Plopper C G, Mariassy A T, Wilson D W, Alley J L, Nishio S J, Nettesheim P
Exp Lung Res. 1983 Dec;5(4):281-94. doi: 10.3109/01902148309061521.
Three types of nonciliated epithelial cells in mammalian conducting respiratory airways are thought to be secretory: mucous (goblet) cells, serous epithelial cells, and Clara cells. Mucous and serous cells are considered to be the secretory cells of the trachea. Clara cells are considered to be the secretory cells of the most distal conducting airways or bronchioles. To ascertain if mucous and serous epithelial cells are common to the tracheal epithelium of mammalian species, we characterized the ultrastructure and population densities of tracheal epithelial cells in six species: hamster (H), rat (Rt), rabbit (Rb), cat (C), Bonnet monkey (M. radiata) (B), and sheep (S). Following fixation by airway infusion with glutaraldehyde/paraformaldehyde, tracheal tissue was processed for light and electron microscopy (EM) by a selective embedding technique. Tracheal epithelium over cartilage was quantitated by light microscopy and characterized by transmission EM. Mucous cells were defined by abundant large nonhomogeneous granules, numerous Golgi complexes, basally located nuclei and granular endoplasmic reticulum (GER). The percentage of mucous cells in the tracheal epithelium was: H (0%), Rt (0.5%), Rb (1.3%), C (20.2%), B (8%), S (5.1%). Serous cells had homogeneous, electron-dense granules and extensive GER. Serous cells were present only in rats (39.2%). Clara cells had homogeneous electron-dense granules, abundant agranular endoplasmic reticulum (AER) and basal GER. Clara cells were found in hamsters (41.4%) and rabbits (17.6%). In sheep trachea, 35.9% of the epithelial cells had small electron-lucent granules, abundant AER and numerous Golgi complexes. In Bonnet monkey trachea, 16% of the epithelial cells had small electron-lucent granules, numerous polyribosomes, perinuclear Golgi apparatus and moderate GER. In cat trachea, 5.4% of the epithelial cells lacked granules, and had moderate numbers of mitochondria, moderate amounts of polyribosomes, a central nucleus, and long luminal microvilli. The percentage of the tracheal epithelial population occupied by basal, ciliated and nonciliated cells was: H (5.6%, 47.5%, 46.7%), Rt (13.4%, 40.6%, 45.9%), Rb (28.2%, 43.0%, 28.3%), C (37.3%, 36.1%, 26.7%), B (31%, 41%, 28%), S (28.5%, 30.6%, 41%). We conclude: 1) mucous and serous cells are not common to the tracheal epithelial lining of all mammalian species; 2) there is significant interspecies heterogeneity in the abundance, distribution and ultrastructure of tracheal secretory cells; 3) potential differences in the roles of nonciliated cells in tracheal function exists within tracheal epithelial populations and between species.
黏液（杯状）细胞、浆液性上皮细胞和克拉拉细胞。黏液细胞和浆液性细胞被视为气管的分泌细胞。克拉拉细胞被视为最远端传导气道或细支气管的分泌细胞。为了确定黏液细胞和浆液性上皮细胞在哺乳动物气管上皮中是否普遍存在，我们对六个物种的气管上皮细胞的超微结构和细胞群体密度进行了表征：仓鼠（H）、大鼠（Rt）、兔子（Rb）、猫（C）、冠毛猕猴（M. radiata）（B）和绵羊（S）。通过气道灌注戊二醛/多聚甲醛进行固定后，采用选择性包埋技术对气管组织进行光镜和电镜（EM）处理。通过光镜对软骨上方的气管上皮进行定量，并通过透射电镜进行表征。黏液细胞的定义为具有丰富的大型非均匀颗粒、众多高尔基体复合体、位于基部的细胞核和颗粒内质网（GER）。气管上皮中黏液细胞的百分比为：仓鼠（0%）、大鼠（0.5%）、兔子（1.3%）、猫（20.2%）、冠毛猕猴（8%）、绵羊（5.1%）。浆液性细胞具有均匀的、电子致密的颗粒和广泛的GER。浆液性细胞仅存在于大鼠中（39.2%）。克拉拉细胞具有均匀的电子致密颗粒、丰富的无颗粒内质网（AER）和基部GER。在仓鼠（41.4%）和兔子（17.6%）中发现了克拉拉细胞。在绵羊气管中，35.9%的上皮细胞具有小的电子透亮颗粒、丰富的AER和众多高尔基体复合体。在冠毛猕猴气管中，16%的上皮细胞具有小的电子透亮颗粒、众多多核糖体、核周高尔基体和中等量的GER。在猫气管中，5.4%的上皮细胞没有颗粒，具有中等数量的线粒体、中等量的多核糖体、一个位于中央的细胞核和长的腔面微绒毛。基部细胞、纤毛细胞和非纤毛细胞在气管上皮细胞群体中所占的百分比为：仓鼠（5.6%、47.5%、46.7%）、大鼠（13.4%、40.6%、45.9%）、兔子（28.2%、43.0%、28.3%）、猫（37.3%、36.1%、26.7%）、冠毛猕猴（31%、41%、28%）、绵羊（28.5%、30.6%、41%）。我们得出以下结论：1）黏液细胞和浆液性细胞并非所有哺乳动物物种气管上皮衬里所共有；2）气管分泌细胞的丰度、分布和超微结构存在显著的种间异质性；3）非纤毛细胞在气管功能中的潜在作用在气管上皮细胞群体内部以及不同物种之间存在差异。
