THE PITUITARY BODY 



is not good evidence, that the diuresis inhibition in mammals 

 is due to an increased reabsorption of water. Likewise, in 

 mammals glomerular filtration appears not to be affected. 

 Burgess, Harvey, and Marshall (1933) determined the rate 

 of glomerular filtration and water reabsorption in different 

 classes of animals by injecting non-metaboHzed sugars like 

 xylose and sucrose. They found that posterior-lobe extract 

 did not affect glomerular filtration but did markedly increase 

 the rate of reabsorption of water in the dog and in man. In 

 the fowl two effects occurred: increased reabsorption of water 

 and diminished glomerular filtration. In the reptile {Alli- 

 gator mississippiensis) the only effect of the extract was a 

 diminished glomerular filtration. No diuresis inhibition was 

 observed in the amphibian'^ {Rana catesbiana) and in the fish 

 {Ameriurus nebulosus). Correlating these observations with 

 the anatomy of the kidney in the different classes of animals 

 used. Burgess, Harvey, and Marshall concluded that pos- 

 terior-lobe extract causes an increased rate of water reab- 

 sorption because of its effect on Henle's loop which is found 

 in the kidney of the mammal and bird but not in that of 

 animals of other classes. Their conclusion is in good agree- 

 ment with the physiological-anatomical studies of Gersh 



(1934)-' 



The reabsorption of water by the kidney under the influ- 

 ence of posterior-lobe extract does not proceed beyond — and 

 usually does not reach — the kidney's maximum concentrat- 

 ing power (e.g., urine containing ca. 0.3 M or i per cent 

 chloride). Conversely, diuresis provoked by the administra- 

 tion of solutions of salt or urea may be little affected by the 

 coincident administration of posterior-lobe extract (Brunn, 



7 See also Noguchi (1926); Tangl and Hazay (1927); and Namba (1932). 



* Other studies, principally in man, indicate that increased reabsorption of 

 water without much change in the rate of glomerular filtration is the chief cause of 

 the diuresis-inhibiting effect (Poulsson, 1930). Iversen and others (1933-34) be- 

 lieved that filtration also was diminished. It is difficult to evaluate the experiments 

 of Hauptfeld (1934). 



