THE ACTION OF THE PREPARATIONS FROM THE POSTERIOR LOBE OF THE PITUITARY GLAND UPON THE IMBIBITION OF WATER BY FROGS

Abstract

Pitocin and pitres-sin were studied in parallel with the corresponding laboratory preparations, postlobin-O and postlobin-V, obtained by an original method of separation. All 4 gave rise to an increase in weight when injected into the dorsal lymph sac of Rana pipiens and if administered along with 5 ml. of saline, the elimination of saline was delayed. The 2 oxytocic preparations were equally effective as were the 2 pressor preparations though to a lesser extent being approximately 1/4 as effective. Pituitrin was as effective as pitocin and postlobin-O; a strong melanophore preparation was without action. An unknown constituent does not seem to be involved.