期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1982
卷号：79
期号：21
页码：6470-6474
DOI：10.1073/pnas.79.21.6470
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：The effects of sodium nitroprusside, 8-bromo cyclic GMP, 8-bromoguanosine 5'-monophosphate, 8-bromo cyclic AMP, dibutyryl cyclic AMP, and isoproterenol on incorporation of 32P into proteins in intact rat thoracic aorta were studied. Aortas were incubated in [32P]orthophosphate in order to label endogenous adenosine triphosphate. Agents were then added for various times and the tissues were homogenized and fractionated (100,000 x g for 60 min) into soluble and particulate fractions. Soluble and particulate fractions were subjected to isoelectric focusing followed by sodium dodecyl sulfate/polyacrylamide gel electrophoresis and autoradiographs were made. Nitroprusside induced a concentration-dependent increase in incorporation of 32P into nine proteins and a decrease in 32P incorporation into two proteins. Some of these proteins appeared in both the soluble and particulate fractions of homogenates; others appeared only in the soluble fraction. The pattern of 32P incorporation was identical after 2- or 15-min exposure to nitroprusside and was mimicked by exposure to 50-500 {micro}M 8-bromo cyclic GMP. 8-Bromoguanosine 5'-monophosphate did not alter 32P incorporation. Dibutyryl cyclic AMP at 50 {micro}M had no effect upon 32P incorporation whereas a higher concentration (0.5 mM) caused increased or decreased 32P incorporation into some, but not all, of the same proteins. 8-Bromo cyclic AMP (5 mM) produced only small changes in 32P incorporation. The pattern of 32P incorporation induced by a relatively high concentration of isoproterenol 0.1 mM was similar but not identical to that seen with 0.5 mM dibutyryl cyclic AMP. The present study indicates that the incorporation of 32P into endogenous proteins of intact rat aorta can be regulated by nitroprusside. These effects can be mimicked by cyclic GMP analogues and only partially by cyclic AMP analogues or isoproterenol. Presumably, these effects of nitroprusside are mediated through a cyclic GMP-dependent process (protein kinase or phosphatase) which may play a role in the relaxant properties of nitroprusside and cyclic GMP.
