Effects of haem infusion on biliary secretion of porphyrins, haem and bilirubin in man

Abstract

Employing a continuous bile collection, the bile secretion of porphyrins, heme (Fe protoporphyrin IX regardless of oxidation state) and bilirubin was measured in 5 healthy subjects. The baseline values for the flow of porphyrins in the bile were: 4.7 .+-. 1.9 nmol/h uroporphyrin, 27.3 .+-. 3.8 nmol/h coproporphyrin and 39.2 .+-. 11.7 nmol/h protoporphyrin. Bile heme flow was 59.7 .+-. 12.6 nmol/h and that of bilirubin 23.8 .+-. 8.2 .mu.mol/h. Following heme injection (6.4 .mu.mol/kg) the flow of protoporphyrin, but not of the other porphyrins was reduced and the bile heme flow increased (232 .+-. 109.5 nmol/h), while the flow of bilirubin did not increase significantly. A few patients with representative porphyrias showed the expected increase in copro- and protoporphyrin the bile. The patient with coproporphyria exhibited a bile flow of coproporphyrin of 1470 .+-. 133 nmol/h and of protoporphyrin of 334 .+-. 29 nmol/h; heme infusion significantly reduced the bile flow of both porphyrins (to 649 .+-. 101 for copro- and 215 .+-. 36 nmol/h for protoporphyrin). The patient with protoporphyria had an increased protoporphyrin flow, yet heme infusion caused no reduction in protoporphyrin flow (106 .+-. after v. 81.4 .+-. 13 nmol/h before heme). Heme and porphyrins apparently are normal constituents of bile. Injected heme does appear in bile. Bile bilirubin did not rise within 12 h afterheme infusion a finding which warrants further investigation.