EXPERIMENTS UPON THE RELATION BETWEEN THE PITUITARY GLAND AND WATER DIURESIS

Abstract

The theory of a control over urine vol. by the post, lobe of the pituitary gland was investigated by the search for an antidiuretic principle of pituitary origin in the blood, cerebrospinal fluid and urine of various animals. The investigation was confined to changes in urine vol. produced by variations in water intake: water diuresis and the oliguria following dehydration. An adsorption-elution method was developed which permitted the separation of antidiuretic substance from other constituents of cerebrospinal fluid and urine. The substance thus separated was assayed by the rat method of Burn and by intraven. inj. into diuretic rabbits. All of the body fluids examined were found to contain small amts. of an antidiuretic substance but it was concluded that this substance did not originate in the post. lobe of the pituitary gland since its presence was unaffected by pituitarectomy (assays on dogs'' cerebrospinal fluid and cats'' urine) and since it was unlike commercial pituitrin preps. in respect to its stability (assays on rats'' urine). With a partial exception in the case of rats, the amt. of the substance which could be recovered from urine bore no relation to the degree of hydration of the animal so it was impossible to ascribe it physiological importance in the regulation of urine vol. Studies on cerebrospinal fluid are not sufficiently complete to confirm or deny a physiological r61e for the substance. The finding that pituitarectomized cats and rats respond to water adm. and water withdrawal by changes in urine vol. analogous to those displayed by normal animals casts additional doubt on the importance of the post. lobe of the pituitary gland in the regulation of urine vol.