Effects of psychotropic drugs on aldo-keto reductase activity in rat ovary and adrenal gland

Gender differences and pregnant women in a methadone maintenance treatment (MMT) clinic

We prospectively compared gender outcome among 470 MMT patients admitted between June 1993 and Dec 2002. Urine samples were analyzed for drug abuse after one month and after one year. On admission females 131(27.9%) were significantly younger (34.5 +/-7.5 years) than males 339(72.1%) (37.3 +/- 8.3 years) (ANOVA; F = 11, p = 0.001) and had significantly higher cocaine abuse (20% vs. 11.3%) (Fisher's Exact Test, p = 0.02). After one year, groups had: (a) similar retention in treatment (76.3%-females, 72.6%-males), (b) stop in opiate abuse (65%-females, 65.3%-males), (c) a net decrease in cocaine abuse (% positive that became negative minus % negative that became positive) (68.0%-females, 51.6%-males). Females who were admitted to treatment while pregnant (n = 45) were significantly younger (31.5 +/-5.4 years) compared to 86 non-pregnant (36.1 +/- 7.9, ANOVA F = 12.1, p = 0.001). We concluded that compared to males, females started MMT younger and had a higher proportion of cocaine abuse even though females' outcome were similar to males'.

Inhibition of aldo-keto reductases by phenobarbital alters metabolism, pharmacokinetics and toxicity of doxorubicin in rats

Doxorubicin is an effective anticancer agent that is limited by numerous adverse effects, cardiotoxicity causing the most concern. Its alcohol metabolite, doxorubicinol, and free radicals have been implicated in the aetiology of this toxicity. This study was based on the premise that inhibition of aldo-keto reductases would improve the efficacy of doxorubicin by reducing its toxic metabolites and modifying its pharmacokinetics. We assessed the effect of in-vitro inhibition of aldo-keto reductases on the metabolism of doxorubicin in cytosolic fractions of heart and liver of rats in the presence of Na-phenobarbital. The inhibition was confirmed by a significant reduction in the formation of doxorubicinol. The results of the in-vitro study were further evaluated in-vivo. The concentrations of doxorubicin in plasma, bile and urine and its major metabolites in bile and urine were measured in Na-phenobarbital-pretreated rats. Each rat received 100 mg kg(-1)/day intraperitoneal injection of sodium phenobarbital for three days followed by a single intravenous dose of 10 mg kg(-1) [14C-14]doxorubicin (sp. act. 0.2 microCi mg(-1)) on the fourth day. The levels of drug in all biological samples were measured by HPLC. The pretreatment resulted in an increase in biological half-life (5.8 +/- 1.5 vs 3.7 +/- 0.93 h control group, P < 0.05) and area under plasma concentration-time curve (19.6 +/- 1.7 vs 14.65 +/- 1.68 mg h L(-1) control group, P < 0.05). The cumulative amount of doxorubicinol in the bile and urine of pretreated animals was reduced significantly. In terms of % dose, the amount in the bile declined from 4.2 +/- 0.8% in control to 2.4 +/- 0.3% and in urine from 0.18 +/- 0.08% to 0.12 +/- 0.07%. There were no significant changes in doxorubicin aglycone and doxorubicinol aglycone. Serum creatine kinase levels were measured as a biomarker of damage to cardiac muscle. The area under creatine kinase level-time curve was reduced by approximately 50% in phenobarbital-pretreated animals. The results indicate that the inhibition of aldo-keto reductase could provide a useful approach to improve the safety of doxorubicin by reducing its alcohol metabolite. Furthermore, if the reduction in the area under the serum creatine kinase-time curve represents a reduced damage to heart muscle, it can be concluded that doxorubicinol plays an important role in this injury.