Experiments to ascertain whether the loss of the weight takes place at the expense of the fat of the body or of the protoplasmic tissues, such as the muscles. Conclusions: that fresh thyroid acts en ergetically on albuminous decomposition, but that some of the efficiency is lost to the thyroid substance in the process of making tablets or in keeping it too long. The administration of the artificial prod ucts over long periods of time is, how ever, not without action on albuminous substances. Gluzinski and Lemberger (Centrelb. f. inn. Med.. -Jan. 30, '07).
Under the effect of thyroid there is an increased rapidity of combustion through out the body, while the increased urinary flow which follows its use decreases the patient's weight considerably as well. Another important effect of the thyroid gland is to hasten cell-activity. Robert Hutchinson (Brit. Med. Jour., July 16, '98).
Following conclusions deducted from a series of investigations on thyroid treat ment: 1. The loss of weight after the ingestion of thyroid is not due con clusively to loss of water and albumin, but in part, in some cases, to loss of fat. Thyroid causes, therefore, a genu ine reduction of fat. 2. So far as this is due to increase of normal tissue-change it is moderate, except in myxcedema. 3. Increase of metabolism does not occur in all persons who take thyroid. It is most marked in myxu.xlenia. 4. The proteid deficit in thyroid feeding may continue even in case of superalimentation, and is, therefore, a specific, toxieogenic effect of the substance. 5. Thyroidin shows effects on metabolism like those of the extract of the glands, but thyreotoxin and potassium iodide give no such re sults. 6. Absence of thyroid function causes not only defective growth and serious bodily and psychical degeneration, but also a distinct decrease of gaseous interchange, of heat-production, and of total metabolism. The excessive and ab normal function causes increased metab olism and emaciation. Administration of the gland in such cases is followed by in creased metabolism and improvement of symptoms. 7. The loss of fat and albu min in thyroid feeding shows a plain analogy with the same process in Base dow's disease and is toxic when it reaches a high grade. Thyroid preparations must, therefore, be used cautiously in the treatment of obesity. A. Magnus Levy (Zeit. f. klin. Med., B. 33, p. 23S, '9S).
In rabbits thyroid substance produced a lowering of the blood-pressure, begin ning a few seconds after the injection and persisting, with an unchanged heart action. The fall in pressure is due to dilatation of the vessels. As substances having a similar action are found in the hypophysis extract and adrenal extract, and since, moreover, peptones have the same influence, no final conclusions can be drawn from the action of the thyroid extract upon the tone of the vessels. Bisla v. Fenyvessy (Wiener klin. Woch., Feb. 8, 1900).
It seems exceedingly probable that the untoward phenomena resulting from thyroid extirpation are dire to an in toxication, to some kind of an autoin fection, whose harmful influence is no longer counteracted by the normal ac tion of the thyroid gland. The effect of thyroid transplantation or implanta tion, together with the positive results produced by thyroid feeding or by the use of extracts, speaks for the action of the gland by means of a secretion,—that is, at a distance from the gland; and this is against the view that some have suggested, that the toxic substances are brought to the gland and there trans formed or rendered innocuous. The gland acts, therefore, not by virtue of storage or of direct blood purification. (J. W. Warren.) Substances which diminish the excita bility of the nervous system, bromide of potassium and antipyrine in particular, will diminish or suppress the convul sive symptoms following thyroidectomy. Gley (La Sem. Med., Apr. 13, '92).
In dogs the symptoms of tetanus caused by thyroidectomy can be over come by large doses of potassium bro mide. Fifty dogs thus kept alive two years and two six years after the opera tion. Same results obtained with hypo dermic injections of a concentrated solu tion of the substance of the thyroid gland, and with a solution of the gray matter of the brain of healthy dogs. Canizzaro (Deutsche med. Woch., No. 184, '92).
Intravenous injections of solutions of brain, testicle, or blood-serum have no such effects as the thyroid juice. Ex periments favoring the belief that the thyroid gland has the function of pre venting autointoxication, by transform ing the toxic products of tissue-change into substances easily eliminated. or by directly neutralizing them by its own secretion. Vassale (Review of Insanity and Nervous Dis., June, '92).