Selected monographs.

Date:: 1888

Catalogue details

Licence: Public Domain Mark

Credit: Selected monographs. Source: Wellcome Collection.

58/440 (page 42)

quantity of the secretion yielded by the epithelium^ instead of n, will be rather n + y, so that now the urine as passed will a—X contain only n + y of albumen^ always supposing that no ^ lOO absorption takes place from the urinary tubules. It follows, therefore, that if the experiments be really successful, and free from all objection, we may expect to find less albumen than normal in the urine; but simul- taneously with the increase of pressure, other conditions must prevail, which, without causing any other alteration, diminish the quantity of urine, and therefore raise its percentage of albumen, enabling us to demonstrate its presence. Let us consider once more the experiments that have hitherto been made, and their results in particular. There are various methods which may be used, and for the most part have been used, for the purpose of increasing the pressure in the arteries in general, or in those of the kidneys only. The greatest increase of pressure in the aorta can be produced with ease and precision by electrical irritation of the cervical spinal cord, by producing dyspnoea, by poisonous doses of strychnia, digitalis, &c. All these means have been employed to produce albuminuria, and it may be asked, with what result ? All observers agree in stating that invariably during the rise of the aortic pressure, and at its height, the flow of urine altogether ceases ; subsequently, when with the falling pressure secretion is restored and is more copious than before, a (gradually diminishing) excretion of albumen takes place. In the first period there is a general spasm of the small arteries, which causes the pressure to rise in the great trunks. The small renal arteries, as Griitzner (45) has shown, participate in this spasm, and the natural result is the exhaustion of the flow of urine ; with the subsidence of the vascular spasm, as a matter of course, there is increase of pressure in the arteries and capillaries of the kidneys (as in other organs), and exceeding the original height in a degree corresponding to the previously abnormal increase in the aorta, until the dilatation of the vascular channels causes the normal conditions to be restored. In this period, in which the pressure and the rapidity are both increased, with active