Fig. 4

Effect of propranolol, cimetidine, diphenhydramine and thioperamide on epinephrine stimulated cAMP generation in Hepa cells transfected with the mutant Ala ¹⁸⁶ -Ser ¹⁸⁷ H2-histamine receptor

Propranolol, cimetidine, and diphenhydramine dose-dependently inhibited cAMP generation stimulated by epinephrine with IC50 values of 1 ± 0.3 × 10⁻⁷ M, 5 ± 0.45 × 10⁻⁷ M, and 5 ± 1.2 × 10⁻⁸ M, respectively. Thioperamide did not alter epinephrine stimulated cAMP formation in transfected cells. Data are represented as means ± SEM, n = 4.