Distribution of Endocrine Cells in Duck Digestive Tracts

食道から直腸末端までのアヒル消化管における内分泌細胞の存在と分布を,鉛ヘマトキシリン,塩酸トルイジンブルー,Sevier and Mungerの鍍銀法およびMassonの銀親和反応を用いて検索した。

鉛ヘマトキシリンと塩酸トルイジンブルーで染まる細胞は食道を除く消化管の全部位でみられ,好銀性細胞は腺胃粘膜,腺胃腺および腸管の全部位に,銀親和性細胞は腸管にのみみられた。

内分泌細胞の分布密度は,筋胃幽門部が最も多く,次が腺胃腺であり,腸は十二指腸,空腸,回腸,盲腸,結直腸の5部位とも同程度で幽門部の約1/2,腺胃粘膜および胃峡部は腺胃腺の1/10,筋胃中央部は前2部位よりも少なく最少であった。

筋胃幽門部は,筋胃と十二指腸を分けるわずかな粘膜ひだから筋胃側5㎜位の部分であり,この部に非銀親和性で非好銀性の内分泌細胞が高密度に存在することは興味ある所見である。

これら内分泌細胞の染色性および分布から,アヒル消化管における4種類以上の内分泌細胞の存在が推測された。

The four histological methods, previously known to be useful in selective detection of endocrine cells, were applied to the duck digestive tracts, from oesophagus to colorectum. Cells stained with lead-hematoxylin and HC1-toluidine blue were observed in all regions of the duck digestive tracts with the exception of the oesophagus. Argyrophil cells were observed in proventricular mucosa and glands, and in the intestine. Argentaffin cells were observed only in the intestine.

The frequency of endocrine cells in the duck digestive tracts was highest in the restricted region of gizzard mucosa where was called the pyloric region in this paper, next in the proventricular glands, equally about half of the frequency in the pyloric region in the five regions of the intestine, one tenth of that of the proventricular glands in the proventricular and isthmus mucosa, and the smallest frequency was noted in the central part of gizzard mucosa.

The pyloric region was about 5mm anterior to the narrow mucosal fold separating the gizzard from the intestine. It was an interesting to find that the endocrine cells which were nonargentaffin and nonargyrophil were densely present in this region.

From the staining properties and the distribution of the endocrine cells, the possibility of existence of four and more types of endocrine cells in the duck digestive tracts was discussed.