background: many in vitro studies suggested that choline incorporation into many types of tumors is related to cell proliferation. whether in vivo choline incorporation is related also to cell proliferation or not was my question. therefore, the aim of this pilot study was to investigate the relationship of in vivo [methyl- 14c]-choline incorporation and in vivo [methyl-3h]- thymidine incorpora...

In Coffea arabica leaves, the purine ring of theobromine (3,7-dimethylxanthine) and caffeine (1,3,7-trimethylxanthine) is provided by de novo purine biosynthesis: (a) [14C]glycine, [14C]bicarbonate, and [14C]formate were incorporated into inosine 5[prime]- monophosphate (IMP), sum of adenine nucleotides ([sigma]Ade), theobromine, and caffeine; and (b) incorporation of [14C]formate into IMP, [si...

To examine the fate of the carbons of acetate and to evaluate the usefulness of labeled acetate in assessing intrahepatic metabolic processes during gluconeogenesis, [2-14C]acetate, [2-14C]ethanol, and [1-14C]ethanol were infused into normal subjects fasted 60 h and given phenyl acetate. Distributions of 14C in the carbons of blood glucose and glutamate from urinary phenylacetylglutamine were d...

The occurrence of multiple herbicide resistant weeds has increased considerably in glyphosate-resistant soybean fields Brazil; however, the mechanisms governing this resistance have not been studied. In its study, target-site and nontarget-site were characterized an Eleusine indica population (R-15) with to acetyl-CoA carboxylase (ACCase) inhibitors, glyphosate, imazamox, paraquat. Absorption t...

Metabolism of L-[1-14C]methionine, DL-[1-14C]methionine and DL-[1-14C]2-hydroxy-4-methylthiobutanoic acid (DL-HMB) by broiler chicks which had been fasted overnight or given a methionine-deficient diet was compared with fed (control) birds. The excretion of 14C-labelled material, total 14CO2 exhaled, 14C incorporation into tissue proteins and the 14C-labelled material in perchloric-acid-soluble...

[6-14C]Glucose is the tracer sometimes recommended to assay cerebral glucose utilization (CMRglc) during transient or brief functional activations, but when used to study visual stimulation and seizures in other laboratories, it underestimated CMRglc. The metabolic fate of [6-14C]glucose during functional activation of cerebral metabolism is not known, and increased labeling of diffusible metab...

The glucose replacement rate, percent carbon recycling, mean glucose transit time, and the glucose mass were determined in fasted unanesthetized rabbits after administration of [2-3H,U-14C]-, [3-3H,U-14C]-, [5-3H,U-14C]- or [6-3H,U-14C]glucose using the procedures of Katz et al. (10). The glucose replacement rates and carbon recycling determined with [2-3H,U-14C] and [5-3H,U-14C]glucose are equ...

The present study examined the functional characteristics of the inward and outward L-[14C]DOPA and L-[14C]leucine transporters in LLC-PK1 cells. Uptake was initiated by the addition of Hanks' medium with a given concentration of L-[14C]DOPA or L-[14C]leucine. Saturation experiments were performed in cells incubated for 6 min with 0.25 microM concentration of the substrates in the absence and t...

Lividomycin inhibited incorporation of acetate-114C , glutamic acid-1-14C, leucine-1-14C, and glycine1-14C into protein of Mycobacterium smegmatis (strain Jucho). Incorporation of acetate-1-14C and glycine1-14C into nucleic acids was also inhibited, but incorporation of these compounds into lipids was not inhibited in the presence of lividomycin. Incorporation of uridine-2-14C into nucleic acid...

Simple methods are described for the preparation of //-<ms-[l-14C]monounsaturated fatty acids and c is-[l-14C]monounsaturated fatty acids, each with a fairly uniform distribution o f positional isomers, which can serve as mixed substrates in biochemical studies. Methyl trans[ l 14C]octadecenoates and methyl ir<m.s-[l-14C]eicosenoates are prepared by partial catalytic hydrogenation of methyl [1-...