ABSTRACT
Reversibly switchable proteins are powerful tools with which to explore protein function in vitro and in vivo. For example, the activity of many proteins fused to the hormone-binding domain of the modified oestrogen receptor (ER(TAM)) can be regulated by provision or removal of 4-hydroxytamoxifen (4-OHT). Despite the widespread use of ER(TAM) fusions in vivo, inadequate data are available as to the most efficacious routes for systemic tamoxifen delivery. In this study, we have used two well-characterized ER(TAM) fusion proteins, both reversibly activated by 4-OHT, to compare the effectiveness and kinetics of 4-OHT delivery in mice in vivo by either tamoxifen in food or by intraperitoneal injection. Our data indicate that dietary tamoxifen offers an effective, facile and ethically preferable means for long-term activation of ER(TAM) fusion proteins in vivo.
Subject(s)
Antineoplastic Agents/administration & dosage , Receptors, Estrogen/genetics , Tamoxifen/analogs & derivatives , Administration, Oral , Animals , Antineoplastic Agents/pharmacology , Genes, Reporter , Injections, Intraperitoneal , Islets of Langerhans/drug effects , Islets of Langerhans/metabolism , Kinetics , Mice , Rats , Receptors, Estrogen/biosynthesis , Recombinant Fusion Proteins/biosynthesis , Recombinant Fusion Proteins/genetics , Tamoxifen/administration & dosage , Tamoxifen/pharmacology , Transcriptional Activation/drug effects , Tumor Suppressor Protein p53/biosynthesis , Tumor Suppressor Protein p53/geneticsABSTRACT
Phenolics of grapes are the main compounds responsible for color, taste, mouth feel, oxidation and other chemical reactions in wine and juice. Phenolic levels in wine and juice are affected by numerous processing conditions (crushing, pressing, sulfite addition, skin contact, oak aging). Studies were conducted to better understand the effect of processing on phenolic composition of three varieties of grapes. Three different processing steps: immediate press, hot press, and hull treatment (skin contact) for 7 and 14 days were applied to three different grape varieties, Vitis rotundifolia cv. Noble, Vitis vinifer cv. Cabernet Sauvignon, and the French-American hybrid Chambourcin. Phenolic compounds were identified and quantified by High Performance Liquid Chromatography (HPLC) and bitterness/astringency were assessed using a trained sensory panel. V. rotundifolia wines had higher levels of epicatechin and gallic acid but lower caftaric acid and procyanidins compared to the other varieties and were more astringent and bitter. Processing treatment affected phenolics and color differently among the three varieties.
