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Biomedical subjects

D J Ecobichon

Publications and source records attributed to D J Ecobichon.

At least 73 records · Page 4Linked to original sources
PubMed1975

The metabolism of 4'chloro-4-biphenylol in the rat.

4'Chloro-4-biphenylol, the major metabolite of 4-chlorobiphenyl in the rat, was given intraperitoneally to rats, and the urine and feces were examined for possible metabolic degradation products. The structure of the major urinary metabolite was elucidated by mass and nuclear magnetic resonance spectroscopy and shown to be 4'-chloro-3,4-biphenyldiol. Two chloromethoxbiphenylols (m-4) were also identified in the urine extracts but they could not be separated by chromatographic procedures. Demethylation of the mixture gave 4'-chloro-3,4-biphenyldiol as the sole product, thus indicating that the two components of the mixture were 4'-chloro-3-methoxy-4-biphenylol and 4'-chloro-4-methoxy-3-biphenyldiol. No 4'-chloro-4-biphenylol metabolites were isolated in the fecal extracts, and mass spectrometric analysis of the crude urine and feces extracts did not reveal any chlorine-containing degradation products that could be derived by oxidative fission of the biphenyl nucleus.

Animals↗
PubMed1975

The development of kinetic parameters of hepatic drug-metabolizing enzymes in perinatal rats.

The development of the apparent kinetic parameters K- m and V-max was studied in perinatal Wistar rats for three functionally diverse, hepatic enzymes (p-nitroanisole O-demethylase, carboxylesterase and bromosulphophthalein-glutathione conjugating enzyme), the period studied being from 3 days prepatum to 35 days postpartum. The kinetic parameters underwent marked quantitative changes during development, which appeared to be independent of sex for the first 5 weeks postpartum.

Aging↗
PubMed1975

The influence of phenobarbitone on maternal and perinatal hepatic drug-metabolizing enzymes in the rat.

Phenobarbitone (PB) (75 mg/kg) was administered orally for three consecutive days to pregnant or lactating rats at different pre- and postnatal stages in order that the perinatal animals would receive the agent either by transplacental passage or via the milk. Control animals received equivalent volumes of saline. The dams, fetuses, and pups were killed 24 h after the last dose. Hepatic p-nitroanisole O-demetnylase (OD), carboxylesterase (CE), and bromosulfophthalein-glutathione (BSP-GSH) conjugating enzyme activities in a 12 100 g - 20 min supernatant of a 20% w/v homogenate were measured. The morphology of the developing rat liver in the absence and presence of PB was examined by electron microscopy. The results demonstrated that the transplacental passage of PB to rat fetuses at term or 3 days prepartum had no effect on either the hepatic drug-metabolizing enzyme activities or on the ultrastructural appearance of the liver. Increased hepatic OD activity was observed in the pregnant animal but no effect was observed in the lactating dam. Phenobarbitone received by the suckling rat had two distinct effects. Compared to control activities, twofold increases in hepatic OD activity were observed in rat pups as early as 4 days after birth, associated with a marked proliferation in hepatic smooth endoplasmic reticulum. In contrast, PB-related significant increases in neonatal hepatic CE and BSP-GSH conjugating enzyme activities were not observed until 21 days of age. In the 4-day-old treated pups, characteristic morphological changes included numerous small membrane whorls in addition to increased smooth endoplasmic reticulum and microbodies in the liver.

Animals↗