5i 6 UREMIA; AMMOXIEMIA; URIC-ACID DYSCRASIA. 



Repeated inhalation of carbon monoxid is said occasionally to be attended 

 with polyuria, perhaps in consequence of paralysis of the center for the vasomotor 

 nerves of the kidneys. 



According to Cl. Bernard, irritation of the vagus at the cardia causes increased 

 secretion of urine, with reddening of the blood in the renal veins. Possibly this 

 nerve contains vasodilator fibers that behave similarly to the corresponding fibers 

 in the facial nerve for the salivary glands. The vagus innervates the intrinsic 

 unstriated musculature of the kidney. 



According to Arthaud and Butte and others, irritation of a peripheral ex- 

 tremity of the vagus, conversely, diminishes the secretion of urine and the circu- 

 lation in both kidneys. Atropin renders the experiment impossible. The vagus 

 thus appears to be the vasomotor nerve of the kidney. According to Boeri, it 

 possesses trophic functions, as albuminuria occurs after division of the vagus. 

 Irritation of the cervical sympathetic likewise diminishes the secretion. This 

 irritation appears to be reflex, being transmitted through the spinal cord to the 

 splanchnic nerve. 



UREMIA; AMMONIEMIA; URIC-ACID DYSCRASIA. 



After extirpation of the kidneys, nephrectomy, or ligation of the ureters, which 

 renders further secretion of urine impossible; further, also, in human beings, as 

 a result of extreme urinary stasis, as well as in consequence of morbid alterations 

 in the kidneys (inflammation, fatty degeneration, and desquamation of the epithe- 

 lial cells of the urinary tubules, cicatricial contraction of the kidney, amyloid 

 degeneration) , there develop a series of characteristic phenomena that resemble 

 an intoxication, and, if of marked degree, cause death, with degeneration of the 

 ganglia in the cerebral cortex and the spinal cord. This condition is designated 

 uremic intoxication or uremia. Among the phenomena, the following are con- 

 spicuous: Mental prostration, somnolence, even loss of consciousness to the point 

 of deep coma, and, in addition, from time to time, the occurrence of twitching 

 or even widespread, severe convulsions. Occasionally, there are delirium and 



feneral excitement. At the same time, the occurrence of the so-called Cheyne- 

 tokes respiratory phenomenon is often observed. Occasionally, transitory^ in- 

 variably bilateral, blindness occurs, from toxic paralysis of the psycho-optic 

 center. There may, however, take place, quite independently, hemorrhagic 

 extravasations into the retina, causing, rarely permanent, blindness apoplectic 

 retinitis. Also impairment of hearing is observed. Vomiting and diarrhea are 

 common. Ammonium carbonate, formed in the digestive tract from urea, as well 

 as kreatin, causes uremip diarrhea. Also the breath and the emanation from the 

 skin may exhale the odor of ammonia. The alkalinity of the blood and the 

 amount of oxygen in the blood are diminished. The retention of substances that 

 are normally excreted by the urine must be considered as the cause of these 

 symptoms, although it has not, as yet, been possible to designate with certainty 

 the substances that must be considered as the agents upon which the toxic 

 phenomena depend. 



Suspicion was first directed to urea. v. Voit observed that even healthy 

 dogs exhibited uremic manifestations when they partook of urea for a considerable 

 time with their food if. at the same time, the use of water, which would have 

 carried off the urea rapidly through the kidneys, was prevented. Further, Meissner 

 found that death amid uremic manifestations could be hastened in nephrectomized 

 animals, if urea was at the same time injected into the blood. An injection of 

 moderate amounts of urea into the blood of entirely healthy animals was not, 

 it is true, followed by uremic symptoms, although one or two grams caused a 

 comatose state in rabbits. Dogs died after subcutaneous injection of urea to an 

 amount equaling one per cent, of the bodily weight. Hippuric acid is said to 

 have an entirely similar effect in frogs. Although urea, when introduced into the 

 blood in large amounts, causes death with convulsions, this condition should not 

 be confounded with uremic attacks of intermittent occurrence. 



As injection of ammonium carbonate causes symptoms similar to those of 

 uremia, v. Frerichs and Stannius believed that the decomposition of urea in the 

 blood causes the intoxication ammoniemia. However, after nephrectomy or 

 ligation of the ureters, even on simultaneous injection of urea into the blood, 

 careful chemical investigation fails to disclose the presence of ammonia in the 

 blood. Therefore, spontaneous formation of ammonia in the blood cannot be the 

 cause of the uremic symptoms. 



