ALA Dehydrase Research Articles

Urinary excretion of 5-aminolevulinate and porphobilinogen in diabetes.

In 56 diabetics, 24-h urinary excretion of 5-aminolevulinic acid (ALA) and porphobilinogen (PBG) was determined by the method of Mauzerall and Granick. There was no significant difference between the mean values obtained for these patients, as compared with the control group (40 subjects). No correlation was also found between ALA and PBG excretion, as calculated against body weight, duration of diabetes and kind of treatment. There was a high degree of correlation between the excretion of ALA and diuresis (r xz =+0.75), as well as glycosuria (r yz =+0.66), whereas the correlation between the excretion of PBG and diuresis, as well as glycosuria, was low. In uncontrolled diabetes with ketonuria, (10 subjects), a significant increase in the excretion of ALA, with unchanged excretion of PBG, was observed. — In healthy subjects, there was no significant correlation between the ALA and PBG excretion and diuresis. The determination of the urinary ALA and PBG excretion during water diuresis and during osmotic diuresis induced by intravenous infusion of hypertonic glucose solution in healthy subjects, disclosed evidence testifying against the effect of glucose on ALA reabsorption in the renal tubules. — The present findings are interpreted by the authors as resulting from enhanced ALA synthetase activity and impaired ALA dehydrase activity in uncontrolled diabetes; these disturbances being related to the defective intracellular glucose metabolism and reduced ATP production.

Effect of glycine loading on delta-aminolevulinic acid (ALA) and porphobilinogen (PBG) excretion during starvation

Studies in 18 nonporphyric subjects demonstrate that starvation from two to 15 days may induce an increase in hepatic ALA synthetase activity, resulting in increasing quantities of urinary ALA excretion which, however, remain within the normal range. The ingestion of glycine during starvation causes a rise above the upper limits of normal in urinary ALA excretion. Starvation does not affect urinary PBG output nor does the ingestion of glycine produce a response. Measurements of ALA dehydrase activity in red blood cells during starvation showed no consistent decrease. Refeeding with a regular diet caused a prompt reduction of urinary ALA excretion and abolished the positive response to glycine.

ERYTHROPOIESIS AND DELTA-AMINOLEVULINIC ACID DEHYDRASE ACTIVITY.

The delta-aminolevulinic acid dehydrase activity of rat and mouse spleen, bone marrow and liver fractions and homo-genates was determined. Spleen ALA dehydrase specific activity of normal, polycy-themic, and anemic rats was found to decrease exponentially with the increase in hematocrit of the animal. However, sheep plasma erythropoietin, incubated with the tissue fractions and homogenates, did not directly produce an increase in enzyme activity over that of the controls.

ALA dehydrase activity in liver and kidney of rats and rabbits with experimental porphyria

ALA dehydrase activity in liver and kidney of rats and rabbits with experimental porphyria