Correlation between isoprenaline-stimulated synthesis of cyclic AMP and occurrence of beta-adrenoreceptors in immature erythrocytes from rats.
When increasing reticulocytosis (up to 80%) was induced in rats by treatment with acetyl-phenylhydrazine (up to 70 mg/kg on 3 consecutive days) synthesis of cAMP stimulated by isoprenaline in intact red blood cells and in the related membrane preparations increased up to 100-fold. At the same time the density of beta-adrenoreceptor sites (measured by ligand binding with (3H)(-)-dihydroalprenolol) in the related membrane preparations was only increased about 5-fold. There was however a linear correlation between the increase of isoprenaline-stimulated enzyme activity and the receptor density in membrane preparations. The results indicate that mature red cells contain beta-adrenoreceptor sites but little or not adenyl cyclase activity. Thus, during the maturation process of these cells, enzyme activity and receptor densities decrease at different speeds indicating a different turnover of these two entities of the cytoplasmic membrane.
D000262:Adenylyl Cyclases / Q000097:blood; D000526:Alprenolol / Q000031:analogs & derivatives / Q000378:metabolism; D000818:Animals; D000242:Cyclic AMP / Q000096:biosynthesis*; D004912:Erythrocytes / Q000187:drug effects / Q000378:metabolism*; D066298:In Vitro Techniques; D007545:Isoproterenol / Q000494:pharmacology*; D008297:Male; D051381:Rats; D011941:Receptors, Adrenergic / Q000378:metabolism*; D011943:Receptors, Adrenergic, beta / Q000378:metabolism*; D012156:Reticulocytes / Q000378:metabolism; D013268:Stimulation, Chemical
D011941:Receptors, Adrenergic; D011943:Receptors, Adrenergic, beta; D000526:Alprenolol; D000242:Cyclic AMP; D000262:Adenylyl Cyclases; D007545:Isoproterenol