Bile Salt Composition and Distribution of the D-Cysteinolic Acid Conjugated Bile Salts in Fish

Abstract

Bile salts in twenty six species of fish were examined to investigate the bile salt composition and the distribution of D-cysteinolic acid conjugated bile salts by high-performance liquid chromatography and/or thin-layer chromatography densitometry. Their major bile salts were cholyltaurine and/or chenodeoxycholyltaurine except for the bile salt in Japanese dace which exclusively consists of cyprinol sulfate. A considerable amount of unconjugated cholate was also found in ayu fish. D-Cysteinolic acid conjugates were detected in the bile of wild and aquacultured guelly jack, brackish goby and marbled rockfish as well as red seabream. No D-cysteinolic acid conjugates was found in biles of Japanese sardine and mackerel in spite of existences of D-cysteinolic acid in their muscle and liver.