Hendricks-Muñoz K D, Finkelstein J N, Shapiro D L
University of Rochester School of Medicine, Department of Pediatrics (Neonatology), New York 14642.
Exp Lung Res. 1989;15(1):63-76. doi: 10.3109/01902148909069609.
We investigated the involvement of membrane phospholipid methylation in receptor-mediated secretion of surfactant in adult rabbit type II alveolar epithelial cells (type II pneumocyte). Phospholipid methyltransferase activity was found in type II pneumocyte microsomes. Cell cultures of adult rabbit type II pneumocytes were then used to assay methyltransferase activity in the presence of the beta-adrenergic agonist, terbutaline, and the methyltransferase inhibitor, 3-deazaadenosine. Terbutaline predictably stimulated adenylate cyclase activity and surfactant secretion. It was also found to stimulate incorporation of methyl groups into phosphatidylcholine and to increase beta-adrenergic receptor availability as assayed by binding of dihydroalprenolol (DHA). Surfactant secretion, as well as adenylate cyclase activity, were stimulated by terbutaline and were inhibited by 3-deazaadenosine. 3-Deazaadenosine did not inhibit DHA binding. These results suggest that phospholipid methylation plays a role in stimulus-secretion coupling in adult rabbit type II pneumocytes.
我们研究了膜磷脂甲基化在成年兔II型肺泡上皮细胞（II型肺细胞）中受体介导的表面活性剂分泌过程中的作用。在II型肺细胞微粒体中发现了磷脂甲基转移酶活性。随后，我们利用成年兔II型肺细胞的细胞培养物，在β-肾上腺素能激动剂特布他林和甲基转移酶抑制剂3-脱氮腺苷存在的情况下测定甲基转移酶活性。不出所料，特布他林刺激了腺苷酸环化酶活性和表面活性剂分泌。还发现它能刺激甲基掺入磷脂酰胆碱，并通过二氢阿普洛尔（DHA）结合测定增加β-肾上腺素能受体的可用性。特布他林刺激了表面活性剂分泌以及腺苷酸环化酶活性，而3-脱氮腺苷则对其有抑制作用。3-脱氮腺苷不抑制DHA结合。这些结果表明，磷脂甲基化在成年兔II型肺细胞的刺激-分泌偶联中发挥作用。
