胃癌乳酸脱氢酶同工酶细胞化学研究

Cytochemical study of lactate dehydrogenase isoenzymes in gastric cancer

目的探讨胃部细胞的代谢特点、异型增生与胃癌的关系以及胃癌生物学行为与乳酸脱氢酶（ＬＤＨ）同工酶的关系。方法应用酶细胞化学方法，观察５０例胃癌细胞ＬＤＨ同工酶的活性和分布。结果胃癌细胞ＬＤＨ总活性和Ｍ型ＬＤＨ明显高于主细胞、表面上皮和幽门腺上皮（Ｐ＜０００１），与异型增生上皮之间无显著性差异（Ｐ＞０２）。胃癌细胞Ｈ型ＬＤＨ低于主细胞、壁细胞和异型增生上皮（Ｐ＜００５），与表面上皮和幽门腺上皮之间无显著性差异（Ｐ＞００５）。胃癌细胞ＬＤＨ同工酶以Ｍ型为主。除分化型胃癌细胞Ｈ型ＬＤＨ阳性率高于未分化型胃癌（Ｐ＜００５）外，胃癌生物学行为与ＬＤＨ同工酶阳性率之间无明显关系（Ｐ＞００５）。结论胃癌细胞内ＬＤＨ及Ｍ型ＬＤＨ活性升高，同工酶以Ｍ型为主。Ｍ型ＬＤＨ升高可能与细胞增殖活性有关。Ｈ型ＬＤＨ可作为判断胃癌恶性程度的酶学指标。异型增生可能系正常胃粘膜与胃癌之间的一种交界性病变。

AIMS To study the relationship between lactate dehydrogenase (LDH) and LDH isoenzymes types M&H and biological behavior of gastric cancer. METHODS The activity and distribution of LDH and LDH isoenzymes types M&H in 50 cases of gastric cancer were observed with enzyme cytochemical method. RESULTS Total LDH and M_type LDH in gastric cancer cells were higher than in chief cells, surface epithelium, and pyloric glandular epithelium(P<0 01). There was no significant difference between total LDH and M_type LDH in dysplasia epithlium(P>0 2). H_type LDH in gastric cancer cells was lower than chief cells, parietal cells and dysplastic epithelium(P<0 05). There was no significant difference between H_type LDH in gastric cancer cells and in surface epithlium or pyloric glandular epithlium. LDH isoenzyme pattern in gastric cancer cells was dominated by M_type LDH. There was no association between biological behavior of gastric cancer and the positive rate of LDH isoenzymes except that the positive rate of H_type LDH in differentiated_type gastric cancer cells was higher than that in undifferentiated type gastric cancer cells(P<0 05). CONCLUSIONS Total LDH and M_type LDH in gastric cancer cells are elevated, LDH isoenzyme pattern is dominated by M_type LDH. The increase of M_type LDH is related to the proliferative activity of cells. H_type LDH can be used as an enzymological sign of determining malignant degrees. Dysplasia can be a borderline lesion between normal gastric mucosa and gastric cancer.