OCCURRENCE OF THE VITAMINS A 679 



ova'^ discovered that the liver oils from certain Russian fresh-water fishes 

 gave a stronger response at 690 myu with an antimony trichloride reagent 

 than at the conventional 620 m^t position. ^Vhen the non-saponifiable frac- 

 tions of liver oils of fresh-watei- fishes were dissolved in alcohol, the maxi- 

 mum absorption in the ultraviolet area was found at 340-350 m^.'-^ A new 

 band at 280-285 mju was also noted. The high ratios between extinction 

 values at (i93 m^i and ()20 m/x in antimony trichloride tests were always as- 

 sociated with the liver oils of fresh-water fishes in which the maximum ab- 

 sorption of the untreated product was 340-345 m/i. Edisbury et al}'^ found 

 that the goldfish eye preparations also had absoiption maxima at 350 and 

 288 m^. 



In a further study of the Carr-Price reaction with the liver oils of fresh- 

 water fishes, Gillam et alJ^ reported that the 693 : 620 m^u ratio was usually 

 in the neighborhood of 2: 1, contrasted with a ratio of 0.15: 1 for the liver 

 oils of marine fishes. Morton" reports that, although the proportions of 

 Ai and A) in the liver oils of fresh-water fishes are highly variable, certain 

 statements can be made. For example, £^693 jn^:£'620m/x is highest between 

 2 and 3 in the carnivorous fishes such as the pike {Esox lucius), the pike 

 perch or sander {Lucioperca sandra), the fresh-water perch (Perca fluviati- 

 lis), and the wels, or European catfish (Silurus giants). In the case of 

 omnivorous fishes, the ratio was found to be considerably lower, which in- 

 dicates a much lower proportion of vitamin A2 and considerable amounts 

 of vitamin Ai. Fishes which are included in this category are the bream 

 {Abramis hrama), the carp (Cyprinus carpio), and the tench {Tinea tinea). 

 The liver oils of migratory fishes also showed the lower E'easmM '• E&2Qm^ ratio. 

 This was the case with the North Atlantic salmon {Salmo solar), the 

 sturgeon (Acipenser stuno), the eel (Anguilla vulgaris), and the broAvn brook 

 trout (Salmo fario) and rainbow trout (Salmo irideus). It was found that 

 the ratio of vitamins A2 : Ai is fairly constant in any given species; it is also 

 independent of sex and age. It shows little seasonal variation and is not re- 

 lated to the geographic source of the fishes." The ratio of •E'693mM'^62omM 

 is usually highest in the liver oils, pyloric caeca, and other absorbing surfaces 

 of the gut. However, according to Morton,'^' Lederer found that, in carp, a 

 ratio of 2.3:3.5 obtained in the retina, as against 0.5:0.9 in the liver. The 

 vitamin A2 content of the pike perch is given in Table 3, which follows on 

 page 680. 



■* E. Lederer and V. A. Rosanova, Biokhimiija, 2, 293-303 (1937); Chem. Ahsi., SI, 

 5105 (1937). Cited by R. A. Morton, The Application of Absorption Spectra to the Study 

 of Vitamins, Hormones, and Coenzymes, 2nd ed., .Jarrell, Ash, Boston, 1942, p. 76. 



'= E. Lederer, V. Rosanova, A. E. Gillam, and L M. Heilbron, Nature, HO, 233 (1937). 



" A. E. Gillam, L M. Heilbron, W. E. .Jones, E. Lederer, and V. Rosanova, Biochem. 

 J., 32, 405-416 (1938). 



■'^ R. k. Morton, The Application of Absorption Spectra to the Study of Vitamins, Hor- 

 mones, and Coenzymes, 2nd ed., Jarrell, Ash, Boston, 1942. 



