PT - JOURNAL ARTICLE AU - ARTHUR A. HANCOCK AU - ANDRE L. DELEAN AU - ROBERT J. LEFKOWITZ TI - Quantitative Resolution of <em>Beta</em>-Adrenergic Receptor Subtypes by Selective Ligand Binding: Application of a Computerized Model Fitting Technique DP - 1979 Jul 01 TA - Molecular Pharmacology PG - 1--9 VI - 16 IP - 1 4099 - http://molpharm.aspetjournals.org/content/16/1/1.short 4100 - http://molpharm.aspetjournals.org/content/16/1/1.full SO - Mol Pharmacol1979 Jul 01; 16 AB - Frog myocardium appears to possess both beta1 and beta2 receptors, based on the potency order of several adrenergic agonists to compete for [3H]dihydroalprenolo1 binding. Selective beta blocking agents are able to distinguish two receptor subtypes in frog myocardium, but only one site in rat ventricle. Computer modeling using a PDP 11/45 indicates that all rat beta receptors are beta1, whereas only 15%-25% of frog ventricular beta receptors are of the beta1 subtype. Computerized curve fitting can provide a more accurate estimate of receptor parameters than currently available graphical methods of analysis. ACKNOWLEDGMENTS A.D.L. wishes to thank Frank Starmer and Bruce Wright of the Department of Clinical Epidemiology, Duke University, for generously providing access and guidance to the PDP 11/45 computer. The numerical analyses underlying the computer program were performed by A.D.L. at the NIH, NICHD, ERRB, in collaboration with P. J. Munson and D. Rodbard.