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Biomedical subjects

J R Fouts

Publications and source records attributed to J R Fouts.

At least 55 records · Page 3Linked to original sources
PubMed1976

Relationship between induction of aryl hydrocarbon hydroxylase and de novo synthesis of cytochrome P-448 (P1-450) in mice.

Phenobarbital, 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT), benzpyrene, 3-methylcholanthrene (3-MC) or 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) were administered i.p. for 1 or 3 days to genetically "responsive" (C57BL/6J) and genetically "non-responsive" (DBA/2J) mice. 3-MC or benzpyrene stimulated aryl hydrocarbon hydroxylase (AHH) activity in C57BL/6J (B6) mice but not in DBA/2J (D2) mice. TCDD induced AHH activity in both B6 and D2 mice. Time-course studies showed that in the first 12 h after a single injection of 3-MC to B6 mice there was no shift in the reduced cytochrome P-450-CO complex absorption spectra from 450 to 448 nm, although AHH activity increased 4-5 times over (above) that of the control group. The relationship between induction of AHH activity by polycyclic hydrocarbons in B6 mice and the concomitant synthesis of cytochrome P-448 is discussed.

Animals↗
PubMed1975

The liver parenchyma and foreign compound metabolism in red-winged blackbird compared with rat.

1. Aniline p-hydroxylase, aminopyrine N-demethylase, and p-nitroanisole O-demethylase activities were measured in liver microsomes prepared from the red-winged blackbird (Agelaius phoeniceus) and compared with analogous preparations from rat. All had lower activities in birds than in rats, when expressed in terms of microsomal protein. 2. Hepatic parenchyma of the bird was observed by electron microscopy to contain less endoplasmic reticulum than that of rat. This morphological difference may partially explain the species difference in enzyme activities. 3. Cytochrome P-450 levels were not sex-dependent in the red-winged blackbird, unlike rat, but the opposite was true for the rate of hydroxylation of aniline. 4. There was no species difference in the activity of aniline p-hydroxylase when expressed in terms of activities per unit of cytochrome P-450, but the activity of p-nitroanisole O-demethylase was higher in red-winged blackbird than in rat; the reverse may be true for the activity of aminopyrin N-demethylase.

Aminopyrine N-Demethylase↗
PubMed1973

Hepatic lipid droplets. Isolation, morphology and composition.

The floating lipid layer isolated centrifugation of rat liver was examined for composition and ultrastructure. It was chiefly composed of triglycerides and cholesterol esters plus much smaller amounts of free cholesterol, diglycerides, phospholipid and protein. No free fatty acids were detected. The triglyceride and cholesterol ester fractions consisted mostly of esters of linoleic acid, oleic acid and palmitic acid. Electron micrographs of the floating lipid layer revealed numerous spherical osmiophilic droplets having a mean diameter of 0.5-2mum with a very-thin dense outer coat. Similar structures were observed as organelles in electron micrographs of the intact liver cell. The amount of triglyceride in the layer decreased in rats starved for 72h, but pellet triglyceride (homogenate minus the floating lipid layer) was unchanged. These results suggest that the floating lipid layer is the representative in vitro of lipid-rich organelles which probably function as a depot form of hepatic-cell neutral lipid.

Animals↗