[Effect of eosinophil peroxidase on beta-adrenergic receptor-adenylate cyclase system].
We studied the effect of eosinophil peroxidase (EPO) on beta-adrenergic receptor (BAR)-adenylate cyclase system based on the hypothesis that eosinophils may participate in the pathogenesis of beta-blockade in acute asthma. The effect of EPO on BAR density on guinea pig lung membrane was studied first. The BAR density was decreased significantly by 10(-4) M H2O2 alone. EPO combined with 10(-4) M H2O2 and iodide caused additional decrease in BAR density, and the decrease was EPO concentration-dependent (1-10 U/ml). The effect of EPO on cyclic AMP (CAMP) accumulation in S49 cells was studied next. The CAMP accumulation with 10(-4) M isoproterenol was significantly inhibited with combination of EPO and H2O2, and the decrease was again EPO concentration-dependent (0.1-1 U/ml) without any changes in BAR density on the cells. Thus, EPO was demonstrated to have an influence on the BAR-adenylate cyclase system.
Motojima
S
S
Department of Medicine, Dokkyo University School of Medicine.
Toda
M
M
Fukuda
T
T
Makino
S
S
D000262:Adenylyl Cyclases / Q000378:metabolism*; D000818:Animals; D001249:Asthma / Q000209:etiology / Q000378:metabolism; D000242:Cyclic AMP / Q000378:metabolism; D047209:Eosinophil Peroxidase; D006168:Guinea Pigs; D066298:In Vitro Techniques; D007545:Isoproterenol / Q000037:antagonists & inhibitors; D008168:Lung / Q000378:metabolism*; D008223:Lymphoma / Q000378:metabolism; D051379:Mice; D010544:Peroxidases / Q000494:pharmacology / Q000502:physiology*; D011943:Receptors, Adrenergic, beta / Q000378:metabolism*; D014407:Tumor Cells, Cultured
D011943:Receptors, Adrenergic, beta; D000242:Cyclic AMP; D047209:Eosinophil Peroxidase; D010544:Peroxidases; D000262:Adenylyl Cyclases; D007545:Isoproterenol