Creatin and creatinin / by Edward Mellanby.

  • Edward Mellanby
Date:
[1908?]
Catalogue details

Licence: In copyright

Credit: Creatin and creatinin / by Edward Mellanby. Source: Wellcome Collection.

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    also that different groups of muscles contained different quantities of creatin. Nawrocki(4) found on the contrary that different muscles of dogs contained the same quantities of creatin, also that in dogs and frogs there was no difference in the resting and tetanised muscle. The results of Voit(5) were again different. He decided that tetanus produced a decrease of creatin in frog’s muscle, while the total quantity of creatin and creatinin was not increased. He thought that the creatin was changed during muscular contraction to another substance not identical with creatinin. Thus far, the work mentioned was performed in the sixties of last century. Of more recent workers on the direct muscle, Monari(6) stands out, and his results have up to the present been regarded with greatest favour. His results will be dealt with in greater detail later. Suffice it to say now that in fatigued dogs he got a large increase of total creatin and creatinin and at the same time a most marked conver¬ sion of creatin into creatinin. Many experimenters have attempted to elucidate the life history of creatin and creatinin in an indirect manner by finding the effect of different bodily conditions on the creatinin output in the urine. Here again results are very variable. In the urine of a dog that had run for eight hours, V oit found no increase of the creatinin. In men, however, the performance of work produced an increased creatinin excretion. Meissner (7) examined the urine of a dog which had run for five hours, and found a decrease in creatinin on the day of exercise, with a corre¬ sponding increase the next day. Taken together the exercise produced no increase of creatinin. Working on men, K. B. Hofmann (8) only got an unsteady creatinin excretion having no evident relation with the work performed. P. Grocco <9) found that the creatinin output in men was greater on the day of exercise than on the following day. Moitessier (10) found that the creatinin excreted was always larger on a day of work than on a resting day. Living on a creatinin free diet Gregor (n) decided that muscular exercise increased the creatinin out¬ put. These experimenters and many others used the Neubauer method of estimating creatinin. Making use of Jaffe’s colour test for creatinin, Folin(12) in 1901 introduced a colorimetric method for estimating this substance. The creatinin excreted he regards as of two different modes of production—one part exogenous, which is taken in with the food, and a second portion endogenous produced in the metabolic changes in the life of the cell. He regards the endogenous creatinin as being a measure of true meta-