Absence of Appreciable L. casei Factor Effect in Anti-Pernicious Anemia Liver Extract

Abstract

The absence of considerable quantities of “free” L. casei factor from concentrated anti-pernicious-anemia liver extracts 1 is in contrast with the effect of the “liver” form of L. casei factor in producing remission of pernicious anemia. 2 - 4 The possibility remained that “free” L. casei factor could be liberated in vitro or in vivo from the maturation factor which is present in such liver extracts.

In the present investigation, concentrated parenteral liver extract, 15 U.S.P. units per cc, was incubated with dried chicken pancreas, which contained “vitamin B_c conjugase.” The content of “free” L. casei factor after incubation was found to be 1.0 μg per cc by L. casei assay and 0.8 μg per cc by S. lactis R assay, against synthetic “liver” L. casei factor standard.

The effect of various samples of the same type of liver extract on chicks deficient in L. casei factor was then measured. Day-old New Hampshire Red chicks were placed on the diets. Ten chicks were used in each group. The basal diet had the following composition: glucose (cerelose) 58.5 g, purified casein (Labco) 20 g, gelatin 8 g, calcium gluconate 5 g, cystine 0.4 g, choline chloride 0.2 g, inositol 0.1 g, bone ash 2 g, NaCl 0.6 g, KH₄, PO₄ 0.45 g, K₂HPO₄ 0.6 g, MgSO₄ 0.25 g, MnSO₄,4H₂O 0.05 g, ferric citrate 0.05 g, CuSO₄,5H₂O 2 mg, A1₂(SO₄)₃,18H₂O 1.6 mg, zinc acetate 1.4 mg, KI 0.6 mg, cobalt chloride 0.4 mg, nickel chloride 0.2 mg, calcium pantothenate 5 mg, niacinamide 5 mg, riboflavin 1 mg, pyridoxine HC1 1 mg, thiamine HC1 1 mg, p-aminobenzoic acid 1 mg, 1-acetoxy-2 methyl-4 naphthyl sodium phosphate 0.5 mg, (dl) biotin .04 mg∗ to which were added vitamin A 1500 U.S.P. units, vitamin D 200 A.O.A.C. units, mixed tocopherols 34 mg, dissolved in corn oil (Mazola) to a total of 3 g. Table I illustrates the results of a typical experiment in which concentrated parenteral liver extract was injected into chicks at a rate which corresponded to approximately 0.4 U.S.P. unit of maturation factor per day.