Search PubMed⌕ Search

Biomedical subjects

S Z Cagen

Publications and source records attributed to S Z Cagen.

17 recordsLinked to original sources
PubMed1979

Effect of polybrominated biphenyls on the development of hepatic excretory function.

Polybrominated biphenyls (PBBs) stimulate hepatic drug metabolism in adult and developing rats. The purpose of this investigation was to determine the influence of PBBs on the development of the liver as an organ for chemical excretion. Exposure of developing rats to polybrominated biphenyls (PBBs) by feeding 50 ppm of PBBs to pregnant or lactating mothers and rat weanlings did not produce overt toxicity when compared to controls over a 49-day postnatal period. However, prenatal and postnatal dietary exposure to PBBs resulted in elevated liver weight. In 15-day-old rats, increased liver weight after PBBs was correlated with enhanced ouabain transport from plasma into bile. Liver weight was also elevated in 21-, 35- and 49-day-old rats treated with PBBs, but this effect was not associated with stimulation of ouabain transport in these animals. Stimulation of ouabain transport after PBBs in 15-day-old rats was associated with increased hepatic uptake of ouabain. Stimulation in 15-day-old rats and not older rats may be attributed to the relative importance of uptake for ouabain transport in 15-day-old rats.

Aging↗
PubMed1979

Characteristics of hepatic excretory function during development.

The purpose of this investigation was to characterize the development of hepatic excretory function in rats. Cumulative (40 min) intestinal ouabain content was lower and plasma ouabain concentrations were higher in 15-day-old rats than in 21-, 25-, 35- and 45-day-old animals and reached adult levels when rats were 35 days old. Impaired transport of ouabain in rat neonates correlated to low initial ouabain concentration in liver, which suggested that the inability of young rats to accumulate ouabain in liver may be the most important determinant for functional insufficiency. Bile duct ligation and bile salt infusion, treatments that primarily depress and enhance (respectively) excretion of sulfobromophthalein from liver into bile, markedly altered the disappearance of sulfobromophthalein from plasma of adult rats but did not appreciably affect sulfobromophthalein disappearance from blood of 15-day-old rats. The effect of bile duct ligation on ouabain transport in 15-day-old rats was also not as dramatic as the effect produced in adult rats. Hepatic uptake is rapid in adult rats and overall excretion is limited by a slower rate of transport from liver into bile. The lower rate of uptake in 15-day-old rats may limit overall transport function in young animals.

Aging↗
PubMed1978

Effect of polybrominated biphenyls on hepatic excretory function in rats and mice.

The purpose of this investigation was to determine the influence of polybrominated biphenyls (PBBs) on hepatic excretory function in developing and adult rats and mice. Prenatal or postnatal dietary exposure to PBBs (50 ppm in diet of pregnant or lactating mother or in diet of rat weanlings) resulted in elevated liver weight in developing rats. In 15-day-old rats that had been treated with PBBs increased liver weight correlated to enhanced ouabain transport from plasma into bile. Liver weight was also elevated in 21, 35, and 49-day-old rats exposed to PBBs, but this effect was not associated with stimulation of ouabain transport in these animals. However, adult rats fed 100 ppm PBBs for two weeks had significantly lower plasma concentrations of sulfobromophthalein (BSP) and increased biliary excretion of BSP, when compared to controls. PBBs-fed adult rats also excreted a greater percentage conjugated BSP (BSP-GSH) into bile. Two week dietary treatment of 100, 150, and 200 ppm PBBs resulted in enhanced initial disappearance of indocyanine green (ICG) from plasma of adult mice. However, dietary doses of 100 and 200 ppm PBBs to adult mice was not associated with enhanced capacity for ouabain excretion. In contrast, treatment with PBBs through the mother's diet (50 ppm) resulted in an almost twofold increase in cumulative ouabain excretion in 15-day-old mice. The results suggest that PBBs stimulate hepatic drug elimination in rats and mice, but the magnitude of the effect is dependent on age and transported compound.

Age Factors↗
PubMed1978

Distribution of polybrominated biphenyls after dietary exposure in pregnant and lactating rats and their offspring.

Female rats were fed PBBs in the diet (50 ppm) from day 8 of gestation to day 21 of gestation, from day 1 postpartum to day 14 postpartum or from day 8 of gestation through day 14 postpartum. Levels of PBBs were measured in various tissues. Small concentrations of PBBs (less than 5 microgram/g) were found in the brain, heart, lung, liver, small intestine, placenta, and gravid uterus. Larger concentrations (less than 30 microgram/g) were found in kidneys, the nongravid uterus, skin, mammary tissue, and fat. Lactation did not significantly alter the concentrations of PBBs found in tissues other than mammary tissue. Offspring were subjected to several exposure regimens by cross-fostering. Concentrations of PBBs in the neonatal livers were higher than in the adults nursing them. Transfer of PBBs via the milk appears to be much more important to appearance of PBBs in newborns than does placental transfer.

Animal Feed↗
PubMed1976

Effect of paraquat (methyl viologen) on liver function in mice.

Paraquat poisoning may result in pulmonary damage and hepatotoxicity. To examine the effect of paraquat on liver function, paraquat-treated mice were injected with sulfobromophthalein (BSP, 100 mg/kg) or indocyanine green (20 mg/kg) via the tail vein and plasma concentrations of these compounds were determined at various times. Hepatic concentrations of reduced glutathione were also determined following paraquat. Retention of BSP and indocyanine green in the plasma was observed 24 hours after paraquat. Body temperature of the poisoned mice was significantly depressed 24 hours after treatment and the paraquat-induced indocyanine green retention could be reversed by warming the paraquat-treated mice to normal body temperature. In contrast, paraquat-induced BSP retention was independent of body temperature. Inasmuch as hepatic glutathione concentrations were reduced 24 hours after paraquat treatment, the retention of BSP in the plasma may have been secondary to the reduction of hepatic glutathione concentrations.

Animals↗