9-cis-Retinoic acid is a naturally occurring biologically active retinoid capable of binding and transactivating both the retinoic acid receptors and the retinoid X receptors. A study was performed to characterize the pharmacokinetics 9-cis-retinoic acid following i.v. bolus administration in the nonhuman primate. Groups of three animals received i.v. bolus doses of 9-cis-retinoic acid of eithe...

We describe a rapid and simple procedure for the simultaneous quantitation of endogenous 13-cis-retinoic acid, all-trans-retinoic acid, and retinol by isocratic normal-phase HPLC with ultraviolet detection, in 0.5 mL of human plasma. A silica adsorption column was eluted with n-hexane:2-propanol:acetic acid (200:0.7:0.135 by vol) at 0.9 mL/min, and the effluent monitored at 350 nm. The arotinoi...

The molecular signaling events involved in the inhibition of breast cancer cell growth by retinoic acid and interferon-alpha were investigated. All-trans-retinoic acid and interferon-alpha acted synergistically to inhibit growth of both the estrogen receptor-positive breast cancer cell line MCF-7 and the estrogen receptor-negative line BT-20. In MCF-7 cells, all-trans-retinoic acid potentiated ...

The retinoids, the natural or synthetic derivatives of Vitamin A (retinol), are essential for the normal development of prostate and have been shown to modulate prostate cancer progression in vivo as well as to modulate growth of several prostate cancer cell lines. 9-cis-retinoic acid and all-trans-retinoic acid are the two most important metabolites of retinol. Gap junctions, formed of protein...

BACKGROUND Retinoids are vital for embryonic development; both excesses and deficiencies of vitamin A are known to give similar patterns of birth defects. Concentrations of retinol in newborns and in pregnant women have been investigated, but concentrations of the biologically active metabolite all-trans retinoic acid and its isomer 13-cis retinoic acid have not. OBJECTIVE We measured serum c...

BACKGROUND The overall survival rate for patients with neuroblastoma has improved over the past two decades, but long-term survival for the subgroup of patients with high-risk disease remains low. In recent years, there has been interest in the potential clinical use of drugs able to induce differentiation of neuroblastoma cells. Since 9-cis-retinoic acid induces better and more sustained diffe...

Retinoic acid receptor (RAR) and retinoid X receptor are ligand-induced transcription factors that belong to the nuclear receptor family. The receptors are activated by small hydrophobic compounds, such as all-trans-retinoic acid and 9-cis-retinoic acid, respectively. Interestingly, these receptors are also targets for a number of exogenous compounds. In this study, we characterized the biologi...

Previous observations have suggested that retinoids might be useful for the treatment of rheumatoid arthritis. In this study we examined the effects of various retinoids on collagenase production by adherent human peripheral blood mononuclear cells in culture. We have previously shown that these cells, consisting predominantly of monocyte-macrophages, actively synthesize and secrete collagenase...

Two mammalian hCYP26A expression systems have been used to analyze the metabolic products of CYP26A. Through the use of extensive HPLC, UV spectroscopy, and liquid chromatography/tandem mass spectrometry (LC-MS/MS) methodology, we have conclusively demonstrated that the complex mixture of products comprises 4-OH-all-trans-retinoic acid, 4-oxo-all-trans-retinoic acid, and 18-OH-all-trans-retinoi...