Carbohydrate Metabolism in Riboflavin-Deficient Dogs

Abstract

Four groups of young dogs were fed riboflavin-deficient basal diets of varying compositions, essentially high protein, high carbohydrate or high fat. When the collapse syndrome occurred, some were treated with desoxycorticosterone acetate (DCA) and some with riboflavin. Excessive amts. of pantothenic acid were given riboflavin-deficient and control dogs in one expt. and no pantothenic acid was allowed others of the riboflavin-deficient animals. Both chronic and acute riboflavin deficiencies were studied. On the high fat diet a gradual decrease in the level of all the blood constituents was produced with collapse without signs of dehydration. On the other diets the hemoglobin concn., red and white cells, serum protein and nonprotein N decreased gradually, but a few days before collapse suddenly rose to high levels. Blood glucose and chloride levels fell at the same time and continued to fall up to and in. collapse. On admn. of riboflavin the hemoconcentration was relieved but glucose and chloride levels were raised. DCA relieved the hemoconcentration only temporarily. The carbohydrate tolerance of all the riboflavin-deficient dogs was lowered, that of those on the high fat diet more severely than the other. Almost complete disappearance of eosinophils, maintenance or increase in total leukocytes, decrease in lymphocytes and corresponding increase in neutrophils characterized the blood picture at or preceding collapse. A collapse syndrome involving rapid and irregular heart beat, extremely low blood sugar, low body temp., coma and convulsions terminated the deficiency in nearly all cases. Hypertrophied and hemorrhagic or soft adrenals, spleens smaller than normal, fatty livers with almost no glycogen and greying of hair characterized the deficiency. The composition of the basal diet had no consistent effect on any of these changes.