Scanning Electron Microscopical Observation on the Mucosal Epithelium of Hens' Oviduct with Special Reference to the Transport Mechanism of Spermatozoa through the Oviduct

鶏の卵管粘膜上皮の構造と,これに関連して卵管内の精子移動の機構を,走査電子顕微鏡を用いて形態的に観察した。

卵管の粘膜上皮は,卵管の全長にわたって線毛細胞と非線毛細胞の2種の細胞から構成されていた。しかしこの両細胞の細胞形態,分布状態は,卵管の各部位によってかなり異なっていた。とくに漏斗部と子宮・腔移行部は類似の上皮構造をもっており,ここでは非線毛細胞を欠き,線毛細胞のみから成っているのが特徴であった。

一方,実験的に卵管腔部に注入された精子は・漏斗部と子宮・腔移行部に選択的に貯溜する傾向がみられた。この両部への精子の貯溜は,該部の線毛細胞の強力な線毛運動によって精子の前進が阻止されるためと推察された。

The mucosal epithelium of the oviduct in laying hens was studied by scanning electron microscopy. It was constructed principally by ciliated and nonciliated cells over its whole length. The distribution and appearance of these two types of epithelial cells varied considerably from one region of the oviduct to another. The infundibulum and the uterovaginal junction were characterized by the distribution of only ciliated cells having abundant, somewhat low cilia, different from any other region of the oviduct.

The spermatozoa introduced experimentally into the vagina were retarded and retained selectively in the lumina of these two regions of the oviduct. They were located among the cilia of ciliated cells. A barrier mechanism in the two regions against the spermatozoal transport through the oviduct in hens, which has been suggested by early workers, appeared to be a structural characteristic of the mucosal epithelium. The strong ciliary movement of the two regions may act as a simple mechanical barrier against the upward progress of spermatozoa and serve to make a "sperm nest" of these regions.