Conjugated bile acids activate the sphingosine-1-phosphate receptor 2 in primary rodent hepatocytes.

Bile acids have been shown to be important regulatory molecules for cells in the liver and gastrointestinal tract. They can activate various cell signaling pathways including extracellular regulated kinase (ERK)1/2 and protein kinase B (AKT) as well as the G-protein-coupled receptor (GPCR) membrane-type bile acid receptor (TGR5/M-BAR). Activation of the ERK1/2 and AKT signaling pathways by conjugated bile acids has been reported to be sensitive to pertussis toxin (PTX) and dominant-negative Gα(i) in primary rodent hepatocytes.

Guided cartilage regeneration using resorbable template.

Objective: The reconstruction of a defect involving complex cartilaginous structures such as the ear and nose is a difficult problem. Cartilage donor sites are limited, and the shaping of an ear or nose is dependent upon the surgeon's skills and experience. In this report, we propose to use resorbable plates that can be shaped to serve as a template for cartilage healing.

Transport of cholesterol into mitochondria is rate-limiting for bile acid synthesis via the alternative pathway in primary rat hepatocytes.

Bile acid synthesis occurs mainly via two pathways: the "classic" pathway, initiated by microsomal cholesterol 7alpha-hydroxylase (CYP7A1), and an "alternative" (acidic) pathway, initiated by sterol 27-hydroxylase (CYP27). CYP27 is located in the inner mitochondrial membrane, where cholesterol content is very low. We hypothesized that cholesterol transport into mitochondria may be rate-limiting for bile acid synthesis via the "alternative" pathway.

Expression of sterol 12alpha-hydroxylase alters bile acid pool composition in primary rat hepatocytes and in vivo.

Background & Aims: The rate of 12alpha-hydroxylation of bile acid intermediates is believed to determine the ratio of cholic acid (CA) to chenodeoxycholic acid (CDCA) biosynthesis and the overall hydrophobicity of the bile acid pool. The aim of this study was to determine the effects of the level of expression of sterol 12alpha-hydroxylase (CYP8b1) and cholesterol 7alpha-hydroxylase (CYP7a1) on rates of CA biosynthesis and bile acid pool composition.

Methods: Expression of CYP8b1 and CYP7a1 was accomplished through infection of primary rat hepatocytes (PRH) or intact male SD rats with replication-defective recombinant adenoviruses encoding either CYP8b1 or CYP7a1.

High-performance liquid chromatography assay for 3 beta-hydroxy-delta 5-C27-steroid oxidoreductase activity in rat liver microsomes.

A quantitative HPLC method has been developed for measuring 3 beta-hydroxy-delta 5-C27-steroid oxidoreductase activity in rat liver microsomes. Apparent Km values of 23 and 27 microM were estimated for 5-cholestene-3 beta,7 alpha-diol and NAD+, respectively. A temperature optimum of 45 degrees C was estimated using standard assay conditions.

Cholesterol and bile acid metabolism in cultures of primary rat bile ductular epithelial cells.

The role of hepatocytes in bile acid and cholesterol metabolism has been extensively studied. By contrast, nothing is known about the role of bile ductular epithelial cells in cholesterol and bile acid metabolism. The purpose of the current studies was to establish whether bile ductular epithelial cells synthesize cholesterol, bile acids or both and to determine whether these cells are capable of metabolizing (hydroxylating, conjugating) bile acids.

Effect of zinc on cadmium influx and toxicity in cultured CHO cells.

Addition of zinc lowers the toxicity level of cadmium in cultured CHO cells. Cell survival and protein synthesis were used to measure the cellular toxicity of cadmium.(109)Cd was used to measure cadmium uptake by the cells.