The metabolites of all-trans-[3H]retinoic acid appearing in the intestines of bile duct-cannulated rats were compared to those of similarly treated intact rats. 2.4% of administered radioactivity was found in the small intestines of bile duct-cannulated rats 2 H after dose, while a much larger proportion of the dose (7.2%) was found in the intestines of the intact rats. All-trans- and 3-cis-ret...

OBJECTIVE To evaluate the safety, dose tolerance, and anti-tumor effects of 9-cis-retinoic acid in the treatment of Kaposi sarcoma (KS) related to acquired immunodeficiency syndrome (AIDS). DESIGN Phase 2, open-label clinical trial of oral doses of 9-cis-retinoic acid increasing in 40-mg increments every 2 weeks from 60 mg/m(2) per day to a maximum of 140 mg/m( 2) per day. SETTING Five hosp...

All-trans-retinoic acid (at-RA) induces cell differentiation in a wide variety of cell types, including F9 embryonic teratocarcinoma cells, and can influence axial pattern formation during embryonic development. We now identify a novel retinoid synthetic pathway in differentiating F9 cells that results in the intracellular production of 4-oxoretinol (4-oxo-ROL) from retinol (vitamin A). Approxi...

The transition from mitosis to meiosis is unique to germ cells. In murine embryonic ovaries and juvenile testes, retinoic acid (RA) induces meiosis via the stimulated by retinoic acid gene 8 (Stra8), but its molecular pathway requires elucidation. We present genetic evidence in vivo and in vitro that neuregulins (NRGs) are essential for the proliferation of spermatogonia and the initiation of m...

Young adult wild-type and aryl hydrocarbon receptor knockout (AHRKO) mice of both sexes the C57BL/6J background were exposed to 10 weekly oral doses 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD; total dose 200 ?g/kg bw) further characterize observed impacts AHR as well TCDD on retinoid system. Unexposed AHRKO harboured heavier kidneys, lighter livers lower serum all-trans retinoic acid (ATRA) reti...

An understanding of the differences and similarities of the retinoid X receptor (RXR) and retinoic acid receptor (RAR) systems requires knowledge of the diversity of their family members, their patterns of expression, and their pharmacological response to ligands. In this paper we report the isolation of a family of mouse RXR genes encoding three distinct receptors (RXR alpha, beta, and gamma)....