鲤、青鱼肠粘膜内分泌细胞的免疫组织化学鉴别和定位

IMMUNOHISTOCHEMICAL IDENTIFICATION AND LOCALIZATION OF ENDOCRINE CELLS IN THE INTESTINAL MUCOSA OF COMMON CARP AND BLACK CARP

使用过氧化物酶——抗过氧化物酶(PAP)的免疫组织化学染色技术,用10种哺乳动物激素培育出的抗血清对鲤、青鱼肠道粘膜中内分泌细胞的鉴別表明,它们的肠道粘膜上皮中存在有胃泌素、P物质、牛胰多肽、亮氨酸脑啡肽、胰高血糖素样免疫反应物、抑胃多肽等6种免疫活性內分泌细胞;而五羟色胺、胆囊收缩素和神经降压素没有免疫活性反应。在鲤的肠粘膜中存在生长抑素免疫活性内分泌细胞;青鱼中则未见到这种细胞。两种鱼的各种免疫活性內分泌细胞多数在前肠的分布密度较大;但青鱼肠粘膜中P物质和亮氨酸脑啡肽两种免疫活性内分泌细胞却在直肠中分布最多;胰高血糖素样免疫活性内分泌细胞在中肠分布最多。P物质和胃泌素免疫活性內分泌细胞大多数分布于肠褶顶部;其他各种免疫活性內分泌细胞则主要分布于肠褶的中、底部。本文比较了鲤、青鱼的肠内分泌细胞在各肠段中的分布密度,并对其形态学及分布特点进行描述和讨论。

Using immunohistochemical staining technique of the peroxidase-anti-peroxidase (PAP), 10 kinds of antisera raised against mammalian hormones were investigated with regard to the identification and distribution of endocrine cells in the intestinal mucosa of common carp(Cyprinus carpio) and black carp (Mylopharyngodon piceus). Endocrine cells in the intestinal mucosa of common carp reacting with antisera against 7 different mammalian polypeptide hormones were localized, and 6 kinds of antisera were localized in black carp. Positive reactions were obtained with antisera againt gastrin(GAS), substance P(SP), bovine pancreatic polypeptide(BPP), leucine enkephalin(ENK), glucag on-like immunoreactants(GLI), gastric inhibitery peptide (GIP), and somatostatine(SOM). No immunoreactivities were found with antisera against meurotensin(NT), 5-hydroxytryptamine(5-HT) and cholecystokinin(CCK) in the gut of common carp and black carp, or with antisera against somatostatine(SOM) in the gut of black carp. Most kinds of the immunoreactive endocrine cells had the highest distribution density in the anterior segment of the foregut of common carp and black carp. But in the gut of black carp, SP and ENK endocrine cells had the highest distribution density in the rectum, while GLI endocrine cells had the highest distribution density in the midgut. In common carp, BPP and ENK endocrine cells had the highest distribution density in the posterior segment of foregut, SP and GLI endocrine cells had the highest distribution density in the midgut, and none of the immunoreactive endocrine cells was found in the rectum. GAS and SP endocrine cells were mostly located in the top of the gut folds; the rest were mostly located in the basal and middle parts of the gut folds. Almost all kinds of immunoreactive endocrine cells were of the open type. In some endocrine cells, the basilar cytoplasmic process extended to the basement membrane and adjacent cells, and formed synapse-like contact with basement membrane. This phenomenon provided morphological evidence for neuroendocrine and paracrine secretion of enteroendocrine cells. It is noteworthy that SP, ENK and SOM are neural peptides, their immunoreactive endocrine cells were found in the intestinal mucosa of fishes. This phenomenon providesnew evidence for the concept of brain-gut peptides. In the present paper, the morphological, characteristics of immunoreactive endocrine cells were described. Their distribution density in all intestinal segments of common carp and black were compared. Their distribution characteristics, the possible way of secretion and function were discussed.