THE PURIFICATION OF THE PRESSOR AND OXYTOCIC HORMONES OF THE PITUITARY GLAND AND SOME OBSERVATIONS ON THE CHEMISTRY OF THE PRODUCTS

¹ Department of Pharmacology, McGill University, Montreal

A modification of the method of one of the authors for separating and purifying the oxytocic and pressor constituents of the posterior lobe of the pituitary gland is described. The potency of the pressor preparation was 100 times that of standard pituitary powder and that of the oxytocic preparation 125 times. The yield of pressor substance was considerably higher than that of the oxytocic.

Both preparations appear to be polypeptides containing tyrosine, cystine (or something which gives similar color reactions when the methods of Folin and Denis and of Sullivan are applied) and arginine, and probably other amino acids. They do not appear to contain histidine and the pressor substance at least does not contain phenylalanine. Tests which are not regarded as necessarily final seem to exclude the presence of glutamic acid, aspartic acid and leucine in the pressor substance. The oxytocic susbstance was not examined for these amino acids.