The distribution of vitamin A and factor A2. I

Abstract

THE present paper is the full account of work briefly reported elsewhere [Lovern et al. 1937; Edisbury et at. 1937]. The main experimental result is that fish viscera, and notably the pyloric caeca and intestines, are often very rich in vitamin A. Large deposits of vitamin in the absorptive parts of the alimentary tract make it necessary to study the possibility that vitamin A plays an essential part in food assimilation in some species. This idea is discussed in a preliminary fashion, whilst other aspects of the subject such as the physical properties of visceral oils, vitamin D content, phospholipid content, glyceride composition etc., await further study. Euler et at. [1928; 1929] showed that carotene displays vitamin A activity, in accordance with an earlier suggestion made by Steenbock. The accepted chemical structures and the known physical properties of P-carotene and vitamin A are consistent with a process 2H20 C4,H56-2C20H290H ,B-carotene 2 vitamin A first recognized in vivo by Moore [1929, 1, 2, 3]. His proofthat the administration of a diet rich in carotene results in the rat in a greatly increased accumulation of vitamin A in the liver has been confirmed and extended to fowls and rabbits [

On the Distribution of Vitamins A1 and A2

“…Low bands due to vitamins A~ and As may also be distinguished, but thdr proportions cannot be estimated in this preparation. A similar result has been obtained by Edisbury et al (1938) with a liver oil from the true perch (Perca fluviatilis).…”

“…This observation was rapidly confirmed and extended (Edisbury, Morton, Simpkins, and Lovern, 1938;Gillam, Heilbron, Jones, and Lederer, 1938;Lederer and Rathmann, 1938). The substance responsible for the antimony chloride band at 690-697 m/~ was found to possess a direct absorption band in ethanol at 345-350 m/z.…”

“…Similarly vitamin A2 possesses a sateUitic direct absorption at about 290 m# and antimony chloride maximum at 640-650 m~. Edisbury et al (1938) have reported the separation of a vitamin A2 preparation into fractions possessing direct absorptions at 350 m~ and predominantly at 285-290 mp. Lederer and Rathmann (1938), however, have failed to confirm this observation and believe both bands probably due to vitamin A2 itself.…”

“…The substances heretofore called vitamin A and retinene are found exclusively in almost all vertebrates. Ordinarily it should be un-1 In a later paper Edisbury et al (1938) refer to this substance as factor A2, apparently because "there is no evidence that its function as a vitamin extends beyond fishes." More recently GiUam et al (1938) and Lederer and Rathmann (1938) appear to base the vitamin designation for A2 principally on the demonstration of its growth-promoting activity in rats.…”

Fat-Soluble Vitamins

“…These ratios show a considerable range of variation in different tissues, such as eyes, intestines, and pyloric caeca of various species of i~sh. Edisbury, Morton, Simpkins & Lovern (2) found a high concentration of vitamin in oils prepared from tissuesof the alimentary tract especially from the pyloric caeca which they reported for the cod to be ten to twenty times greater than that of average cod-liver oil. These observations concerning the presence of vitamin _A_ in the intestinal wall have led to speculations concerning a possible r61e of the vitamin in assimilation of fat from the intestinal tract, but there are as yet no definite data supporting these hypotheses.…”