Nikula K J, Lewis J L
Inhalation Toxicology Research Institute, Lovelace Biomedical and Environmental Research Institute, Inc., Albuquerque, New Mexico 87185.
Fundam Appl Toxicol. 1994 Nov;23(4):510-7. doi: 10.1006/faat.1994.1135.
Pyridine is a volatile solvent used as an intermediate in the production of insecticides, herbicides, pharmaceuticals, and dyes. Pyridine is also found in tobacco smoke. Because inhalation is a primary route of exposure to pyridine, we examined the effect of inhaled pyridine on morphology at the portal of entry, the nose. Nasal tissues from F344/N rats exposed using a nose-only mode 6 hr/day for 4 days to either filtered air (controls) or one of two concentrations of pyridine vapor were examined histologically. The rats had been killed 18 hr after the last exposure. The two pyridine concentrations were the current threshold limit value (TLV, 5 ppm) and a high concentration (444 ppm). Olfactory epithelial lesions in rats exposed to both concentrations of pyridine included vacuolar degeneration of sustentacular cells; focal, marked attenuation of the epithelium; loss of vacuolar degeneration of sustentacular cells; focal, marked attenuation of the epithelium; loss of neurons; and the presence of intraepithelial luminal structures. The lesions were only slightly more severe in the rats exposed to 444 ppm compared to those rats exposed to 5 ppm pyridine. The results show that inhalation of pyridine at the current TLV concentration of 5 or 444 ppm causes lesions in the olfactory epithelium of rats.
吡啶是一种挥发性溶剂，用作生产杀虫剂、除草剂、药品和染料的中间体。吡啶也存在于烟草烟雾中。由于吸入是接触吡啶的主要途径，我们研究了吸入吡啶对进入门户——鼻子的形态学影响。对采用仅鼻暴露模式、每天6小时、持续4天暴露于过滤空气（对照组）或两种浓度吡啶蒸气之一的F344/N大鼠的鼻组织进行了组织学检查。在最后一次暴露后18小时处死大鼠。两种吡啶浓度分别为当前阈限值（TLV，5 ppm）和高浓度（444 ppm）。暴露于两种浓度吡啶的大鼠的嗅觉上皮病变包括支持细胞的空泡变性；上皮的局灶性、明显变薄；支持细胞空泡变性的丧失；上皮的局灶性、明显变薄；神经元的丧失；以及上皮内管腔结构的存在。与暴露于5 ppm吡啶的大鼠相比，暴露于444 ppm的大鼠的病变仅略严重一些。结果表明，吸入当前TLV浓度为5 ppm或444 ppm的吡啶会导致大鼠嗅觉上皮出现病变。
