THE PITUITARY BODY 



the pituitary body, none withstands chemical manipulation 

 better than the chromatosome-dispersing hormone. The hor- 

 mone is soluble in dilute aqueous solutions of acid or alkali 

 and in certain organic solvents such as methanol and ethanol. 

 Like the hormones of the pars neuralis, it is not destroyed by 

 boiling in acidified water. However, it is remarkable that 

 the hormone not only survives treatment by, or boiling in, 

 fairly strong alkaline solutions, e.g., N/io, but also that its 

 effects appear to be much more pronounced after this treat- 

 ment, as was first shown by Hogben and Gordon. Bottger 

 (1937) believed that after alkali has acted upon the hormone, 

 the latter is metabolized more slowly, as shown by changes 

 in the intensity and duration of its effects. According to 

 Stehle (1936), the hormone is altered qualitatively, i.e., the 

 initial effect is less intense but the duration of action is much 

 longer. The degree of potentiation of the action of the hor- 

 mone as a result of treatment by alkali has not been exactly 

 defined. Stehle is of the opinion that it is much greater than 

 Jores' estimate of 200-300 per cent. According to Abramo- 

 vitz (1937), the chromatosome-dispersing effect of the pitui- 

 tary o{ Fundulus is increased about twenty-five fold by boil- 

 ing in N/io NaOH. 



It is probable that the same hormone causes dispersion of 

 both melanosomes and erythrosomes. This view has recently 

 been supported by Bottger (1937). New methods of purifying 

 chromatosome-dispersing hormone have been described by 

 Stehle (1936) and Bottger (1937). Stehle's product was about 

 twenty-five times as active as International Standard Powder 

 (posterior-lobe). 



SUMMARY 



The pituitary body or homologues of its divisions may be 

 of great importance in the regulation of the distribution of 

 pigment-granules in chromatophores of cold-blooded animals. 

 Almost all the detailed studies are concerned with melano- 

 phores (fishes, amphibia, reptiles) and erythrophores (fishes). 



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