There is increasing awareness that exposure to endocrine disrupters interferes with lipid homeostasis in vertebrates, including fish. Many of these compounds exert their action by binding nuclear receptors, such as peroxisome proliferator-activated receptors and retinoid X receptor. This work investigates the use fish liver cells (PLHC-1 ZFL cells) for screening metabolic aquatic environment as...

A three-step purification has been developed for the cellular retinoland cellular retinoic acid-binding proteins from extracts of bovine retina. The two binding proteins elute together in Step 1 (gel filtration) and separate in Step 2 (DEAE-cellulose chromatography), and each is purified to apparent homogeneity in the third step (calcium phosphate gel chromatography). The retinoland retinoic ac...

A three-step purification has been developed for the cellular retinoland cellular retinoic acid-binding proteins from extracts of bovine retina. The two binding proteins elute together in Step 1 (gel filtration) and separate in Step 2 (DEAE-cellulose chromatography), and each is purified to apparent homogeneity in the third step (calcium phosphate gel chromatography). The retinoland retinoic ac...

Retinoic acid is known to cause the cell cycle arrest and myeloid differentiation of HL-60 myeloblastic leukemia cells. Evidence suggesting the possible involvement of the Fc RII immunoglobulin receptor in mediating retinoic acid-induced growth arrest and differentiation of HL-60 cells is presented. HL-60 cells stably transfected with the 205 mutant polyoma middle T antigen, a largely debilitat...

Liarozole is a new imidazole derivative with antitumoral properties. Effects of the compound alone and in combination with all-trans-retinoic acid on proliferation of MCF-7 human breast cancer cells were examined using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide assay. Following 9 days of drug exposure, MCF-7 cell growth was concentration dependently inhibited by all-tran...

The steric conversion of 13-cis-retinoic acid (13-cRA) to all-trans-retinoic acid (t-RA) has been proposed as an activation mechanism for the observed therapeutic and teratogenic activities of 13-cRA. Here we have investigated the catalysis of isomerization of 13-cRA to t-RA by recombinant human glutathione S-transferases (GSTs). Substrate was incubated with GST in 0.1 M sodium phosphate buffer...

Interleukin-6 (IL-6)/IL-6 receptor (IL-6R) plays a major role in autocrine/paracrine growth regulation of myeloma cells. We investigated the effect of dexamethasone and all-trans retinoic acid, previously shown to modulate IL-6/IL-6R, on the in vitro growth of a human myeloma cell line, OPM-2. Both agents inhibited the clonogenic growth and 3H-thymidine incorporation in a concentration-dependen...

The purpose of this study was to investigate whether and to what extent the steric isomerization of retinoic acids in conceptal tissues can be attributed to enzymatic catalysis in addition to thiol-dependent, nonenzymatic catalysis. Conversions of 13-cis-retinoic acid and 9-cis-retinoic acid to all-trans-retinoic acid catalyzed by cell-free preparations of conceptal rat tissues (gestational day...

Previous studies in our laboratory showed a synergistic interaction of synthetic ligands selective for the retinoid receptors RAR and RXR in regard to teratogenic effects produced in mice (M. M. Elmazar et al., 2001, TOXICOL: Appl. Pharmacol. 170, 2-9). In the present study the influence of phytol and phytanic acid (a RXR-selective ligand) on the teratogenicity of retinol and the RAR-selective ...