Autoradiographic localization of changes in pulmonary beta-adrenoceptors in an animal model of atopy.
Vaccination of guinea pigs with Haemophilus influenzae leads to an impairment of beta-adrenoceptor function in lung. We have used an autoradiographic technique to study the distribution of changes in lung beta-adrenoceptor density. H. influenzae induced a decrease in beta-adrenoceptors in peripheral lung membranes of 22 +/- 5% (mean +/- S.E.M., n = 7), while the affinity of binding was unaffected. Tracheal beta-adrenoceptor binding was not influenced by H. influenzae. Autoradiography revealed a 27% reduction in beta-adrenergic binding sites on alveolar septa. Bronchial epithelial beta-adrenoceptors were decreased for 36%, and vascular smooth muscle and endothelial beta-adrenoceptors were also reduced. beta-Adrenoceptors on airway smooth muscle were unaffected. H. influenzae affected both the beta 1- and beta 2-subtypes of receptors. It is concluded that in this animal model of atopy beta-adrenoceptors may be decreased on several different cell types within the lungs, which may influence overall airway and vascular reactivity.
Engels
F
F
Department of Veterinary Pharmacology, University of Utrecht, The Netherlands.
Carstairs
J R
JR
Barnes
P J
PJ
Nijkamp
F P
FP
D000818:Animals; D001345:Autoradiography; D006168:Guinea Pigs; D006192:Haemophilus Infections / Q000378:metabolism*; D006193:Haemophilus influenzae; D066298:In Vitro Techniques; D020120:Iodocyanopindolol; D008168:Lung / Q000378:metabolism*; D008297:Male; D008566:Membranes / Q000378:metabolism; D009130:Muscle, Smooth / Q000187:drug effects / Q000378:metabolism; D010869:Pindolol / Q000031:analogs & derivatives; D011943:Receptors, Adrenergic, beta / Q000187:drug effects / Q000378:metabolism*; D012130:Respiratory Hypersensitivity / Q000209:etiology / Q000378:metabolism*; D014132:Trachea / Q000378:metabolism
D011943:Receptors, Adrenergic, beta; D020120:Iodocyanopindolol; D010869:Pindolol