Elimination of Urine and Dye by Aglomerular and Glomerular Kidneys.

Abstract

Detailed anatomical studies were made preliminary to quantitative analyses of blood (plasma) and urine taken simultaneously from certain fish (teleosts). These studies establish definitely the character of the renal tubule and the blood supply to the kidney. In the aglomerular kidney, the blood supply is solely venous. In the glomerular kidney it is venous and arterial. Although arterial vascularization is apparently the necessary accompaniment of glomerular development, no definite relation obtains between the number of glomeruli developed and the number of tubules connected with them. All stages are found from no glomeruli to few or many. In 4 genera represented in 3 widely differing and unrelated families, the mesonephroi of which are (a) entirely aglomerular, (b) almost aglomerular, (c) predominantly glomerular, the blood and urine were analyzed for the commonly occurring constituents except uric acid and sulphates. The results of these analyses (analyses by Dr. Luigi Condorelli, Department of Clinical Pathology, the Royal University of Naples) show clearly that the urine eliminated by the 3 types of mesonephroi is closely comparable and also comparable to that eliminated by the kidney of higher vertebrates, including man.

The excretion of dye by these kidneys was also determined quantitatively and found to be comparable. As far as could be determined by direct observation of the tubule in the aglomerular kidney of the living fish, which was accomplished with partial success under great difficulty, it appears that the entire tublule is colored by the dye a short time after its injection. Intraperitoneal injections of from 0.6 mg. of the dye, tetrachlorphenolsulphonephthalein, in a 3-gm. fish to 6 mg. in one weighing 2 kilograms, result in the total elimination of the dye within 15 hours as follows: 1. Aglomerular kidney weighing from 50 to 80 mg.; amount injected 0.6 mg. to 1.2 mg.; 30% elimination by the kidney and 70% in the bile. 2. Almost aglomerular kidney of a 2 to 3 kg. fish; amount injected, 10 mg. intravascularly; amount excreted by kidney within 30 minutes after injection, −20%; bile, none.