Effects of cholinomimetic agents on pentobarbital anesthesia in mice.

We evaluated the effects of physostigmine, choline chloride, and neostigmine on pentobarbital anesthesia in mice, both when given before and after the administration of pentobarbital. Neostigmine and choline chloride had no effects. Physostigmine shortened the onset of pentobarbital anesthesia when given before pentobarbital but had no effects on the duration of anesthesia. However, when given after pentobarbital it shortened the duration of pentobarbital anesthesia. It seems unlikely that the above effects of physostigmine are dependent on the cholinergic system in the nervous system since neostigmine and choline chloride were without action. However, they may be due to the effects of physostigmine on the blood brain barrier permeability to pentobarbital.