神经垂体多肽激素在人胎儿胸腺组织的表达

Expression of neurohypophysial peptides in human fetal thymus

目的：探讨神经垂体激素在人胎儿胸腺组织的表达。方法：用放射免疫测定药盒测定人胎儿胸腺组织匀浆提取物中精氨酸升压素（ＡＶＰ）和催产素（ＯＴ）的含量，同时用免疫组化方法检测胎儿胸腺组织冷冻切片和石蜡切片中的ＡＶＰ和ＯＴ的表达。结果：人胎儿胸腺组织提取液中ＡＶＰ（１２例）和ＯＴ（１３例）的含量（ｐｇ／１００ｍｇ湿重组织）（ｘ±ｓ）分别为４７．６４±４５．１４和８３．３５±５５．８９。比较胎龄＜２０周组和≥２０周组的胸腺组织提取液中这两种多肽激素的含量，差异均无显著性（Ｐ＞０．０５）。免疫组化检测发现，胸腺组织中ＡＶＰ和ＯＴ阳性反应细胞的分布部位与角蛋白阳性反应细胞相一致，表明胸腺上皮细胞可表达这两种神经垂体多肽激素。结论：人胎儿胸腺在胎龄１６～２０周时即可表达神经垂体多肽激素ＡＶＰ和ＯＴ，胸腺上皮细胞是产生这两种神经多肽激素的主要细胞。

Objective:To investigate expression of neurohypophysial peptides in human fetal thymus.Methods:By using radioimmunoassay the concentrations of arginine vasopressin and oxytocin were evaluated in extracts of human fetal thymus and immunohistochemistry technique was used to detect the expression of neurohypophysial peptides in fetal thymus section. Results:The concentrations (pg/100mg wet tissue) of AVP( n =12) and OT( n =13) in extracts of human fetal thymus were ( x±s )47.64±45.14 and 83.35±55.89,respectively.In both concentrations of AVP and OT in thymus extracts there were no significant differences between groups of<20 week and ≥20 week fetus( P >0.05). Immunohistochemistry employed in fetal thymus section revealed that most cells that were positively reactive to monoclonal antibodies against AVP and OT were consistent in location with the cells that reacted to keratin monoclonal antibody.Conclusions:This study demonstrated that neurohypophysial peptides AVP and OT in human fetal thymus expressed as earlier as at 16 to 20 week fetus. The sources of neurohypophysial peptides generated in fetal thymus derived from thymic epithelial cells.