Glasø M, Ree K, Iversen O H, Hovig T
Virchows Arch B Cell Pathol Incl Mol Pathol. 1986;50(4):355-72. doi: 10.1007/BF02889914.
Epidermal "dark cells" (DC) are believed to play a specific role in the so-called promotion phase of experimental skin carcinogenesis. They are recognized by their morphological features both at the light and the electron microscopical level. The possible effects of fixation on the morphology of epidermal cells and hence on the number of DC have not yet been thoroughly studied. In the present light microscopical study we used a semiquantitative method together with simple cell counting to evaluate the influence of fixation on the specific cellular morphology which is traditionally used to determine the number of DC. The use of cacodylate vehicled prefixatives, either formaldehyde or glutaraldehyde, led to a higher incidence of DC, and furthermore both to an increased width of the intercellular spaces (ICS) and a more heavy staining of the keratinocytes than when s-collidine vehicled glutaraldehyde was used. Differences in yield of DC solely due to the prefixative itself (formaldehyde or glutaraldehyde) were not detected. Exposure to TPA or the use of a hyperosmolal prefixative vehicle both yielded higher DC numbers than did controls or conventional prefixative vehicles, respectively. After prefixation with hyperosmolal vehicles, however, TPA treatment did not induce higher DC yield than in a control series. Phenomena usually accompanying exposure to TPA, such as intercellular oedema (widening of the ICS) and cytoplasmic vacuolization, varied in parallel to the number of DC. Hence, there is reason to believe that the induction of epidermal DC is mainly associated with volume reduction of keratinocytes. Such shrinkage may be due to the cytotoxic properties of TPA and degenerative phenomena appearing during tissue processing.
表皮“暗细胞”（DC）被认为在实验性皮肤致癌作用的所谓促进阶段发挥特定作用。它们在光学和电子显微镜水平上都通过其形态特征得以识别。固定对表皮细胞形态以及因此对DC数量的可能影响尚未得到充分研究。在本光学显微镜研究中，我们使用一种半定量方法并结合简单的细胞计数来评估固定对传统上用于确定DC数量的特定细胞形态的影响。使用含有二甲胂酸盐的固定剂，无论是甲醛还是戊二醛，都会导致DC的发生率更高，而且与使用含有s - 可力丁的戊二醛相比，细胞间隙（ICS）宽度增加，角质形成细胞染色更深。未检测到仅由固定剂本身（甲醛或戊二醛）导致的DC产量差异。与对照组或传统固定剂载体相比，暴露于佛波酯（TPA）或使用高渗固定剂载体分别产生了更高的DC数量。然而，在用高渗载体进行预固定后，TPA处理并未比对照组诱导出更高的DC产量。通常伴随暴露于TPA的现象，如细胞间水肿（ICS增宽）和细胞质空泡化，与DC数量平行变化。因此，有理由相信表皮DC的诱导主要与角质形成细胞体积减小有关。这种收缩可能是由于TPA的细胞毒性特性以及组织处理过程中出现的退行性现象。
