{"title":"冷却对大鼠主动脉α -1肾上腺素能受体机制的影响。","authors":"I Takayanagi, K Koike, M Nakamura, Y Horie","doi":"","DOIUrl":null,"url":null,"abstract":"<p><p>1. The effects of cooling from 37 degrees C to 25 degrees C on alpha-1-adrenoceptor mechanisms in isolated rat aortic strips were studied. 2. The dissociation constant and the maximum binding for [3H]-prazosin, and the pA2-values (negative logarithm of dissociation constant) of clonidine and prazosin against noradrenaline were not influenced by cooling. 3. These results indicate that cooling did not influence the affinity of a competitive antagonist and receptor concentration. 4. Cooling increased the dissociation constant of noradrenaline but decreased its efficacy. 5. A receptor occupancy-response curve for noradrenaline was a rectangular hyperbola at 37 degrees C but linear at 25 degrees C, suggesting that a relationship between the contractile response and receptor occupancy was changed by cooling.</p>","PeriodicalId":10579,"journal":{"name":"Comparative biochemistry and physiology. C, Comparative pharmacology and toxicology","volume":"90 1","pages":"95-9"},"PeriodicalIF":0.0000,"publicationDate":"1988-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Effects of cooling on alpha-1-adrenoceptor mechanisms in rat aorta.\",\"authors\":\"I Takayanagi, K Koike, M Nakamura, Y Horie\",\"doi\":\"\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p><p>1. The effects of cooling from 37 degrees C to 25 degrees C on alpha-1-adrenoceptor mechanisms in isolated rat aortic strips were studied. 2. The dissociation constant and the maximum binding for [3H]-prazosin, and the pA2-values (negative logarithm of dissociation constant) of clonidine and prazosin against noradrenaline were not influenced by cooling. 3. These results indicate that cooling did not influence the affinity of a competitive antagonist and receptor concentration. 4. Cooling increased the dissociation constant of noradrenaline but decreased its efficacy. 5. A receptor occupancy-response curve for noradrenaline was a rectangular hyperbola at 37 degrees C but linear at 25 degrees C, suggesting that a relationship between the contractile response and receptor occupancy was changed by cooling.</p>\",\"PeriodicalId\":10579,\"journal\":{\"name\":\"Comparative biochemistry and physiology. C, Comparative pharmacology and toxicology\",\"volume\":\"90 1\",\"pages\":\"95-9\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"1988-01-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Comparative biochemistry and physiology. C, Comparative pharmacology and toxicology\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Comparative biochemistry and physiology. C, Comparative pharmacology and toxicology","FirstCategoryId":"1085","ListUrlMain":"","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
Effects of cooling on alpha-1-adrenoceptor mechanisms in rat aorta.
1. The effects of cooling from 37 degrees C to 25 degrees C on alpha-1-adrenoceptor mechanisms in isolated rat aortic strips were studied. 2. The dissociation constant and the maximum binding for [3H]-prazosin, and the pA2-values (negative logarithm of dissociation constant) of clonidine and prazosin against noradrenaline were not influenced by cooling. 3. These results indicate that cooling did not influence the affinity of a competitive antagonist and receptor concentration. 4. Cooling increased the dissociation constant of noradrenaline but decreased its efficacy. 5. A receptor occupancy-response curve for noradrenaline was a rectangular hyperbola at 37 degrees C but linear at 25 degrees C, suggesting that a relationship between the contractile response and receptor occupancy was changed by cooling.