Luchtel D L, Martin A W, Deyrup-Olsen I
Cell Tissue Res. 1984;235(1):143-51. doi: 10.1007/BF00213734.
Studies were carried out to identify the route by which macromolecules and large volumes of fluid traverse the skin of terrestrial gastropods. Electron micrographs of the skin of the banana slug Ariolimax columbianus demonstrated that carbon particles can enter large, specialized cells and pass thence to the exterior. These cells, which are termed channel cells, range up to 500 micron in length; they reach from the external surface of the skin to deep within the subepithelial interstitium. At the light-microscope level they show a large central channel or reservoir apparently filled with homogeneous fluid; after injection of ink into the body cavity this central channel becomes ink-filled. Electron micrographs show cisternae of the smooth endoplasmic reticulum, opening from the cell surface and occasionally traversing the entire cytoplasmic layer. The neurohormone arginine vasotocin stimulates fluid and particle movement through the channel cell; this response is inhibited by norepinephrine. Fluid output is dependent on the presence of a transwall hydrostatic pressure gradient of about 7 torr or above, as well as on activation of the channel cells.
开展了多项研究以确定大分子和大量液体穿过陆生腹足动物皮肤的途径。对香蕉蛞蝓（Ariolimax columbianus）皮肤的电子显微镜照片显示，碳颗粒可以进入大型特化细胞，然后从那里通向外部。这些细胞被称为通道细胞，长度可达500微米；它们从皮肤的外表面延伸到上皮下间质的深处。在光学显微镜水平上，它们显示出一个大的中央通道或贮池，显然充满了均匀的液体；将墨水注入体腔后，这个中央通道就会充满墨水。电子显微镜照片显示，光滑内质网的池从细胞表面开口，偶尔贯穿整个细胞质层。神经激素精氨酸血管加压素刺激液体和颗粒通过通道细胞移动；这种反应被去甲肾上腺素抑制。液体输出取决于约7托或更高的跨壁静水压力梯度的存在，以及通道细胞的激活。
