HEMATOGENOUS AND OBSTRUCTIVE ICTERUS : EXPERIMENTAL STUDIES BY MEANS OF THE ECK FISTULA.
Normal and Eck fistula dogs react in a similar manner to the intravenous injection of hemoglobin obtained from laked red cells of the same animal. Hemoglobin appears in the urine after a few minutes and bile pigments in one to one and one half hours. In this simple type of hematogenous jaundice the reaction is in no way influenced by shutting out the portal blood from the liver and cutting down its blood supply to about 25 per cent. of normal. In a second type of hematogenous jaundice produced by chloroform anesthesia, which produces central liver necrosis, there is no essential difference between the normal and Eck fistula dog. The Eck fistula dog, as a rule, is more resistant to this poison, but, given a definite liver necrosis, the jaundice developing will reach its maximum on the second day as in the normal animal. This jaundice must be explained in part by capillary biliary obstruction, but in part by a hemolysin formed in the injured liver cells (Joannovics and Pick). Simple obstruction of the common duct when combined with an Eck fistula gives rise to a definite low grade icterus with bile pigment constantly present in the urine. Under these conditions after doubly ligating and cutting the common duct with separation of the cut ends, the lumen of the duct may be established and bile may enter the intestine by means of a fistulous tract between the cut ends of the bile duct. The formation of bile and bile pigments is much less in an Eck fistula dog than in a normal animal and consequently the icterus is much less intense. This is probably due to a lessened activity of the liver cells because of decreased blood supply. This observation does not harmonize with the current view that bile pigments are formed solely from hemoglobin, as there is no evidence of more hemolysis in a normal than in an Eck fistula dog. This suggests that the bile pigment may be formed in part, at least, from other substances than hemoglobin, and, further, that bile pigment formation normally may depend in part upon the functional activity of the liver cell rather than upon the amount of hemoglobin supplied to it.
Hunterian Laboratory of Experimental Pathology, Johns Hopkins Medical School, Baltimore.
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Whiffle
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Hooper