Some considerations on urinary glucaric acid, especially on the relationship between glucaric acid and beta-glucuronidase activity in urine after intravenous administration of xylitol

摘要

Since these 3 or 4 years the interrelationship between glucaric acid andβ -glucuronidase in urine has been stressed in Japan; and considerably many investigators have regarded the urinary glucaric acid as an index of inhibitory agents toβ-glucuronidase in urine, the conversion rate of glucosaccharo 1 • 4, 3 •6 dilactone into glucaric acid as an index to distinguish bladder cancer from others, and the programmed increase of urinary glucaric acid as an excellent therapeutic method of bladder cancer. To confirm these findings and hypothesis, a series of clinical studies were carried out and the following results were obtained. 1. The decreased excretion of glucaric acid in urine and the decreased conversion rate of glucosaccharo 1• 4, 3• 6 dilactone into glucaric acid in urine were considered as the characteristics of bladder cancer, but were found, also, in traumatic paraplegics. So it was difficult to say these findings were specific in carcinoma of the bladder. 2. Suppression of urinary glucaric acid after glucosaccharo 1 • 4, 3 • 6 dilactone or glucuronolactone administration was observed in some of traumatic paraplegics. It was difficult to explain these findings by the present metabolic map. 3. Marked decrease of glucaric acid in urine ensued after intravenous administration of xylitol 50 g (10% 500 ml) in almost all of the cases. 4. Urinary β-glucuronidase activities were decreased in about half of cases administered glucosaccharo 1 • 4, 3• 6 dilactone and xylitol. 5. Xylitol administration resulted in the decrease of urinaryβ-glucuronidase accompanied with the decrease of urinary glucaric acid. If the above-mentioned hypothesis that glucaric acid was an index of β-glucuronidase inhibition were valid, it would be impossible to explain these findings. So it was rather rational to consider that glucaric acid and β-glucuronidase in urine were independent each other. Namely, the close interrelationship between glucaric acid and β-glucuronidase had to be considered as a fallacy.