Myrsén U, Ahrén B, Sundler F
Department of Medical Cell Research, University of Lund, Sweden.
Regul Pept. 1995 Dec 7;60(1):19-31. doi: 10.1016/0167-0115(95)00114-5.
Neuropeptide Y (NPY) is known to occur in adrenergic and non-adrenergic nerves in rat pancreatic islets. Analysis of islet extracts has revealed local NPY synthesis after glucocorticoid treatment. The cellular localisation of NPY expression in rat islets following dexamethasone treatment (2 mg/kg daily, for 12 days), was investigated by a combination of immunocytochemistry (ICC) and in situ hybridisation (ISH). NPY-immunoreactive nerve fibres were seen in pancreatic islets of both control and dexamethasone-treated rats. In the controls weak NPY immunoreactivity but no NPY mRNA was observed in occasional islets. After dexamethasone treatment, clusters of islet cells distributed both centrally and peripherally displayed intense NPY immunoreactivity and NPY mRNA labelling. Immunocytochemical double staining and ISH combined with ICC for NPY and islet hormones revealed that most NPY expressing cells were identical with insulin cells; a few cells were identical with somatostatin or pancreatic polypeptide (PP) cells. In contrast, glucagon cells seemed to be devoid of NPY immunoreactivity and NPY mRNA labelling. Thus, in the rat, glucocorticoids cause a marked upregulation of NPY expression in islet cells, preferentially the insulin cells. The expression of NPY might represent an islet adaptation mechanism to the reduced peripheral insulin sensitivity.
已知神经肽Y（NPY）存在于大鼠胰岛的肾上腺素能和非肾上腺素能神经中。对胰岛提取物的分析显示，糖皮质激素治疗后会出现局部NPY合成。通过免疫细胞化学（ICC）和原位杂交（ISH）相结合的方法，研究了地塞米松治疗（每日2 mg/kg，共12天）后大鼠胰岛中NPY表达的细胞定位。在对照大鼠和地塞米松治疗的大鼠胰岛中均可见到NPY免疫反应性神经纤维。在对照组中，偶尔在胰岛中观察到弱NPY免疫反应性，但未观察到NPY mRNA。地塞米松治疗后，集中分布和周边分布的胰岛细胞簇均显示出强烈的NPY免疫反应性和NPY mRNA标记。对NPY和胰岛激素进行免疫细胞化学双重染色以及ISH与ICC相结合的结果显示，大多数表达NPY的细胞与胰岛素细胞相同；少数细胞与生长抑素或胰多肽（PP）细胞相同。相比之下，胰高血糖素细胞似乎没有NPY免疫反应性和NPY mRNA标记。因此，在大鼠中，糖皮质激素会导致胰岛细胞中NPY表达显著上调，优先上调胰岛素细胞中的表达。NPY的表达可能代表胰岛对外周胰岛素敏感性降低的一种适应机制。
