EFFECTS OF POSTERIOR PITUITARY EXTRACTS ON BASAL METABOLISM

Abstract
In 64 experiments on 20 rats the changes in O consumption, CO2 production and R.Q. after the subcutaneous injection of pituitrin, pitressin, and pitocin, were determined by Hal-dane''s method. The decrease of the metabolic rate by pituitrin is due to pitressin and occurs despite the effect of pitocin, since pitressin markedly diminishes the metabolic rate, while pitocin increases it slightly, but definitely. Such opposing actions may explain some of the inconsistencies in the literature since the different preparations used by various observers may have contained varying amounts of the oxytocic and pressor principles. Moreover, some of the previous workers injected pituitrin peripherally in doses too small to produce definite changes, since in the present experiments effects on metabolic rate were observed only with large doses.