W. Greil, G. Niedernhuber, D. Stübner, R. Gärtner
{"title":"EGF对甲状腺滤泡cAMP形成的抑制作用是由细胞内ca2 ++介导的。","authors":"W. Greil, G. Niedernhuber, D. Stübner, R. Gärtner","doi":"10.1530/ACTA.0.114S267","DOIUrl":null,"url":null,"abstract":"The mechanism of cAMP-inhibition by EGF was studied in isolated porcine thyroid follicles. EGF inhibited TSH-induced cAMP-formation maximally by 40%, this effect remained up to 1 h of pre-incubation. The calcium-ionophore A 23 187 also inhibited cAMP-formation, but its effect was relieved after 1 h. The phorbolester TPA had a biphasic influence on cAMP-formation, with a transient increase (5 min) before a sustained inhibition (60 min); the inhibitory effect was mimicked by the diacylglycerol 1-oleoyl-2-acetyl-glycerol. Exogenous arachidonic acid had only a small and transient inhibitory effect on cAMP-formation. We conclude, that EGF inhibits cAMP-formation by a raise of intracellular Ca++, as well as by the direct activation of proteinkinase C, indicating, that a phosphorylated product could be a mediator for the inhibition of adenylate cyclase.","PeriodicalId":6931,"journal":{"name":"Acta endocrinologica. Supplementum","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"1987-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"5","resultStr":"{\"title\":\"Inhibition of cAMP formation by EGF in thyroid follicles is mediated by intracellular Ca++.\",\"authors\":\"W. Greil, G. Niedernhuber, D. Stübner, R. Gärtner\",\"doi\":\"10.1530/ACTA.0.114S267\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"The mechanism of cAMP-inhibition by EGF was studied in isolated porcine thyroid follicles. EGF inhibited TSH-induced cAMP-formation maximally by 40%, this effect remained up to 1 h of pre-incubation. The calcium-ionophore A 23 187 also inhibited cAMP-formation, but its effect was relieved after 1 h. The phorbolester TPA had a biphasic influence on cAMP-formation, with a transient increase (5 min) before a sustained inhibition (60 min); the inhibitory effect was mimicked by the diacylglycerol 1-oleoyl-2-acetyl-glycerol. Exogenous arachidonic acid had only a small and transient inhibitory effect on cAMP-formation. We conclude, that EGF inhibits cAMP-formation by a raise of intracellular Ca++, as well as by the direct activation of proteinkinase C, indicating, that a phosphorylated product could be a mediator for the inhibition of adenylate cyclase.\",\"PeriodicalId\":6931,\"journal\":{\"name\":\"Acta endocrinologica. Supplementum\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":0.0000,\"publicationDate\":\"1987-08-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"5\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Acta endocrinologica. Supplementum\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.1530/ACTA.0.114S267\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Acta endocrinologica. Supplementum","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1530/ACTA.0.114S267","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
Inhibition of cAMP formation by EGF in thyroid follicles is mediated by intracellular Ca++.
The mechanism of cAMP-inhibition by EGF was studied in isolated porcine thyroid follicles. EGF inhibited TSH-induced cAMP-formation maximally by 40%, this effect remained up to 1 h of pre-incubation. The calcium-ionophore A 23 187 also inhibited cAMP-formation, but its effect was relieved after 1 h. The phorbolester TPA had a biphasic influence on cAMP-formation, with a transient increase (5 min) before a sustained inhibition (60 min); the inhibitory effect was mimicked by the diacylglycerol 1-oleoyl-2-acetyl-glycerol. Exogenous arachidonic acid had only a small and transient inhibitory effect on cAMP-formation. We conclude, that EGF inhibits cAMP-formation by a raise of intracellular Ca++, as well as by the direct activation of proteinkinase C, indicating, that a phosphorylated product could be a mediator for the inhibition of adenylate cyclase.