Antecedent Structural Changes
In 1872 Ord took up the novel standpoint that there was an inborn tendency in the fibroid tissues of gouty subjects to undergo a special type of degeneration, which same might be inherited or acquired. Also that this innate peculiarity was attended by excessive formation of urate of soda in these tissues, and which subsequently gaining entry therefrom into the blood, was deposited promiscuously in the body with a predilection for relatively non-vascular structures, viz., cartilages.
As to the local inflammations typical of gout, Ord’s attitude was somewhat ambiguous. Thus he maintains, “The local inflammations do not necessarily depend upon the deposit of urate and the deposit is not a consequence of inflammation; at the same time, it is probable that excess of urate in the blood produces irritation of tissues.” Neither did he believe that the local inflammatory reactions were of necessity in every instance specific, viz., due invariably to mechanical irritation by uratic deposits, but that they might be initiated by injuries, exposure to cold, etc. Lastly, as to the migration of the disorder from place to place, he believed that for its explanation direct or reflex nervous agencies had to be invoked, for he held the opinion that the local gouty “degeneration and inflammation tend to infect the rest of the system through the blood, and to set up similar actions elsewhere through reflex nervous influence.”
We see, therefore, that for Ord gout, as Ewart observes, was “a mode of decay” or a “disease of degenerations.” “The local tissue degeneracies supply a basis for the uratic deposits and the general degenerative changes multiply the sites exposed to an infiltration from the contaminated blood; whilst reflex mechanisms step in as additional determining agents.”[4]
Reminiscent of Ord’s view is the hypothesis associated with the name of Ebstein. As the outcome of experimental study he arrived at the conclusion that the primary factor in the causation of gout was a disturbance of tissue nutrition culminating in death or necrosis of the damaged textures. The initial nutritional derangement was ascribed by him to the irritant effect of soluble neutral sodium urate. This necrotising agent, following the development of “free acid” during the process of necrosis, was transmuted into the acid urate. Subsequently this same was deposited in crystalline form in the necrosed area. He held these areas of necrosis quite as typical of gout as the uratic deposits, and postulated their combinations to be necessary for the production of a true gouty focus, claiming that he had detected such foci in cartilage, tendons, kidneys, and connective tissue.
Experimentally, Ebstein endeavoured to induce a gouty condition in fowls by ligaturing both ureters, thus thrusting upon the circulation the dammed-up uratic secretion. In other instances he administered to the same animals subcutaneous injections of neutral chromate of potassium, attributing to this substance the power of inhibiting the excretion of uric acid viâ the kidneys through its action on the renal parenchyma. Subsequently, after death he noted the incidence of uratic deposits in joints, muscles, tendon sheaths, and liver, the same being more copious in those animals subjected to chromate injections.
His conclusions were: (1) That necrosing and necrotic processes are developed in various organs as a result of some irritant. (2) That uratic deposits occur in the necrosed area resembling those met with in gouty subjects. (3) That an inflammatory reaction with small cell infiltration ensues in the vicinity of such necrotic areas.
But, in regard to these experimental investigations, they are obviously incomparable to the morbid processes that presumably occur in gout in man. Moreover, as shrewdly pointed out by Levison, experimental ligation of both ureters would certainly engender uræmia rather than anything approximating to gout.
Again, his experiments with urates and uric acid, by which he claims to have demonstrated their action as chemical irritants capable of inducing necroses in tissues, have proved fallacious. This, for the very cogent reasons pointed out by Luff, which run as follows: “Not only is there no proof that the neutral sodium urate upon which he depends for the starting of the gouty changes, ever exists in the human body, but, on the other hand, very strong evidence to show that it never can exist in the human body.”... “The neutral sodium urate is an extremely caustic and unstable compound, and is decomposed in the presence of carbonates, so that it is impossible for it to exist in the blood. The first factor upon which Ebstein relied for his theory for the causation of gout therefore disappears.”
Again, Ebstein’s fundamental proposition that in gout uric acid was produced in many tissues not normally concerned in its production, was ruled out by Horbaczewski’s establishing the fact that in health uric acid is a by-product of the metabolism of almost all tissues. Lastly, the strong toxic properties accredited by him to solutions of the urates was disproved by Pfeiffer’s experiments. This observer showed that urates, in such degrees of concentration as may exist in the human body, are incapable, when injected into the tissues, of inducing necrosis.