,Hong Kong.Telephone:(0852)27666102,Fax mumber(0852)27646051,Email:ORCHTO@P0LYU.EDU.HK
文摘Purpose:To study the saturation characteristics of the glucose transport across the bovine retinal pigment epithelium(RPE).Methods:The bovine RPE preparations were munted with a modified Ussing chamber.The L-[^(3)H]-glucose and 3-0-methyl-D-[^(14)C]-glucose fluxes across the RPE from the choroid to retina were studied at different glucose concentrations.Results:The glucose transport was found to be stereospecific,with 3-0-methyl-D-glucose(MDG)being transported about three times faster than L-glucose.The glucose transport showed typical saturation characteristics in Michaelis-Menten fashion.The V_(max)and the K_(m)of corrected MDG were 2452 nmol cm^(-2)h^(-1)and 30.8 mM respectively.It was shown that the glucose transport system was saturated at 61.6 mM.Conclusions:The saturation characteristics of the corrected MDG flux suggested that the capacity of glucose transport through the bovine RPE is immense.
