Passage of gallamine from blood into the liquor space in man and in dog.

1. Patients receiving an intravenous injection of 2-3.8 mg/kg gallamine showed gallamine-like activity in their lumbar c.s.f. collected 15 and 70-100 min after the injection. The activity assayed on acetylcholine contractions of frog rectus muscle was equivalent to between 0.1 and 0.75 mug/ml gallamine.2. In anaesthetized dogs an intravenous injection as well as an intravenous infusion of gallamine led to the appearance of gallamine-like activity in the cisternal c.s.f. and, on perfusion of the cerebral ventricles, in the effluent collected from the cisterna magna.3. After an intravenous injection of 1 mg/kg the activity in the cisternal c.s.f. corresponded to between 0.2 and 1 mug/ml and in the effluent to between 130 and 175 ng/min during the first 15 min perfusion and then declined.4. On intravenous infusion of gallamine at a rate of 10 (mug/kg)/min for 2 h the cisternal c.s.f. showed a uniform gallamine-like activity corresponding to between 0.4 and 0.67 mug/ml during the infusion. In the cisternal effluent the gallamine-like activity rose initially to between 20 and 90 ng/min but declined before the infusion was ended.5. The intravenous injection of gallamine caused respiratory paralysis but did not affect arterial blood pressure; its intravenous infusion caused no respiratory paralysis and did not affect arterial blood pressure.