Paul L. Day

Cataract and Other Ocular Changes in Vitamin G Deficiency

Experiments recorded in this paper indicate that a diet deficient in vitamin G causes cataract in rats in from two to three months. From the Departments of Physiological Chemistry and Anatomy, School of Medicine, University of Arkansas, and the Department of Ophthalmology, School of Medicine, University of Iowa.

Effect of Various Doses of Total Body X-Irradiation on Total Amount of Deoxyribonuclease II in Rat Spleen.

Summary The increases in activity of spleen DNase II following a series of different doses of total-body x-irradiation 24 hours after treatment have been measured. These increases have been correlated with the change in spleen weights associated with the irradiation.

The metabolic conversion of folic acid and citrovorum factor to a diazotizable amine.

Abstract Incubation of pteroylglutamic acid (PGA) (folic acid) with liver slices leads to the formation of a diazotizable amine; this reaction is inhibited by aminopterin. Incubation of synthetic citrovorum factor (CF) with liver homogenate results in amine formation, and the reaction is not inhibited by aminopterin. The data indicate that PGA is converted to CF which in turn is cleaved to a diazotizable amine. This cleavage reaction is strongly inhibited by ascorbic acid. The urinary excretion of diazotizable amine by rats is proportional to the dose of injected PGA or CF. The magnitude of the amine excretion suggests that cleavage to a diazotizable amine is a pathway of importance for the metabolic disposal of CF.

Effect of Total Body X-Irradiation on Desoxyribonuclease Activity of Rateen.∗

Summary 1. The “acid-active” DNAase of rat spleen has been found to increase markedly after 500 r of total body x-irradiation. 2. Such a change is not apparent in the “neutral” enzyme of liver or spleen. 3. The maximum in activity of th elevated DNAase occurs 24-48 hours post-irradiation. 4. Maximal response is elicited at a dose of 200 r.

Procarcinogenic effect of vitamin B12 on p-dimethylaminoazobenzene-fed rats.

Summary Vitamin B12 has been found to enhance markedly the carcinogenic effect of p-dimethylaminoazobenzene in rats receiving a methionine-deficient diet. However, a control group of rats receiving this diet without p-dimethylaminoazobenzene showed no hepatic tumors.

Blood sugar levels and cataract in alloxan-treated, galactose-fed and xylose-fed weanling rats.

Summary Cataract was produced experimentally in weanling littermate rats by (1) alloxan treatment, (2) galactose feeding, and (3) xylose feeding. All groups showed greatly elevated blood sugar levels as compared with untreated controls receiving glucose. Cataract was exhibited by all of the xylose- and galac-tose-fed rats, and by nearly all of the alloxan-treated rats. However, the development of cataract was much slower in the alloxan-treated than in the other groups. It is concluded that not only the level of blood sugar, but also the specific configuration of the sugar concerned is a factor in its cataractogenic action.

Xylose as a Cataractogenic Agent.

Summary Young rats given a diet containing 35% xylose developed cataractous changes within approximately the same length of time as did litter mates receiving a similar diet containing 35% galactose. Controls receiving glucose showed no lenticular changes. It is suggested that the cataractogenic activity of sugars may be dependent upon certain molecular configurations.

Metabolic Interrelationships of Vitamins E and B6.

Summary Rats deficient in both vit. E and B6 exhibited an increased excretion of allantoin and creatine and supplementation of the diet with either of these vitamins prevented this increase. Vit. B6 deficiency resulted in a decreased rate of growth and in the excretion of xanthurenic acid following tryptophan administration. Vit. E did not influence growth or xanthurenic acid excretion.

Vitamin B6 and Erythropoiesis in the Rat.

Summary 1) Severe vit. B6 deficiency in the rat resulted in an increased red cell count and in a reduction in hemoglobin, mean cell volume, and mean cell hemoglobin. The most striking effect was the reduction in mean cell hemoglobin in the deficient rats. The B6-deficient rats exhibited lymphopenia and granulocytosis. 2) The data show that the rat must be added to the list of animals requiring vit. B6 for normal hematopoiesis.

Effects of a Combined Deficiency of Vitamins E and B6 on Blood Picture of Rat.

Summary Sprague-Dawley rats deficient in both vit. E and B6 exhibited a greatly increased peripheral neutrophil count. Supplementation of the diet with either of these vitamins prevented this increase. The B6-deficient rats exhibited a slight lymphopenia which was not affected by vit. E. None of the animals developed anemia.