新しい酵素化学的アプローチによる胃粘膜腸上皮化生の特徴と胃癌との相互関係

Special Features of Intestinal Metaplasia in Gastric Mucosa and its Relation to Gastic Cancer: By enzyme-histochemical approaches

　胃粘膜腸上皮化生は，胃，十二指腸の各種疾患との関連において，とりわけ分化型腺癌発生の背景的因子としての可能性に関し興味がもたれており，また，実験動物胃癌の随伴病変として観察¹⁾²⁾されるなど，胃癌との相互関係は重要視されている．しかし，両者の関係を論ずるには，胃癌はもちろん，とくに腸上皮化生の実態を十分に把握することが前提条件でなければならない．1883年，Kupfferが化生の存在を最初に報告³⁾して以来，今日まで腸上皮化生の実態の把握は，なお十分とは思えない．その原因の1つとして，化生の複雑な分布や酵素パターンが考えられるが，このような腸上皮化生について十分に理解するためには，従来のように病理形態学的研究方法だけにたよるのでは，一定の限界があるのは当然といえよう．そのために最近では，腸上皮化生の分布状態やその程度を正確に観察するために，酵素組織化学的研究方法が導入されてきた^4)～7)．化生の指標酵素の組織化学的呈色反応を利用して，化生の存在を肉眼的に観察する方法である．最近，著者はLeucine aminopeptidase（aminopeptidase（cytosol），EC3.4.11.1.）を指標としたいわゆるLAP染色法⁸⁾およびAlkaline phosphatase（EC3.1.3.1.）を指標とするALP染色法との重染色法を考案し報告した⁹⁾¹⁰⁾．この新しいアプローチによって観察した胃粘膜腸上皮化生（以下化生と略）の特徴と癌病巣との相互関係を検討したので，若干の考察を加えて報告する．

　The degree of intestinal metaplasia and its distribution in gastric mucosa were examined by enzymehistochemical approaches as a supplement to histological studies. Leucine aminopeptidase and alkaline phosphatase were used as marker enzymes. The metaplasia which had no LAP activity was not found. Metaplasia was divided into two kinds according to the activity of ALP. The metaplasia which had the activity of ALP was seen in the intermediate zone and the adjacent area to gastroduodenal junction. The metaplasia without the activity of ALP was seen in cardiac and antral portions. The former was morphologically mature with many Paneth cells and well depeloped epithelium. The latter was immature with few Paneth cells and poorly developed epithelium.

　Gastric mucosa containing differentiated tubular adenocarcinoma and papillary carcinoma was associated with more intensive and extensive metaplasia. Furthermore, close correlation between site of lesion and area of metaplasia was confirmed. On the other hand, scanty or no metaplasia was seen in the cases of poorly differentiated carcinoma and signet ring cell carcinoma. No significant relation of these carcinomas to metaplasia was noted. Sixty one cases of early cancer and relatively small advanced cancer without diverse pathological findings were examined for this study. These facts were statistically highly reliable.