In primary cultures of adult rat hepatocytes the level of cholesterol 7-alpha-hydroxylase steady-state mRNA markedly decreased by 72 h. However, the addition of L-thyroxine (T4) and dexamethasone synergistically returned cholesterol…
Cholesterol 7alpha-hydroxylase, the rate-determining enzyme in the bile acid biosynthesis pathway, is regulated in a negative feedback manner by hydrophobic bile salts returning to the liver via the portal circulation. The role of cholesterol in the…
Purified cholesterol 7 alpha-hydroxylases (C7 alpha H) from human and rat liver microsomes, and from transformed Escherichia coli expression systems, were incubated with 0.3 mmol/L [gamma-P-32] adenosine triphosphate (ATP) in the presence and absence…
Bile acids activate a nuclear receptor, farnesoid X receptor (FXR), that induces bile salt export pump (BSEP) but inhibits cholesterol 7alpha-hydroxylase (CYP7A1) gene transcription in the liver. Guggulsterone, a plant sterol that lowers serum…
Background/Aims: The decrease in cholesterol 7 alpha-hydroxylase induced by intraduodenal infusion of taurocholate in bile fistula vats may be indirect, i.e., mediated through release or absorption of an intestinal factor in response to the presence…
Cholesterol 7-alpha-hydroxylase catalyzes the rate-limiting step in the bile acid biosynthetic pathway. Regulation of this pathway is thought to occur solely as a result of a negative feedback control mechanism that is dependent upon the flux and…
The present study examines the feedback control governing human cholesterol 7 alpha-hydroxylase mRNA expression in the human hepatoblastoma cell line, Hep G2. Glycochenodeoxycholate (GCDC) and glycodeoxycholate, hydrophobic bile salts, decreased…
The gene for cholesterol 7 alpha-hydroxylase (CYP7A1) contains a sequence at nt -149 to -118 that was found to play a large role in determining the overall transcriptional activity and regulation of the promoter. Hepatocyte nuclear factor 4 (HNF4)…
Oxysterol 7 alpha-hydroxylase has broad substrate specificity for sterol metabolites and may be involved in many metabolic processes including bile acid synthesis and neurosteroid metabolism, The cloned human oxysterol 7 alpha-hydroxylase (CYP7B1)…
