Havran R T, Oster G
J Histochem Cytochem. 1977 Oct;25(10):1178-81. doi: 10.1177/25.10.72100.
Rat vaginal epithelial cells have trypsin-like activity as shown by the formation of a colored product when the cells are incubated with alpha-N-methyl alpha-N-toxyl-L-lysine beta-naphthol ester and hexazotized pararosanilin. This enzyme activity in vaginal smears is maximal at proestrus, i.e., the day in the 5-day estrus cycle when plasma estrogen is maximal. Only the rounded nucleated epithelial cells present at late diestrus, proestrus and early estrus demonstrate the trypsin-like enzyme activity. These are the cells that stain blue in the Papanicolaou method. Preincubation of cell suspensions with the serine protease inhibitor, p-nitrophenyl p-guanidino benzoate, prevented the enzyme staining reaction, further demonstrating the trypsin-like nature of the cellular enzyme. The advantages of this enzyme staining technique over the fibrin plate method for the demonstration of trypsin-like enzymes in cells are increased resolution and ability to show trypsin inhibitor effects.
当大鼠阴道上皮细胞与α-N-甲基-α-N-对甲苯磺酰-L-赖氨酸β-萘酚酯和六偶氮对苯二胺孵育时，会形成有色产物，这表明其具有胰蛋白酶样活性。阴道涂片的这种酶活性在动情前期最高，即在5天发情周期中血浆雌激素最高的那天。只有在动情后期、动情前期和动情早期出现的圆形有核上皮细胞表现出胰蛋白酶样酶活性。这些细胞在巴氏染色法中染成蓝色。用丝氨酸蛋白酶抑制剂对硝基苯基对胍基苯甲酸对细胞悬液进行预孵育，可阻止酶染色反应，进一步证明了细胞酶的胰蛋白酶样性质。与纤维蛋白平板法相比，这种酶染色技术在细胞中显示胰蛋白酶样酶的优势在于分辨率提高以及能够显示胰蛋白酶抑制剂的作用。
