THE HYPERGLYCEMIC CONSTITUENT OF POSTERIOR LOBE PITUITARY EXTRACT

¹ Department of Pharmacology, McGill University, Montreal

Equal and small hyperglycemic effects may be produced by pressor and oxytocic preparations of the posterior lobe of the pituitary gland when 0.0125 unit per kilogram of the oxytocic substance and 0.25 unit per kilogram of the pressor substance are injected intravenously in dogs. For somewhat larger doses but in the same ratio this is also true. These results indicate that the oxytocic substance is responsible for the hyperglycemic action and are to be expected on the assumption that the pressor preparations are contaminated to the extent of about 5 per cent with the oxytocic substance.

The hyperglycemic action of large doses of pressor substance may be due in part to secondary (circulatory) phenomena. There is a difference between this series of events and what may properly be called the physiological action of these extracts of the posterior lobe of the pituitary gland.