Hansson H A, Edwall D, Löwenadler B, Norstedt G, Paleus S, Skottner A
Department of Histology, University of Gothenburg, Sweden.
Acta Physiol Scand. 1988 Apr;132(4):569-76. doi: 10.1111/j.1748-1716.1988.tb08367.x.
Insulin-like growth factor I (IGF-I, somatomedin C) was mapped by immunocytochemistry in the pancreas of normal and experimentally influenced rats. The polyclonal IGF-I antiserum K 37 was characterized and demonstrated to be specific. In the exocrine pancreas some duct cells showed IGF-I immunoreactivity, other components being negative. The three main endocrine cell types in the islets of Langerhans were IGF-I immunoreactive, most strikingly the D cells. Hypophysectomy resulted in loss of IGF-I immunoreactivity in all three endocrine cell types, i.e. D, A and B cells, while the levels of somatostatin, glucagon and insulin, respectively, remained unchanged. Starvation seemed to increase and feeding to decrease the IGF-I immunoreactivity in the B cells. Cysteamine pre-treatment reduced the normally intense IGF-I and somatostatin immunoreactivities in the D cells. In rats made diabetic with alloxan or streptozotocin, the B cells were irreversibly damaged and lost both their insulin and IGF-I immunoreactivities, while the IGF-I immunoreactivity was increased in A cells; the D cells remained unchanged. The concentrations of IGF-I mRNA in the pancreas were almost equal in normal and alloxan diabetic rats as were the concentrations of extractable IGF-I. We conclude that IGF-I immunoreactive material can be demonstrated in adult animals in all endocrine islet cells, most prominently in the D cells. The expression of IGF-I immunoreactivity is in part under pituitary control. In the adult rat only one islet cell type synthesizes IGF-I immunoreactive material, i.e. the D cells, while, in contrast, the B cells are likely to be a major IGF-I source in fetal and neonatal islets.
采用免疫细胞化学方法对正常及经实验处理的大鼠胰腺中的胰岛素样生长因子I（IGF-I，生长调节素C）进行定位。对多克隆IGF-I抗血清K 37进行了特性鉴定，证明其具有特异性。在外分泌胰腺中，一些导管细胞显示出IGF-I免疫反应性，其他成分呈阴性。胰岛中的三种主要内分泌细胞类型均有IGF-I免疫反应性，其中D细胞最为明显。垂体切除导致所有三种内分泌细胞类型（即D、A和B细胞）中IGF-I免疫反应性丧失，而生长抑素、胰高血糖素和胰岛素的水平分别保持不变。饥饿似乎会增加，而喂食则会降低B细胞中的IGF-I免疫反应性。半胱胺预处理降低了D细胞中通常强烈的IGF-I和生长抑素免疫反应性。用四氧嘧啶或链脲佐菌素使大鼠患糖尿病后，B细胞受到不可逆损伤，失去了胰岛素和IGF-I免疫反应性，而A细胞中的IGF-I免疫反应性增加；D细胞保持不变。正常大鼠和四氧嘧啶糖尿病大鼠胰腺中IGF-I mRNA的浓度以及可提取IGF-I的浓度几乎相等。我们得出结论，在成年动物的所有内分泌胰岛细胞中均可检测到IGF-I免疫反应性物质，最显著的是在D细胞中。IGF-I免疫反应性的表达部分受垂体控制。在成年大鼠中，只有一种胰岛细胞类型合成IGF-I免疫反应性物质，即D细胞，而相比之下，B细胞可能是胎儿和新生儿胰岛中IGF-I的主要来源。
