Porphyrin-Heme Pathway: Regulation by Intermediates in Bile Acid Synthesis

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Science  23 Nov 1973:
Vol. 182, Issue 4114, pp. 841-842
DOI: 10.1126/science.182.4114.841


Dihydroxycoprostane and trihydroxycoprostane, intermediates in normal bile acid synthesis in the liver, enhanced the rate of porphyrin synthesis in cultured liver cells by induction of δ-aminolevulinate synthetase, the rate-limiting enzyme for this pathway. Other 5β-cholestane derivatives and cholest-5-ene derivatives were ineffective. The selectivity of the induction may indicate that the above-mentioned coprostanes have a physiological role in porphyrin synthesis.