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Biomedical subjects

D J Jollow

Publications and source records attributed to D J Jollow.

8 recordsLinked to original sources
PubMed1992

Dapsone-induced hemolytic anemia: effect of N-hydroxy dapsone on the sulfhydryl status and membrane proteins of rat erythrocytes.

Dapsone hydroxylamine (DDS-NOH), a known metabolite of dapsone, has recently been shown to be a direct-acting hemotoxin responsible in part for dapsone-induced hemolytic anemia in the rat. The effect of DDS-NOH on the morphology, sulfhydryl status, and membrane skeletal proteins of the rat red cell has been investigated. Exposure of rat red cells to a TC50 of DDS-NOH induced transformation of about 50% of the cells to an extreme echinocyte morphology. Reduced glutathione content of the cells was rapidly lost with concomitant increase in the formation of mixed disulfide between glutathione and the soluble protein of the cell. Oxidized glutathione content of the cells did not increase at any time during exposure to DDS-NOH. Examination of the skeletal membrane proteins by SDS-PAGE indicated that DDS-NOH caused the apparent loss of band 4.2, decrease in peaks 1, 2.1, and 3, and the appearance of new bands at about 16, 27, 40, and 54 kDa. Bands 4.1 and 7 appeared unchanged. Treatment of DDS-NOH altered proteins with dithiothreitol, reversed the protein changes, and indicated that the observed alterations were due to the formation of disulfide-linked adducts between hemoglobin and the various skeletal proteins as well as between hemoglobin monomers. The possible significance of the parallel changes in cell morphology and in membrane skeletal proteins for the premature splenic sequestration of the injured rat red cells is discussed.

Anemia, Hemolytic↗
PubMed1992

Galactosamine hepatotoxicity: effect of galactosamine on glutathione resynthesis in rat primary hepatocyte cultures.

The effect of galactosamine on the resynthesis of glutathione in rat primary hepatocyte cultures was investigated. Cultured rat hepatocytes were treated with galactosamine (4 mM) 1.5 hr prior to concurrent with, or 1.5 hr after cell attachment; total cellular glutathione was then measured over time. Addition of galactosamine at any of these times suppressed methionine-enhanced glutathione resynthesis in the cultures after a lag period of about 120 min. The lag period was not due to slow uptake of galactosamine by the cultured cells, since cellular UTP levels fell to less than 10% of controls within 60 min, a time frame comparable to that observed in vivo. Neither was the lag period a result of interference with cellular uptake of methionine or with conversion of methionine to cysteine, since the phenomenon was observed regardless of whether methionine or cysteine was used to promote glutathione resynthesis. Addition of uridine, which protects against galactosamine hepatotoxicity in vivo by replenishing hepatic UTP levels, did not prevent the suppression of glutathione resynthesis. The data indicate that (a) galactosamine inhibits the time-dependent resynthesis of glutathione in primary hepatocyte cultures, (b) a lag period exists for this response, and (c) this effect is not directly related to depletion of cellular UTP stores.

Animals↗
PubMed1976

Biochemical changes after hepatic injury from toxic doses of acetaminophen or furosemide.

The effects of hepatotoxic doses of acetaminophen and furosemide on the function and composition of hepatic endoplasmic reticulum were compared from 3 to 24 h after administration. Acetaminophen caused a significant decrease in microsomal protein concentration as early as 3 h after its administration, but furosemide did not affect the microsomal protein concentration until 24 h after the dose. Both acetaminophen and furosemide decreased the concentrations of cytochrome P-450 and cytochrome b5 in microsomes, and the activity of microsomal ethylmorphine N-demethylase and aniline hydroxylase. Glucose-6-phosphatase and UDP-glucuronyl transferase were not significantly affected by acetaminophen or furosemide administration, and neither diene conjugation nor hepatic triglycerides were increased. Incorporation of 3H-L-leucine into liver proteins was decreased by 50% after the administration of either acetaminophen or furosemide.

Acetaminophen↗
PubMed1976

Metabolic activation of furosemide to a chemically reactive, hepatotoxic metabolite.

The possibility that furosemide-induced hepatic necrosis results from the formation of a chemically reactive hepatotoxic metabolite has been examined. Hepatotoxic doses of 3H-furosemide or 14C-furosemide were administered to normal mice and to mice pretreated with piperonyl butoxide, cobalt chloride, alpha-naphthylisothiocyanate or phenobarbital. Mice were killed at various time intervals and tissues were examined for necrosis, for free furosemide concentrations and for covalently bound metabolites of furosemide. Little furosemide was covalently bound to muscle, whereas the amount of covalently bound material in liver usually paralleled the severity of live necrosis after alteration by the pretreatments. The severity of hepatic necrosis failed to correlate with furosemide concentrations in liver or plasma. Furosemide was shown to be metabolically activated to an arylating intermediate by a cytochrome P-450 mixed function oxidase in hepatic microsomes. Additional experiments demonstrated that the furan ring of furosemide was the portion activated.

Alanine Transaminase↗
PubMed1975

Acetylation rates and monthly liver function tests during one year of isoniazid preventive therapy.

A blind, prospective evaluation of the incidence and course of isoniazid-associated liver injury was made in 358 hospitalized men. The men were psychiatric patients during one year of tuberculosis preventive therapy. Blood samples were obtained at monthly intervals from the patients, the majority of whom were taking isoniazid. When the data were analyzed at the end of the year, a strikingly increased incidence of abnormal serum transaminase (SGOT) and bilirubin values was found among the isoniazid recipients. However, most subjects demonstrating biochemical evidence of hepatic injury recovered completely while continuing to take isoniazid and did not progress to clinically overt hepatitis. The mechanism underlying this adaptation to isoniazid injury is unknown. No serum antibodies against isoniazid could be demonstrated, and no correlation was found between the presence of antinuclear antibodies or elevated isoniazid plasma concentrations and the occurrence of hepatic injury. These data support the view that hepatotoxic metabolities of isoniazid may be responsible for the liver injury.

Acetylation↗