Ito S, Suzuki T, Izumi T, Momotsu T, Isemura S, Saitoh E, Sanada K, Shibata A
Acta Endocrinol (Copenh). 1985 Jan;108(1):119-29. doi: 10.1530/acta.0.1080119.
In order to clarify the intracellular localization of salivary peptide P-C-like immunoreactivity in human pancreatic B-cells, an immunohistochemical study at electron microscopic levels was carried out by the protein A-gold technique using antisera against insulin and salivary peptide P-C. Both salivary peptide P-C-like immunoreactivity and insulin-like immunoreactivity were present only in the insulin secretory granules of the pancreatic B-cells. However, the former immunoreactivity was lacking in many insulin secretory granules of foetal pancreatic B-cells while the latter immunoreactivity was seen in all insulin secretory granules. Salivary peptide P-C-like immunoreactivity was not found in the other kinds of cells in the islets. In a previous immunohistochemical study at light microscopic level, salivary peptide P-C-like immunoreactivity appeared in a few pancreatic B-cells at about the 16th week of gestation, in an increasing number during gestation, and was seen in all pancreatic B-cells a few months after birth. The present finding together with the above results suggest that absence of salivary peptide P-C-like immunoreactivity in some foetal pancreatic B-cells may be due to the underdevelopment of salivary peptide P-C-like immunoreactivity in each insulin secretory granule. From the examination of cross-reactivity of antisera against salivary peptide P-C to other kinds of salivary peptides and salivary Protein C, and from the results of an indirect immunofluorescence technique using three kinds of antisera including antisera against salivary peptide P-C, salivary peptide P-B and salivary Protein C, it was thought that salivary peptide P-C-like immunoreactivity in human pancreatic B-cells belongs neither to salivary Protein C nor to salivary peptide P-B nor to salivary peptide P-E, but either to salivary peptide P-C itself or to an unknown substance which has common antigenic determinants with salivary peptide P-C, salivary peptide P-B and salivary Protein C. Salivary peptide P-C-like immunoreactivity was not found in the pancreatic B-cells of other mammals. Thus, although a new substance other than insulin is present in the insulin secretory granules of the human pancreatic B-cells, its pathophysiological function remains unclear.
为了阐明人胰腺β细胞中唾液肽P-C样免疫反应性的细胞内定位，采用蛋白A-金技术，使用抗胰岛素和唾液肽P-C的抗血清，在电子显微镜水平上进行了免疫组织化学研究。唾液肽P-C样免疫反应性和胰岛素样免疫反应性仅存在于胰腺β细胞的胰岛素分泌颗粒中。然而，胎儿胰腺β细胞的许多胰岛素分泌颗粒中缺乏前者的免疫反应性，而后者的免疫反应性在所有胰岛素分泌颗粒中均可见。在胰岛的其他类型细胞中未发现唾液肽P-C样免疫反应性。在先前的光镜免疫组织化学研究中，唾液肽P-C样免疫反应性在妊娠约16周时出现在少数胰腺β细胞中，在妊娠期间数量增加，并在出生后几个月出现在所有胰腺β细胞中。目前的发现与上述结果表明，一些胎儿胰腺β细胞中缺乏唾液肽P-C样免疫反应性可能是由于每个胰岛素分泌颗粒中唾液肽P-C样免疫反应性发育不全所致。通过检测抗唾液肽P-C抗血清与其他种类唾液肽和唾液蛋白C的交叉反应性，以及使用包括抗唾液肽P-C、唾液肽P-B和唾液蛋白C抗血清在内的三种抗血清的间接免疫荧光技术结果，认为人胰腺β细胞中的唾液肽P-C样免疫反应性既不属于唾液蛋白C，也不属于唾液肽P-B或唾液肽P-E，而是属于唾液肽P-C本身或与唾液肽P-C、唾液肽P-B和唾液蛋白C具有共同抗原决定簇的未知物质。在其他哺乳动物的胰腺β细胞中未发现唾液肽P-C样免疫反应性。因此，尽管人胰腺β细胞的胰岛素分泌颗粒中存在除胰岛素以外的新物质，但其病理生理功能仍不清楚。
