title: Effects of glucose supplementation on the pharmacokinetics of intravenous chlorzoxazone in rats with water deprivation for 72 h.
abstract: It was reported that in rats with water deprivation for 72 h with food (dehydration rat model), the expression of CYP2E1 was 3-fold induced with an increase in mRNA level and glucose supplementation instead of food during 72-h water deprivation (dehydration rat model with glucose supplementation) inhibited the CYP2E1 induction in dehydration rat model. It was also reported that chlorzoxazone (CZX) is metabolized to 6-hydroxychlorzoxazone (OH-CZX) mainly via CYP2E1 in rats. Hence, the effects of glucose supplementation on the pharmacokinetics of CZX and OH-CZX were investigated after intravenous administration of CZX at a dose of 25 mg/kg to control male Sprague-Dawley rats and dehydration rat model and dehydration rat model with glucose supplementation. Based on the above mentioned results of CYP2E1, it could be expected that increased formation of OH-CZX in dehydration rat model could decrease in dehydration rat model with glucose supplementation. This was proven by the following results. In dehydration rat model with glucose supplementation, the AUC of OH-CZX was significantly smaller (1900 versus 1050 microg min/ml), AUC(OH-CZX)/AUC(CZX) ratio was considerably smaller (105 versus 34.3%), C(max) was significantly lower (20.6 versus 8.08 microg/ml), total amount excreted in 24-h urine as unchanged OH-CZX was significantly smaller (62.3 versus 42.7% of intravenous dose of CZX), and in vitro V(max) (2.18 versus 1.20 nmol/min/mg protein) and CL(int) (0.0285 versus 0.0171 ml/min/mg protein) were significantly slower than those in dehydration rat model.
authors.affiliation: College of Pharmacy, Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul, South Korea.
authors.forename: Yu Chul
authors.initials: YC
authors.lastname: Kim
authors.forename: Inchul
authors.initials: I
authors.lastname: Lee
authors.forename: Sang Geon
authors.initials: SG
authors.lastname: Kim
authors.forename: Seong-Hee
authors.initials: SH
authors.lastname: Ko
authors.forename: Myung Gull
authors.initials: MG
authors.lastname: Lee
authors.forename: So Hee
authors.initials: SH
authors.lastname: Kim
mesh_terms: D000818:Animals; D019540:Area Under Curve; D002753:Chlorzoxazone / Q000493:pharmacokinetics* / Q000494:pharmacology; D019392:Cytochrome P-450 CYP2E1 / Q000096:biosynthesis*; D003681:Dehydration / Q000201:enzymology*; D019587:Dietary Supplements; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D005947:Glucose / Q000494:pharmacology*; D007275:Injections, Intravenous / Q000379:methods; D008297:Male; D009125:Muscle Relaxants, Central / Q000493:pharmacokinetics* / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D014868:Water Deprivation
chemical_list: D009125:Muscle Relaxants, Central; D019392:Cytochrome P-450 CYP2E1; D002753:Chlorzoxazone; D005947:Glucose