[The effect of symphathicotropic substances on liver microsomes in vivo and in vitro]

Ephedrine and propranolol shorten hexobarbital sleeping time and increase amidopyrine-N-demethylation activity. Pholedrine only scarcely acts on these parameters, dihydroergotamine is effective. In vitro, ephedrine, pholedrine, propranolol and above all dihydroergotamine proved to be inhibitors of amidopyrine-N-demethylation. Noradrenaline, cAMP and dibutyryli cAMP were ineffective. An influence of the sympathetic nervous system on biotransformation activity cannot be recognized.