Purin Metabolism in Chronic Alcoholism and Plumbism
Quoting from Mallory’s contribution, we note that Pollak investigated the purin metabolism in a series of cases of chronic alcoholism. In five of the examples a marked derangement of purin metabolism was noted and manifested, “partly in retention, and partly in delayed excretion, or a combination of the two.” Having observed these variations in cases of what he considered were non-gouty alcoholics, Pollak felt justified in attaching but limited diagnostic import to the results of the examination of uric acid metabolism in gout, this though he realises the importance of alcoholic excess as a cause of disturbed purin metabolism.
Mallory’s observations, too, on uric acid excretion in gout complicated by lead poisoning are highly interesting. In two cases of this nature he noted that the percentage of uric acid nitrogen excreted was relatively small—in this respect in full accord with previous observations of Brugsch and Schittenhelm on a gouty patient with a history of plumbism, with this reservation, that in the latter observers’ example there were indications of early renal disease, while in Mallory’s two cases such was absent, the urine being normal, and likewise the blood pressure.
Again, Pollak in a case of lead gout noted an extremely low endogenous average, viz., a daily average endogenous excretion of 0·06 gram uric acid in a period of five days. Eschemburg, quoted by Pollak, has recorded an instance of gout with plumbism in which the excretion fell as low as 0·02-0·04 grams. It may be noted that Pollak’s was the victim also of incipient renal disease.
Reverting to Mallory’s conclusions, this observer’s studies of examples of gout with lead poisoning seem to indicate that “these cases differ from normal persons to a greater degree than do other cases of gout.” It may, he thinks, be affirmed that the subjects of gout and plumbism, as a rule, show “some or all of the following characteristics in a much more marked degree than do cases unassociated with lead”:—
(1) Slight fluctuation in the endogenous excretion.
(2) Low endogenous average.
(3) Small percentage of exogenous purin nitrogen excreted as uric acid nitrogen.
To sum up, then, we see that poisons, other than those responsible for gout, may engender obliquities of general metabolism, with disturbances of purin assimilation and output, viz., lead, alcohol, and the causa causans of rheumatoid arthritis. Also, in respect of lead poisoning and alcoholism, further affinities with gout are discernible in that, like the latter disorder, they tend in their later stages to be associated with arterio-sclerosis and renal inadequacy.