Figure 4. Effects of 3% halothane (0.9 mM) and 4% isoflurane (0.9 mM) on the smooth muscle content of cyclic adenosine monophosphate (cAMP) induced by 10^-7M isoproterenol or 10^-6.5 M forskolin (n = 6 each). Isoproterenol and forskolin increased cAMP levels in the smooth muscle. Isoproterenol-induced, but not forskolin-induced, increases in cAMP content were attenuated by halothane and isoflurane. *Significant differences from the respective control value. [dagger] Significant differences from no anesthetics. P < 0.05, and n = 6 each.