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D L Roerig

Publications and source records attributed to D L Roerig.

74 records · Page 5Linked to original sources

Influence of temperature and plasma protein on doxorubicin uptake by isolated lungs.

To examine the influence of hyperthermia and plasma albumin binding on doxorubicin uptake by the isolated perfused lung, and on some indices of the physiologic stability of the lung, rabbit lungs were perfused in a recirculating system with a physiologic salt solution containing either 5% bovine serum albumin or 5% dextran, and uptake of doxorubicin from the perfusate into the lungs was studied at 36 degrees C and 43 degrees C. The rate of doxorubicin uptake by the lung was approximately doubled by increasing the lung temperature from 36 degrees C to 43 degrees C. The impact of albumin binding on the doxorubicin uptake was mainly to decrease the tissue to perfusate concentration ratio at equilibrium. Perfusion pressure, lung compliance, lung weight, and glutathione efflux were measured as indicators of the status of the perfused lungs during the perfusion period. In general, the changes in these variables indicate that the deterioration with time was greater at 43 degrees C than at 36 degrees C, regardless of the perfusate composition, and that at 36 degrees C the lungs were more stable when albumin was present in the perfusate.

Animals↗

Effect of methadone dose on the biliary excretion of methadone metabolites in the rat.

The effect of three different doses of 14C-methadone (0.08, 1.0 and 2.5 mg/kg) on the biliary excretion of methadone metabolites was studied in the rat. After administration of the 0.08- and 1.0-mg/kg doses of 14C-methadone there was no difference in the percentage of administered 14C excreted into bile with time. However, after the 2.5-mg/kg dose a significant increase was observed in the percentage of administered 14C excreted into bile. Analysis of bile samples showed that this increase was due to increases in the biliary excretion of two of the major metabolites of methadone. Several mechanisms could be responsible for this disproportionate increase in biliary excretion of methadone metabolites after high doses of methadone. It was found that the effect of high methadone dose on the biliary excretion of its metabolites was nearly eliminated when studied in phenobarbital (PB)-pretreated rats. Pretreatment of rats with PB increases the biliary excretion of methadone metabolites, primarily by increasing rates of methadone metabolism. The lack of additivity of the effect of the high dose of methadone and PB pretreatment on the biliary excretion of methadone metabolites suggests that a high dose of methadone also stimulates methadone metabolism, which results in the observed increased percentage of the administered dose excreted into bile.

Animals↗