Marshall A T, King P, Condron R J, Phillips J G
Cell Tissue Res. 1987 Jul;249(1):179-88. doi: 10.1007/BF00215432.
The duct system of the nasal salt gland of the duck comprises central central canals, secondary ducts and main ducts. The secondary and main ducts consist of a layer of columnar cells overlying a layer of small cuboidal cells. The columnar cells have complex intercellular spaces showing evidence of Na+K+-ATPase at the apical regions. Approximately 70% of surface area of the duct system is external to the gland. During adaptation to salt water the duct system increases in size as does the gland. Although the components of the gland of adapted ducks, including the duct system within the gland, increase in size compared with normal ducks, the percentage volume densities of the components remain similar in both categories of ducks, i.e. the duct system increases in size in proportion to the glandular tissue. The volume of the duct system external to the gland is six to seven times larger than the volume within the gland. Thus, if ductal modification of secreted fluid occurs, it will be most likely to take place in the ducts external to the gland. Total surface areas of the duct system were measured from serial sections of glands and ducts from one normal and one adapted duck. These were used to calculate possible flux rates of water and sodium across the duct epithelium, assuming the occurrence of either water reabsorption of sodium secretion. Although these flux rates are high it is shown that they are similar to calculated flux rates across the luminal surface of the secretory tubules.
鸭鼻盐腺的导管系统由中央管、二级导管和主导管组成。二级导管和主导管由一层柱状细胞覆盖在一层小立方体细胞之上构成。柱状细胞具有复杂的细胞间间隙，在顶端区域显示出钠钾ATP酶的迹象。导管系统约70%的表面积位于腺体外部。在适应盐水的过程中，导管系统和腺体一样会增大。虽然适应后的鸭子的腺体组成部分，包括腺体内的导管系统，与正常鸭子相比体积增大，但两类鸭子中各组成部分的体积密度百分比仍保持相似，即导管系统与腺组织成比例增大。腺体外部导管系统的体积比腺体内的体积大六到七倍。因此，如果分泌液的导管发生改变，最有可能发生在腺体外部的导管中。从一只正常鸭子和一只适应后的鸭子的腺体和导管的连续切片中测量了导管系统的总表面积。假设发生水重吸收或钠分泌，这些数据被用来计算水和钠穿过导管上皮的可能通量率。虽然这些通量率很高，但结果表明它们与计算出的穿过分泌小管腔表面的通量率相似。
