August 26, 1921] 



SCIENCE 



177 



Vitamines in milk: (By title.) H. Steenbock, 

 Maeiana T. Sell and E. M. Nelson. The writers 

 have been able to substantiate Osborne and Men- 

 del's findings that at least 15 c.c. of milk are re- 

 quired daily to cover a young rat 's requirements for 

 the water soluble vitamine. Generally speaking, milk 

 can not then be considered a good source of either 

 the water soluble vitamine or the antiscorbutic 

 vitamine, as our previous investigations and those 

 of others have already shown. This conclusion is 

 emphasized by the fact that it has now been found 

 that approximately 2 c.c. of mUk are necessary 

 to furnish a sufficiency of the fat soluble vitamine, 

 which shows that milk fully equals in value, with 

 one exception, our best known sources of this 

 dietary constituent. This figure can not be taken 

 as absolute, however, for even under practical farm 

 conditions a many fold variation in fat soluble 

 vitamine content easily obtains as the ration of the 

 cow changes. Sudden variations in vitamine con- 

 tent are probably in large part prevented by drain- 

 age of the storage reservoirs of the animal. Liver 

 tissue for one has been found to depreciate in fat 

 soluble vitamine content on a fat soluble vitamine 

 poor diet. Yet in the aggregate even this effect 

 can not be very prolonged. 



Further experiments on the isolation of the anti- 

 neuritic vitamuie: Atherton SEroELL. In a pre- 

 vious paper (Public Health Reports, April 1, 1921) 

 it was shown by control tests on pigeons that the 

 precipitate obtained by addition of ammoniacal 

 silver nitrate to a purified vitamine extract made 

 from yeast "activated" fuller's earth is highly 

 antineuritio. This vitamine silver complex is 

 amorphous and its conversion to a crystalline con- 

 dition has not been effected. Attention has, there- 

 fore, been directed towards the preparation of 

 crystalline derivatives of the active constituent of 

 the compound. Among those which have been 

 obtained are the picrate, nitrate and what ap- 

 pears to be the free base. Of these, the picrate 

 does not give a constant melting point and yields 

 picric acid by ether extraction. The nitrate melts 

 with decomposition at 146°. The base is very 

 slightly soluble in strong alcohol but so soluble 

 in water that a viscous pellicle is usually obtained 

 on slow evaporation of the aqueous solution. The 

 physiological testing of these products has not 

 been completed. 



The occurrence in the anvmal organism of two 

 types of lipases: Victor E. Levine and Francis 

 J. McDoNouGH. Lipase was found in all the 



organs of the pig that have thus far been ex- 

 amined. By the action of bile or bile salts (sodium 

 glycoeholate and sodium taurocholate), the lipo- 

 lytic enzyme may be differentiated into two types: 

 a-lipase and /3-lipase. The former is observed 

 only in the pancreas or in its secretions. Its 

 activity is accelerated by bile or bile salts and by 

 heated blood serum. The latter is found in all 

 the other tissues tested. Its activity is also ac- 

 celerated by serum, but is markedly inhibited by 

 bile or bile salts. The contrasting effect of bile 

 salts therefore serves to distinguish the exo-lipase 

 of the pancreas from the endo-lipase of all other 

 organs. In the light of these experimental results 

 Cohnheim's contention, that no difference exists 

 between an exo-enzyme and its corresponding endo- 

 enzyme, is untenable. In view of the similarity 

 in the action of serum upon a-lipase and upon ^- 

 lipase it is probable that the two types possess 

 the same groupings or chemical nuclei in their 

 molecular structure. The dissimilarity in the ef- 

 fect of bile salts may be the result of tautomeric 

 modification, or may indicate a difference in 

 stereoisomeric configuration or a variation in the 

 side chains or substituents in the major group- 

 ings of the enzyme molecule. 



The distribution of lipolytic activity in the 

 hidney: Victor E. Levine and Salver A. Gia- 

 NELLI. Studies were made of the lipolytic ac- 

 tivity of the kidney of the rabbit, dog, sheep, pig 

 and cow. The source of enzyme was a chloroform- 

 water extract of the anatomical regions of the kid- 

 ney, cortex, upper medulla and lower medulla 

 (papillary portion). Ethyl acetate, ethyl buty- 

 rate, methyl salicylate, olive oil and castor oil 

 served as zymolytes or substrates. Quantities of 

 extract equivalent to 80 mgs. of tissue were em- 

 ployed, and the lipolytic activity determined by 

 titration, in the presence of phenolphthalein, with 

 N/25 or N/50 sodium hydroxide. When olive oil 

 or castor oil was used, titrations were made after 

 the addition of alcohol. The two kidneys in the 

 same animal always show a distinct variation in 

 lipolytic activity. The greatest lipolysis is regu- 

 larly observed in the cortex, the least in the 

 lower portion of the medulla (papillary region). 

 The relative extent of lipolytic activity corre- 

 sponds to the relative distribution of fat in the 

 kidney as recently reported by Christianna Smith 

 (Amer. Jour. Anat., 1920, 27, 69). This distribu- 

 tion in accordance with the anatomical divisions 

 of the kidney explains the preponderating occur- 

 rence of fat in the cortex under normal conditions 



