Department of Anatomy and Cell Biology, Faculty of Medicine, University of Cantabria, c/ Cardenal Herrera Oria, s/n, 39011 Santander, Spain.
Cell Tissue Res. 2012 Oct;350(1):143-56. doi: 10.1007/s00441-012-1462-0. Epub 2012 Jul 3.
We describe the structure of the spleen of the African lungfish Protopterus annectens in freshwater conditions, and after 6 months of aestivation. The spleen is formed by cortical tissue that surrounds the splenic parenchyma. The cortex is a reticulum that contains two types of granulocytes, developing and mature plasma cells, and melanomacrophage centres (MMCs). The parenchyma is divided into lobules that show a subcapsular sinus and areas of red pulp and white pulp. Red pulp contains vascular sinuses and atypical cords formed by delicate trabeculae. White pulp also contains vascular sinuses and cords. Structural data indicate that red pulp is involved in erythropoiesis, destruction of effete erythrocytes, and plasma cell differentiation. White pulp appears to be involved in the production of immune responses. Macrophages and sinus endothelial cells constitute the reticulo-endothelial system of the spleen. After aestivation, the number of MMCs increases, and spleen tissue is infiltrated by lymphocytes, granulocytes, and monocytes. Also, white pulp is reduced, and sinus endothelial cells undergo vacuolar degeneration. Lungfish spleen shares structural characteristics with secondary lymphoid organs of both ectothermic and endothermic vertebrates, but appears to have evolved in unique ways.
我们描述了非洲肺鱼 Protopterus annectens 在淡水条件下和经过 6 个月夏眠后的脾脏结构。脾脏由包围脾实质的皮质组织形成。皮质是一种包含两种类型的粒细胞、发育和成熟浆细胞以及黑素巨噬细胞中心（MMC）的网状结构。实质分为小叶，显示出被膜下窦和红髓和白髓区域。红髓包含血管窦和由纤细小梁形成的非典型索。白髓也包含血管窦和索。结构数据表明，红髓参与红细胞生成、衰老红细胞的破坏和浆细胞分化。白髓似乎参与了免疫反应的产生。巨噬细胞和窦内皮细胞构成脾脏的网状内皮系统。夏眠后，MMC 的数量增加，脾组织被淋巴细胞、粒细胞和单核细胞浸润。此外，白髓减少，窦内皮细胞发生空泡变性。肺鱼脾脏具有与变温动物和恒温动物的次级淋巴器官相似的结构特征，但似乎以独特的方式进化。
