Studies on the Coagulation of Chicken Blood. XIII. Dietary Factors Limiting the pi-Factor Level: Identification and Function of Phytoene.

Abstract

Further studies of the fat soluble factors correcting diet-induced [pi]-factor deficiency in chickens are reported. Phytoene was identified as the active factor in corn oil and cod liver oil. The minimum requirement for complete correction of severe deficiencies was 2 x 10-4 [mu]g/g of body weight when given orally for 3 days in succession. After intravenous injections of phytoene a lag period of about 10 min was observed. A rapid increase in [pi] -factor concentration ensued, reaching the maximum level about 35 minutes after the injection. Unidentified, active factors present in lard, chicken liver fat, and whale liver oil, appear to be metabolically related to phytoene. Phytoene may be the precursor of the lard factor. Both seem to be precursors of two unidentified factors in chicken liver fat. One of the latter and the whale liver oil factor are probably identical and possibly the ultimate metabolite responsible for the observed effect, presumably a stimulation of [pi]-factor biosynthesis.