We have investigated pathways of lipid metabolism in boar spermatozoa sperm cells incubated for up to 3 days with [14C]palmitic acid, [14C]glycerol, [14C]choline, or [14C]arachidonic acid or incorporated these precursors into diglycerides and/or phospholipids. When spermatozoa were incubated with [14C]palmitic acid or [14C]glycerol, there was first an incorporation into phosphatidic acid, follo...

Male and female Sprague-Dawley rats received repeated oral administration of 14C-2,6-dichloro-4-(3,3-dichloroallyloxy)phenyl 3- [5-(trifluoromethyl)-2-pyridyloxy]propyl ether (14C-pyridalyl) at 5 mg/kg/day for 14 consecutive days, and 14C excretion, 14C concentration in tissues, and the metabolic fate were determined. Most 14C was excreted into feces. The 14C concentrations in the blood and tis...

Hepatic biotransformation of bilirubin to the hydrophilic species bilirubin mono- (BMG) and diglucuronide (BDG) by microsomal bilirubin UDP-glucuronosyl-transferase (GT) is a prerequisite for its physiologic excretion into bile. The reaction mechanism of bilirubin-GT and the access of bilirubin and BMG (the intermediate substrate) to the active site of bilirubin-GT are undefined. Highly purifie...

: BHK-21-cI3 fibroblasts were incubated with [I-3H, U-14C]glucose or 14C]glucose to produce intracellular [3H]NADPH via the phosphogluconate pathway. 3H and 14C were then determined at the th~ee positions of glycerol in glycerol phosphate, saponifiable glycerolipids, alkyl ether glycerolipids and plasmalogens. The 3H/14C ratio at C-2 in glycerol of saponifiable glycerolipids is 2-10 fold greate...

OBJECTIVE To study the metabolism of 14C-deltamethrin in rats. METHODS Rats were dosed orally and i.p. with a single dose of 14C-deltamethrin (0.64 mg/Kg) body weight. The required dose was applied daily for 3 days. At the end of the experiment, selected organs, such as liver, kidney, fat, intestine, and blood were excised for radioassay of 14C-content. RESULTS Deltamethrin was almost elimi...

Radiocarbon (14C) ages of acetogenic lipid biomarkers such as n-alkanes represent a powerful tool to track carbon-cycle turnover times in range environments including soils, fluvially exported sediments, and marine sediments. However, the fidelity this approach requires that biomarker 14C accurately reflect time has passed since biosynthesis are not complicated by issues isotope fractionation. ...

After oral and intravenous administration of [14C]clarithromycin to rats, c. 60-70% of the radioactivity in the gastric tissue was found to be distributed in the mucosal layer. Co-administration of lansoprazole and amoxicillin had no apparent effect on this distribution pattern of [14C]clarithromycin. The amount of unchanged [14C]clarithromycin in gastric contents increased with co-administrati...

The overall metabolism o f [8-l4C]adenine, [8-14C]adenosine, [8-l4C]guanine, [8-14C]hypoxanthine and [8-14C]inosine in suspension cultured cells o f the lag, cell division, cell expansion and stationary phases and stem tissue o f Catharanthus roseus was studied. On a fresh weight basis, absorption o f all purine bases and nucleotides by the cultured cells was 10 —400 times higher than that by t...

Pulmonary surfactant is a lipid:protein complex containing dipalmitoyl-phosphatidylcholine (DPPC) as the major component. Recent studies indicate adsorbed surfactant films consist of a surface monolayer and a monolayer-associated reservoir. It has been hypothesized that the monolayer and its functionally contiguous reservoir may be enriched in DPPC relative to bulk phase surfactant. We investig...

The scheme of biosynthesis of noradrenaline from dopa in the mammalian tissues was presented by Blaschko (1). The conversion of dopamine to noradrenaline, mediated by dopamine-Q-hydroxylase (2), was shown to occur in the intracellular granules of the adrenal medulla (3) and heart (4, 5). The administration of tyrosine-14C (6) or dopa 14C (7 , 8) to rats results in formation of noradrenaline-14C...