Stott W T, McKenna M J
Fundam Appl Toxicol. 1984 Aug;4(4):594-602. doi: 10.1016/0272-0590(84)90049-6.
Upper respiratory tract (URT) absorption of several compounds with differing water solubilities and potentials to cause lesions of the nasal mucosa were studied in rats. Absorption of propylene glycol monomethyl ether (PGME), PGME acetate (PGMEAc), ethyl acrylate (EA), epichlorohydrin (EPI), styrene (STY), nitroethane (NE), ethylene dibromide (EDB), and methylene chloride (MeCl2) vapors by the isolated URT was compared to that by the isolated lower respiratory tract (LRT) and the intact animal. Nearly all PGME and PGMEAc and 30-70% of EA, EPI, STY, NE, and EDB were absorbed when passed through the URT. In general, similar levels were absorbed by both the isolated LRT and intact animal. It was estimated that intact animals received more than 90% of their total dose of PGME and PGMEAc, and 50% of EA, NE, EPI, and EDB via the URT. Further, the dosage per unit of surface area in the URT may be 5000-6000 times that of the LRT. However, the extent of URT absorption was not related to the ability to cause lesions of the nasal mucosa. Absorption of compounds by the URT was not a simple function of water solubility or of blood or water/air partitioning coefficients suggesting that a more complex mechanism for controlling absorption may exist. In one case, it was demonstrated that URT enzymatic activity could influence the absorption of certain compounds by the URT.
在大鼠中研究了几种具有不同水溶性和导致鼻黏膜损伤潜力的化合物在上呼吸道（URT）的吸收情况。将丙二醇单甲醚（PGME）、丙二醇单甲醚乙酸酯（PGMEAc）、丙烯酸乙酯（EA）、环氧氯丙烷（EPI）、苯乙烯（STY）、硝基乙烷（NE）、二溴乙烷（EDB）和二氯甲烷（MeCl2）蒸气通过离体上呼吸道的吸收情况与通过离体下呼吸道（LRT）和完整动物的吸收情况进行了比较。当通过上呼吸道时，几乎所有的PGME和PGMEAc以及30%-70%的EA、EPI、STY、NE和EDB都被吸收。一般来说，离体下呼吸道和完整动物的吸收水平相似。据估计，完整动物通过上呼吸道接受的PGME和PGMEAc总剂量超过90%，EA、NE、EPI和EDB的总剂量超过50%。此外，上呼吸道单位表面积的剂量可能是下呼吸道的5000-6000倍。然而，上呼吸道的吸收程度与导致鼻黏膜损伤的能力无关。上呼吸道对化合物的吸收不是水溶性或血液或水/气分配系数的简单函数，这表明可能存在更复杂的吸收控制机制。在一个案例中，证明了上呼吸道的酶活性可以影响上呼吸道对某些化合物的吸收。
