Barber A, Deán J I, Jordana R, Ponz F
Departamento de Fisiología Animal, Facultad de Ciencias, Universidad de Navarra, Pamplona, Spain.
Rev Esp Fisiol. 1989;45 Suppl:215-23.
The intestine of Helix aspersa snail is able to actively transport sugars and amino acids. D-glucose, D-galactose and 3-oxymethylglucose share the same transport system with competitive inhibition between them, which is strictly Na(+)-dependent. Phlorizin has high affinity for that system and inhibits it competitively. D-fructose and L-arabinose are not actively transported, do not inhibit the transport of other sugars, and enter the tissue at a lineal rate with their concentration, which coincides with that of mannitol and with that of actively transportable sugars in the presence of 10(-4)M phlorizin. Galactose seems to enter the tissue from the serosal side through another carrier, with different specificity, Na(+)-independent, inhibited by phloretin but not by phlorizin. There are also transport systems for neutral amino acids, for the basic ones and for imino acids. Neutral amino acids present affinity for the other systems, whereas the basic ones and the imino acids seem to use only those proper to them. The system for imino acids is strictly Na(+)-dependent, but neutral amino acids and the basic ones continue to be transported and accumulated, although to a lesser extent, in the absence of Na+. Transport of sugars and amino acids is scarcely O2 dependent, although it is inhibited by 10(-4)M DNP. It is also partially inhibited by harmaline and by ouabain.
庭院蜗牛的肠道能够主动转运糖类和氨基酸。D-葡萄糖、D-半乳糖和3-氧甲基葡萄糖共用同一转运系统，它们之间存在竞争性抑制，且该转运系统严格依赖Na⁺。根皮苷对该系统具有高亲和力并能竞争性抑制它。D-果糖和L-阿拉伯糖不被主动转运，不抑制其他糖类的转运，且以与浓度呈线性关系的速率进入组织，这与甘露醇以及在存在10⁻⁴M根皮苷时可被主动转运的糖类的情况一致。半乳糖似乎通过另一种载体从浆膜侧进入组织，具有不同的特异性，不依赖Na⁺，受根皮素抑制但不受根皮苷抑制。还存在中性氨基酸、碱性氨基酸和亚氨基酸的转运系统。中性氨基酸对其他系统有亲和力，而碱性氨基酸和亚氨基酸似乎仅使用它们各自特有的转运系统。亚氨基酸的转运系统严格依赖Na⁺，但在没有Na⁺的情况下，中性氨基酸和碱性氨基酸仍能继续被转运和积累，尽管程度较小。糖类和氨基酸的转运几乎不依赖O₂，尽管它会被10⁻⁴M的二硝基苯酚抑制。它也会被哈尔满和哇巴因部分抑制。
