1. Erythrocytes (RBC) from control and marginally riboflavin-deficient subjects were fractionated into nine fractions using a discrete density gradient. 2. Glutathione reductase (NAD(P)H: glutathione oxidoreductase; EC 1.6.4.2) activity and aspartate aminotransferase (EC 2.6.1.1) activity (with and without the appropriate co-enzymes) reduced glutathione, methaemoglobin, sulphaemoglobin and oxy...

1. Iron absorption was measured in weanling riboflavin-deficient (RD) rats or weight-matched (WM) controls fed on appropriate diets for 7 weeks. Concentrations of radio-Fe (59Fe) in plasma were monitored every 30 min for 4 h following intragastric administration. 2. Total Fe absorption in RD rats was significantly lower than that in WM controls, and the tissues of the stomach and small intestin...

OBJECTIVE While iron deficiency is regarded as the major cause of nutritional anaemia, changes in vitamins A, B12, C and E, folic acid and riboflavin status have also been linked to its development and control. This paper provides a systematic review of vitamin supplementation trials relating to the control of nutritional anaemia. METHODS A MEDLINE search was used to find reports of vitamin s...

Riboflavin-deficient rats have been observed to excrete considerably more kynurenic acid than normal rats after the ingestion of n-tryptophan, but only slightly more kynurenine and xanthurenic acid (1). Increased excretion of anthranilic acid has also been noted (2, 3). Although the administration of tryptophan by injection also produces an increased excretion of xanthurenic acid in riboflavin ...

Introduction ALTHOUGH the cornea normally has no blood vessels, yet, under certain conditions, new vessels freely enter the substa-nce of the cornea from the limbal plexus. To explain this invasion many theories have been advanced. In riboflavin deficiency there is corneal vascularization. Since riboflavin is part of an oxidation enzyme system, Bessey and Wolbach (1939), and Johnson and Eckardt...

who postulated that the inhibitor initially acts in a reversible competitive manner, but is then converted into fluoroaconitate which alkylates the active site of the enzyme.] Comparison of the LDSo values for fluoroacetate with the concentrations of it which inhibit hepatic respiration suggests that in neither species is the liver the critical organ. Nevertheless, it is tempting to speculate t...