Studies on the method of creatine determination and its practice. II. the conversion mechanism of creatine to creatinine

Niiyama, Y.

Osaka City Medical Journal 10: 575-584

1961


ISSN/ISBN: 0030-6096
PMID: 14479757
Document Number: 3179
In vitro studies were made of influences of solvent pH upon the rate, of conversion from creatine to creatinine. In order to determine the rate or character of such conversion accurately, developed creatinine and residual creatine were simultaneously estimated a certain time, the former by the Hg-dithizonate method and the latter by the method with an application of naphthol-diacetyl reaction. The results obtained were as follows 1) In acidic reaction creatine converts irreversibly to creatinine and with the first order reaction pattern. The rate constants, k, 4, 1, and 0.1 N HCl solutions at 38°C were 0.21525, 0.02710 and 0.00798, respectively. On the other hand, in weaker acidic regions, around pH 3, the creatine conversion was markedly accelerated. Thus it is suggested that the dehydration of creatine is carried out in two different mechanisms. 2) In alkaline solution reversible changes between creatine and creatinine were observed, establishing a stationary' state in certain hours. The creatine-creatikne ratio in the stationary state established on condition of 1 N NaOH and 38°C was about 1.98. 3) Under neutral conditions a slow and irreversible conversion from creatine to creatinine was confirmed. The rate constant at 38°C was 0:00053, from which value it was calculated that 1.27 per cent of creatine was converted to creatinine daily. This creatinine formation rate was considerably lower than that of in vivo, which was 2 per cent.

Document emailed within 1 workday
Secure & encrypted payments

Studies on the method of creatine determination and its practice. II. the conversion mechanism of creatine to creatinine