Oravec S, Ronda N, Carayon A, Milliez J, Kazatchkine M D, Hornych A
INSERM U-430, Hôpital Broussais, Paris, France.
Nephrol Dial Transplant. 1995;10(6):796-800.
We have analysed the in-vitro effect of pooled normal polyspecific immunoglobulin G (IVIg) and F(ab')2 fragments of IVIg on the secretion of prostacyclin (PGI2), thromboxane A2 (TxA2), and endothelin from cultured human umbilical vein endothelial cells. The stable metabolites, 6-keto-PGF1 alpha and TxB2, as well as endothelin, were measured by radioimmunoassay after extraction from the culture supernatants. IVIg inhibited TxB2 and endothelin secretion in a dose-dependent manner, but not that of 6-keto-PGF1 alpha. Therefore the ratio of 6-keto-PGF1 alpha/TxB2 increased (+600%). The effect of F(ab')2 fragments prepared from IVIg was similar to that observed with IVIg, indicating that the effect of IVIg was mediated by the variable region of immunoglobulin. The results suggest that part of the effects of IVIg in inflammatory vasculitis may be due to a modification of the PGI2/TxA2 ratio and inhibition of endothelin secretion, and that natural IgG antibodies may participate in the homeostatic process of endothelium under physiological conditions.
我们分析了混合的正常多特异性免疫球蛋白G（静脉注射免疫球蛋白，IVIg）及其F(ab')2片段对培养的人脐静脉内皮细胞分泌前列环素（PGI2）、血栓素A2（TxA2）和内皮素的体外作用。从培养上清液中提取后，通过放射免疫分析法测定稳定代谢产物6-酮-前列腺素F1α（6-keto-PGF1α）、血栓素B2（TxB2）以及内皮素。IVIg以剂量依赖方式抑制TxB2和内皮素分泌，但不抑制6-keto-PGF1α的分泌。因此，6-keto-PGF1α/TxB2的比值增加（+600%）。从IVIg制备的F(ab')2片段的作用与IVIg观察到的作用相似，表明IVIg的作用是由免疫球蛋白的可变区介导的。结果表明，IVIg在炎症性血管炎中的部分作用可能归因于PGI2/TxA2比值的改变和内皮素分泌的抑制，并且天然IgG抗体可能在生理条件下参与内皮细胞的稳态过程。
