Bilirubin in Urine and Other Secretions apart from the Bile and in the Cereorospinal and Eye Liquors

Abstract

Summary. In patients with pronounced jaundice the sweat, tears, saliva and gastric juice were found to be bilirubin‐free. The behavior of milk in pronounced jaundice is yet unknown. The renal threshold for bilirubin is in the adult about 5 mg. per 100 ml. of serum (3–7 and occasionally as high as 11). The bilirubin clearance is very low (0.1–0.5) and does not show any close correlation to the urea clearance. The excretion of bilirubin in the kidneys seems to take place by secretion by the tubular epithelia only and the ability of the kidneys to excrete bilirubin is very limited. The individual variations of the renal threshold and the clearance for bilirubin are considerable. The cerebrospinal and eye liquors are entirely bilirubin‐free in most cases of jaundice. Only in cases of pronounced and longstanding jaundice may traces of bilirubin (below 1% of the serum concentration) be found.

Dialyzability, Protein Binding, and Renal Excretion of Plasma Conjugated Bilirubin*

“…The range of values for CB/GFR in the patients in this report corresponds to that reported by With (8) and by Wallace and Owen (20) in larger groups of jaundiced patients. The values for CB/GFR in the dogs (Table II) are in a range similar to that previously reported from this laboratory in a larger series of animals (9).…”

“…Most subsequent investigators, however, have maintained that neither conjugated nor unconjugated bilirubin was dialyzable or ultrafilterable from plasma (4)(5)(6)(7). This led to the hypothesis that conjugated bilirubin was probably excreted in the urine by a process of renal tubular secretion (8).…”

The Significance of the “One-Minute” (Prompt Direct Reacting) Bilirubin in Serum 1

“…Thus, Rissel (35) has reported a greater renal clearance of bilirubin in mechanical obstructive than in hepatocellular jaundice, which can be correlated with differences in creatinine clearance. This difference in bilirubin clearance has been confirmed by Enachesco, Comanesco and Zamfiresco (53), but not by With (12), who has also failed to find a significant correlation between bilirubin and urea clearances (34).…”

“…Since all of the bilirubin in serum is protein-bound (11,14,(26)(27)(28) and that in urine protein-free (11), it is probable that excretion occurs predominantly by way of the tubules rather than by glomerular filtration (34). The most perplexing problem is the relationship of the urinary excretion of bilirubin to its concentration in blood.…”

“…There is contradictory evidence, however, indicating that there is no causal relationship between biliuria and the type of van den Bergh reaction ( 12). Moreover, there is evidence to suggest that renal factors may be important in the excretion of bilirubin (34,35).…”