Effect of eosinophil peroxidase on beta-adrenergic receptor density on guinea pig lung membrane.
We studied whether eosinophil peroxidase (EPO), an eosinophil granule basic protein, can alter beta-adrenergic receptor (BAR) density on the guinea pig lung membrane. Lung membrane was first preincubated with 1-10 U/ml EPO and then incubated with 10(-4) M NaI and 10(-4) or 10(-6) M H2O2 for 2 hours. BAR density was determined using (-)125I-cyanopindolol. EPO combined with 10(-4) M H2O2 and I decreased the BAR density in a concentration-dependent manner. When only 10(-4) M H2O2 was used, the decrease in BAR density was small but significant. When compared to I, bromide was less effective and chloride alone was not effective. These results suggest that EPO is one of the factors responsible for beta-adrenergic blockade in asthma.
Motojima
S
S
Department of Medicine and Clinical Immunology, Dokkyo University School of Medicine, Tochigi, Japan.
Fukuda
T
T
Makino
S
S
D000818:Animals; D002458:Cell Fractionation; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D047209:Eosinophil Peroxidase; D004804:Eosinophils / Q000201:enzymology; D006168:Guinea Pigs; D006861:Hydrogen Peroxide / Q000494:pharmacology; D007700:Kinetics; D008168:Lung / Q000378:metabolism*; D010544:Peroxidases / Q000302:isolation & purification / Q000494:pharmacology*; D011943:Receptors, Adrenergic, beta / Q000187:drug effects / Q000378:metabolism*
D011943:Receptors, Adrenergic, beta; D006861:Hydrogen Peroxide; D047209:Eosinophil Peroxidase; D010544:Peroxidases