DiMattio J, Zadunaisky J A
J Exp Zool. 1982 Feb 1;219(2):197-203. doi: 10.1002/jez.1402190209.
Evidence is presented demonstrating that in the dogfish, Squalus acanthias, D-glucose is transported from the blood to the ocular fluid compartments by a mechanism that is consistent with carrier-facilitated transport. Across the dogfish aqueous barrier D-glucose is transported 8.4 times faster than L-glucose, whereas this D/L transport ratio is only 5.5 in the rat. Similarly, the D/L transport ratio is 12.7 across the dogfish vitreous barrier and only 6.1 across this barrier in the rat. It is estimated that per unit area of vitreous barrier, the rat transports D-glucose faster than the dogfish but also has a greater passive permeability, as measured by L-glucose, and transport is therefore less efficient. Urea transport was found to be faster than L-glucose transport, suggesting a transport mechanism for urea other than simple diffusion. The sectional analysis of frozen vitreous humor indicated that the lens of the dogfish is supplied with D-glucose from both the ciliary epithelium and across the retinal pigment epithelium, while the retina receives D-glucose primarily across the pigment epithelium.
有证据表明，在角鲨（Squalus acanthias）中，D-葡萄糖通过一种与载体介导的转运相一致的机制从血液转运至眼内液腔室。在角鲨的水液屏障中，D-葡萄糖的转运速度比L-葡萄糖快8.4倍，而在大鼠中该D/L转运比仅为5.5。同样，在角鲨的玻璃体屏障中D/L转运比为12.7，而在大鼠中该屏障的D/L转运比仅为6.1。据估计，每单位面积的玻璃体屏障，大鼠转运D-葡萄糖的速度比角鲨快，但以L-葡萄糖测量时其被动通透性也更高，因此转运效率较低。发现尿素的转运速度比L-葡萄糖的转运速度快，这表明尿素的转运机制并非简单扩散。对冷冻玻璃体的切片分析表明，角鲨的晶状体从睫状体上皮和通过视网膜色素上皮都获得D-葡萄糖，而视网膜主要通过色素上皮接收D-葡萄糖。
