Regulatory effects on the functions of neutrophils by human salivary antimicrobial peptides, histatins

1.组胺素的定量测定及其性质研究建立了人唾液中组胺素的反相高效液相色谱测定方法。组蛋白与唾液中的高分子量酸性成分结合。来自健康受试者的全唾液中总组胺素的平均值为28.6 μ M，并且未观察到组胺素浓度的性别相关差异。组胺素分泌的昼夜变化无节律性。在pH 7.0下孵育时，唾液中的组胺素被唾液中存在的蛋白水解酶自动降解。在分泌的唾液中，组胺素5不是由组胺素3.2产生的。histatin对中性粒细胞产生H_2O_2的抑制作用在纤连蛋白包被的培养皿上加入fMLP，中性粒细胞产生H_2O_2，histatin呈剂量依赖性地抑制中性粒细胞产生H_2O_2，而对PMA诱导的H_2O_2产生无抑制作用。组胺素可通过中性粒细胞上的受体抑制H_2O_2的产生。这些结果表明，抗菌组蛋白不断分泌到口腔中，并保护口腔粘膜免受中性粒细胞产生的活性氧的影响。

1. Quantitative determination of histatins and their characterization.The assay method for histatins in human saliva using a reversed-phase high performance liquid chromatography has been developed. The histatins have been bound to the high-molecular mass acid components in saliva. A mean value of the total histatins in whole saliva from healthy subjects was 28.6 muM and sex related differences for the histatin concentration was not observed. Diurnal changes of the histatin secretion did not show rhythms. Histatins in the saliva were autodegraded by proteolytic enzymes present in the saliva, as incubated at pH 7.0. In secreted saliva, histatin 5 was not generated from histatin 3.2. Inhibition by histatins on H_2O_2 generation from neutrophils.Neutrophils generated H_2O_2 in the addition of fMLP on the fibronectin-coated dish plate and this H_2O_2 production was inhibited by histatins dose-dependently, PMA-induced H_2O_2 generation was not inhibited by them. Histatins could inhibit the H_2O_2 generation via receptors on the neutrophils. On the other hand, histatins did not inhibit their chemotaxis and phagocytosis.These results suggest that antimicrobial histatins are secreted into the oral cavity constantly, and protect the oral mucous membrane from active oxygen generated by neutrophils.