BIOSYNTHESIS OF COLCHICINE. TRACER STUDIES WITH CINNAMATE-3-14C, METHANOL-14C, AND ORNITHINE-2-14C

Portal absorption of 14C after ingestion of spiked milk with 14C-phenanthrene, 14C-benzo[a]pyrene or 14C-TCDD in growing pigs.

Polycyclic aromatic hydrocarbons (PAHs) and dioxins are lipophilic organic pollutants occurring widely in the terrestrial environment. In order to study the PAHs and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) transfer in the food chain, pigs have been fed with milk mixed either with 14C-phenanthrene, with 14C-benzo[a]pyrene or with 14C-TCDD. The analysis of portal and arterial blood radioactivi...

Conversion of Proline-14c to Collagen Trans-3-hydroxyproline-14c in the Chick Embryo.

trans-3-Hydroxy-nn-proline-3,4-3H was synthesized by reduction of N-carbobenzoxy-3-keto-DLproline methyl ester with NaBH4 (4). Uniformly labeled n-proline-r4C was obtained from New England Nuclear Corporation. Uniformly labeled 4-hydroxy-r.-prolineJ4C was generously donated to us by Dr. Chozo Mitoma. Seven-day-old chick embryos were obtained from the Duckworth Hatchery (Elkridge, Maryland) and ...

Reactions of 14C-ADP and 14C-ATP with washed platelets from rabbits.

The Biosynthesis of Polysaccharides. Incorporation of D-(1-14c)glucose and D-(6-14c)glucose into Plum-leaf Polysaccharides.

1. The utilization of specifically labelled d-glucose in the biosynthesis of plum-leaf polysaccharides has been studied. After these precursors had been metabolized in plum leaves, the polysaccharides were isolated from the leaves, and their monosaccharide constituents isolated and purified. 2. Both the specific activities and the distribution of (14)C along the carbon chains of the monosacchar...

A comparison of 13C nuclear magnetic resonance and 14C tracer studies of hepatic metabolism.

The gluconeogenic pathway from 13C-labeled substrates, each of which contained the 14C-labeled counterpart at a tracer level, has been followed in isolated rat liver cells and in isolated perfused mouse liver. The gluconeogenic flux from glycerol, the synthesis of glycogen, the stimulation of glycogenolysis by glucagon, the recycling of triacylglycerol, and an increase in pentose cycle activity...