The thiol-oxidizing agent diamide reduces isoproterenol-stimulated amylase release in rat parotid acinar cells.
In parotid acinar cells, activation of beta-adrenergic receptors provokes exocytotic amylase release via the accumulation of intracellular cAMP. Cellular redox status plays a pivotal role in the regulation of various cellular functions. Cellular redox imbalance caused by the oxidation of cellular antioxidants, as a result of oxidative stress, induces significant biological damages. In this study, we examined effect of diamide, a thiol-oxidizing reagent, on amylase release in rat parotid acinar cells. In the presence of diamide, isoproterenol (IPR)-induced cAMP formation and amylase release were partially reduced. Diamide had no effect on amylase release induced by forskolin and mastoparan, an adenylate cyclase activator and heterotrimeric GTP binding protein activator, respectively. In the cells pretreated with diamide, the binding affinity of [(3)H]dihydroalprenolol to beta-receptors was reduced. These results suggest that oxidative stress results in reduction of binding affinity of ligand on beta-receptor and consequently reduces protein secretory function in rat parotid acinar cells.
Guo
Ming-Yu
MY
Department of Physiology, Nihon University School of Dentistry at Matsudo, Matsudo, Japan.
Narita
Takanori
T
Qi
Bing
B
Satoh
Keitaro
K
Katsumata-Kato
Osamu
O
Matsuki-Fukushima
Miwako
M
Fujita-Yoshigaki
Junko
J
Sugiya
Hiroshi
H
D000681:Amylases / Q000378:metabolism*; D000818:Animals; D000242:Cyclic AMP / Q000378:metabolism; D003958:Diamide / Q000494:pharmacology*; D007545:Isoproterenol / Q000494:pharmacology*; D010084:Oxidation-Reduction; D018384:Oxidative Stress / Q000502:physiology; D010306:Parotid Gland / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D051381:Rats; D011943:Receptors, Adrenergic, beta / Q000378:metabolism; D013438:Sulfhydryl Compounds / Q000378:metabolism*; D013566:Sympathomimetics / Q000494:pharmacology*
D011943:Receptors, Adrenergic, beta; D013438:Sulfhydryl Compounds; D013566:Sympathomimetics; D003958:Diamide; D000242:Cyclic AMP; D000681:Amylases; D007545:Isoproterenol