Radioprotection of the rat parotid gland by WR-2721 and isoproterenol and its modification by propranolol.
The aminothiol WR-2721 and beta-adrenergic agonist isoproterenol both conferred considerable radioprotection to the rat parotid gland. Isoproterenol acts on the beta-receptor, and its specific antagonist, propranolol, eliminated isoproterenol's protective effect, implicating the beta-receptor and possibly cAMP in the mechanism of the protection. Since other sulfhydryl-containing protectants have been shown to elevate cAMP it was reasoned that WR-2721 might do so as well. However, the radioprotection conferred by WR-2721 was not reduced by propranolol, showing that the beta-receptor played no part in WR-2721's action. The possible role of cAMP in radioprotection by isoproterenol is discussed.
D004999:Amifostine / Q000494:pharmacology*; D000818:Animals; D004307:Dose-Response Relationship, Radiation; D004347:Drug Interactions; D007545:Isoproterenol / Q000494:pharmacology*; D009929:Organ Size / Q000528:radiation effects; D009946:Organothiophosphorus Compounds / Q000494:pharmacology*; D010306:Parotid Gland / Q000187:drug effects / Q000528:radiation effects*; D011433:Propranolol / Q000494:pharmacology*; D011836:Radiation Tolerance; D051381:Rats; D011919:Rats, Inbred Strains; D014965:X-Rays
D009946:Organothiophosphorus Compounds; D011433:Propranolol; D007545:Isoproterenol; D004999:Amifostine