Albuterol-induced downregulation of Gsα accounts for pulmonary β₂-adrenoceptor desensitization in vivo
J. Clin. Invest. Paul A. Finney, et al. 106:125 doi:10.1172/JCI8374 [Go to this article.]

Figure 1
Dose dependence and reproducibility of ACh-induced bronchoconstriction in anesthetized rats treated chronically with albuterol. Rats were implanted subcutaneously with osmotic minipumps delivering saline (filled circles/open bars) or albuterol (open circles/filled bars; 40 μg/kg/h). After 7 days, animals were anesthetized and instrumented for the measurement of lung function. (a) ACh (100, 500, and 2,000 μg/kg intravenously) was given and the maximum increase in overflow pressure was measured using a modification of the technique of Konzett and Rössler (20). Three doses of ACh were administered in a randomized fashion to each animal. (b) ACh (500 μg/kg intravenously) was given 5, 10, 15, 30, and 45 minutes after the first dose of ACh, and the maximum increase overflow pressure was measured. Data points and bars represent the mean ± SEM of three and four determinations for the dose-dependence and reproducibility study, respectively.