In vivo enrichment of hepatic microsomes with isotopic iron

1974 ◽  
Vol 60 (2) ◽  
pp. 462-468 ◽  
Author(s):  
Mark R. Montgomery ◽  
Richard R. Erickson ◽  
Jordan L. Holtzman
Keyword(s):  
Hepatic Microsomes

Alterations in the metabolism of 7,12-dimethylbenz[a]anthracene and various xenobiotics by rat hepatic microsomes following Sudan III treatment in vivo

1985 ◽  
Vol 6 (3) ◽  
pp. 469-472 ◽  
Author(s):  
John J. O'Dowd ◽  
Alan K. Burnett ◽  
Ainsley Weston ◽  
Neil J. Bulleid ◽  
John A. Craft
Keyword(s):  
Hepatic Microsomes ◽  
Sudan Iii

scholarly journals Phenobarbital influence on neuromuscular block produced by rocuronium in rats

2008 ◽  
Vol 23 (4) ◽  
pp. 343-347 ◽  
Author(s):  
Angélica de Fátima de Assunção Braga ◽  
Caroline Coutinho de Barcelos ◽  
Franklin Sarmento da Silva Braga ◽  
Samanta Cristina Antoniassi Fernandes ◽  
Yoko Oshima Franco ◽  
...  
Keyword(s):  
Cytochrome P450 ◽  
Neuromuscular Blockade ◽  
Neuromuscular Block ◽  
Cytochrome B5 ◽  
Muscle Response ◽  
In Vivo Experiments ◽  
Hepatic Microsomes ◽  
Enzymatic Induction

PURPOSE: To evaluate in vitro and in vivo neuromuscular blockade produced by rocuronium in rats treated with Phenobarbital and to determine cytochrome P450 and cytochrome b5 concentrations in hepatic microsomes. METHODS: Thirty rats were included in the study and distributed into 6 groups of 5 animals each. Rats were treated for seven days with phenobarbital (20 mg/kg) and the following parameters were evaluated: 1) the amplitude of muscle response in the preparation of rats exposed to phenobarbital; 2) rocuronium effect on rat preparation exposed or not to phenobarbital; 3) concentrations of cytochrome P450 and cytochrome b5 in hepatic microsomes isolated from rats exposed or not to phenobarbital. The concentration and dose of rocuronium used in vitro and in vivo experiments were 4 µg/mL and 0,6 mg/kg, respectively. RESULTS: Phenobarbital in vitro and in vivo did not alter the amplitude of muscle response. The neuromuscular blockade in vitro produced by rocuronium was significantly different (p=0.019) between exposed (20%) and not exposed (60%) rats; the blockade in vivo was significantly greater (p=0.0081) in treated rats (93.4%). The enzymatic concentrations were significantly greater in rats exposed to phenobarbital. CONCLUSIONS: Phenobarbital alone did not compromise neuromuscular transmission. It produced enzymatic induction, and neuromuscular blockade in vivo produced by rocuronium was potentiated by phenobarbital.

The In Vivo Effects of Oral Anticoagulants in Man: Comparison Between Liver and Non-Hepatic Tissues

1988 ◽  
Vol 59 (02) ◽  
pp. 147-150 ◽  
Author(s):  
Marian de Boer-van den Berg ◽  
Henk H W Thijssen ◽  
Cees Vermeer
Keyword(s):  
Vitamin K ◽  
Reductase Activity ◽  
Oral Anticoagulant Therapy ◽  
Oral Anticoagulants ◽  
Quinone Reductase ◽  
Hepatic Microsomes ◽  
Precursor Proteins ◽  
Epoxide Reductase ◽  
In Vivo Effects

SummaryThe in vivo effects of oral anticoagulant therapy with 4–hydroxycoumarins on various vitamin K–dependent enzyme systems in man were compared. In hepatic microsomes obtained from donors who has been treated with 4–hydroxycoumarins for more than 6 months, the vitamin K 2,3 epoxide reductase activity and the DTT–dependent vitamin K quinone reductase activity were diminished to 35% and 20% of the corresponding normal values. In the non–hepatic tissues, only a small decrease in vitamin K 2,3 epoxide reductase activity could be demonstrated, while no differences were found in the vitamin K quinone reductase activities. In none of the tissues a significant increase of non–carboxylated precursor proteins was observed, whereas also vitamin K hydroquinone–dependent carboxylase activities seemed to be unaffected by the anticoagulant treatment.

Spectrophotometric and radiometric studies on the in vivo binding of phenobarbital to hepatic microsomes

1976 ◽  
Vol 173 (2) ◽  
pp. 710-719 ◽  
Author(s):  
Jordan L. Holtzman ◽  
Barry H. Rumack ◽  
Richard R. Erickson
Keyword(s):  
In Vivo Binding ◽  
Hepatic Microsomes

scholarly journals Pharmacokinetic Interaction between Nevirapine and Nortriptyline in Rats: Inhibition of Nevirapine Metabolism by Nortriptyline

2014 ◽  
Vol 58 (12) ◽  
pp. 7041-7048 ◽  
Author(s):  
Iris Usach ◽  
Virginia Melis ◽  
Patricia Gandía ◽  
José-Esteban Peris
Keyword(s):  
Plasma Concentrations ◽  
Pharmacokinetic Interaction ◽  
Hepatic Metabolism ◽  
Transcriptase Inhibitor ◽  
Tricyclic Antidepressant ◽  
Pharmacokinetic Parameters ◽  
Maximum Plasma ◽  
Hepatic Microsomes

ABSTRACTOne of the most frequent comorbidities of HIV infection is depression, with a lifetime prevalence of 22 to 45%. Therefore, it was decided to study a potential pharmacokinetic interaction between the nonnucleoside reverse transcriptase inhibitor nevirapine (NVP) and the tricyclic antidepressant nortriptyline (NT). NVP and NT were administered to rats either orally, intraduodenally, or intravenously, and the changes in plasma levels and pharmacokinetic parameters were analyzed. Experiments with rat and human hepatic microsomes were carried out to evaluate the inhibitory effects of NT on NVP metabolism. NVP plasma concentrations were significantly higher when this drug was coadministered with NT. The maximum plasma concentrations of NVP were increased 2 to 5 times and the total plasma clearance was decreased 7-fold in the presence of NT. However, statistically significant differences in the pharmacokinetic parameters of NT in the absence and presence of NVP were not found.In vitrostudies with rat and human hepatic microsomes confirmed the inhibition of NVP hepatic metabolism by NT in a concentration-dependent way, with the inhibition being more intense in the case of rat microsomes. In conclusion, a pharmacokinetic interaction between NVP and NT was detected. This interaction was a consequence of the inhibition of hepatic metabolism of NVP by NT.In vivohuman studies are required to evaluate the effects of this interaction on the pharmacokinetics of NVP before it can be taken into account for patients receiving NVP.

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