Evaluation of methods of coenzyme activation of erythrocyte enzymes for detection of deficiency of vitamins B1, B2, and B6.

Abstract

We describe optimized, ultraviolet spectrophotometric procedures for determination of erythrocyte transketolase, glutathione reductase, and aspartate aminotransferase activity, and their activation by their respective coenzymes--thiamine pyrophosphate, flavin-adenine dinucleotide, and pyridoxal-5-phosphate--as tests for vitamin B1, B2, and B6 deficiency. With these procedures we have investigated healthy subjects on normal and vitamin-supplemented diets, and a series of (mainly) alcoholic hospital in-patients. The enzyme procedures described have good precision and can be readily carried out in the routine laboratory. Abnormal transketolase activation correlated well with clinical evidence of vitamin B1 deficiency.

Plasma homocysteine level in relation to folate and vitamin B6 status in apparently normal men

“…Erythrocyte aspartate aminotransferase activation coefficient (EAAT-AC) was determined as an index of vitamin B6 status. 13 Information on the frequency and quantity of intake of vitamin B12-containing foods was collected by interviewing the subjects. Dietary intake of vitamin B12 was calculated based on the values given in Nutritive Value of Indian Foods.…”

Thiamin deficiency and uncomplicated falciparum malaria in Laos

“…Parasite counts and haematocrit were performed daily until parasite clearance for two consecutive days and then weekly from day 7. Red cell transketolase activity assays were performed as described previously (see Krishna et al 1999) by a modification of the nicotinamide-adenine dinucleotide-dependent method with ribose-5-phosphate as the substrate (Bayoumi & Rosalki 1976) except that samples were collected into acid citrate dextrose in the earlier study and into sodium heparin in this study. We have used categories of a of <1.15, 1.15-1.24, ‡1.25 and >1.31.…”

Is disordered folate metabolism the basis for the genetic predisposition to neural tube defects?

“…Plasma vitamin A and E were measured by fluorimetry after solvent extraction (Thompson et al 1973). Status of thiamine, riboflavine and pyridoxine was assessed by activation of erythrocyte transketolase, glutathione reductase and aspartate amino transferase respectively using an LKB 2086 Reaction Rate Analyser (Bayoumi & Rosalki 1976). Serum and leukocyte ascorbic acid were measured by the method of Denson & Bowers using 2,4dinitrophenylhydrozone as colour reagent (Denson & Bowers 1961).…”