title: Cyclosporine-induced changes in drug metabolizing enzymes in hyperlipemic rabbit kidneys could explain its toxicity.
abstract: This study investigates the mechanism of cyclosporine A (CsA)-mediated nephrotoxicity by examining the hypothesis that CsA toxicity is mediated through its effect on the kidney drug metabolizing enzymes in a hyperlipemic rabbit model. Twenty-four female New Zealand white rabbits divided into four groups. Group 1 received regular diet. Group 2 received 1% cholesterol diet. Group 3 received CsA (25&#x2009;mg/kg, orally once daily) and group 4 received 1% cholesterol diet and CsA (25&#x2009;mg/kg, orally once daily). Cytochrome P450 2E1 (CYP2E1) activity in kidney microsomes was assessed by measuring p-nitrophenol hydroxylase activity. Generation of reactive oxygen species (ROS) was assessed by measuring malondialdehyde (MDA) and the protein carbonyl. Effect of CsA and hyperlipidemia on the antioxidant proteins were also assessed using standard techniques. CsA but not the high-cholesterol diet induced significant elevation in MDA, protein carbonyl and CYP2E1 activities in the kidney. The addition of cholesterol to CsA normalized ROS markers without affecting the CsA-enhanced CYP2E1 activity. Alone, CsA caused characteristic tubular injury, whereas the addition of high-cholesterol diet to CsA nearly abolished the tubular damage. CsA-enhanced rabbit kidney ROS and CYP2E1 activities. Hyperlipidemia attenuates CsA tubular injury, most probably due to normalization of renal ROS, but not CYP2E1 activity.
authors.affiliation: School of Pharmacy, Pacific University Oregon, Hillsboro, OR, USA.
authors.forename: Fawzy
authors.initials: F
authors.lastname: Elbarbry
authors.forename: Ahmed
authors.initials: A
authors.lastname: Ragheb
authors.forename: Ahmed
authors.initials: A
authors.lastname: Attia
authors.forename: Rajni
authors.initials: R
authors.lastname: Chibbar
authors.forename: Travis
authors.initials: T
authors.lastname: Marfleet
authors.forename: Ahmed
authors.initials: A
authors.lastname: Shoker
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D002791:Cholesterol, Dietary / Q000009:adverse effects; D003404:Creatinine / Q000097:blood; D016572:Cyclosporine / Q000633:toxicity*; D019392:Cytochrome P-450 CYP2E1 / Q000378:metabolism; D005260:Female; D005978:Glutathione / Q000378:metabolism; D006949:Hyperlipidemias / Q000150:complications / Q000378:metabolism*; D007166:Immunosuppressive Agents / Q000633:toxicity*; D007668:Kidney / Q000187:drug effects* / Q000201:enzymology / Q000473:pathology; D007674:Kidney Diseases / Q000139:chemically induced / Q000150:complications / Q000473:pathology; D015227:Lipid Peroxidation / Q000187:drug effects; D008055:Lipids / Q000097:blood; D018384:Oxidative Stress / Q000187:drug effects; D011817:Rabbits; D017382:Reactive Oxygen Species / Q000378:metabolism*; D014508:Urea / Q000097:blood
chemical_list: D000975:Antioxidants; D002791:Cholesterol, Dietary; D007166:Immunosuppressive Agents; D008055:Lipids; D017382:Reactive Oxygen Species; D016572:Cyclosporine; D014508:Urea; D003404:Creatinine; D019392:Cytochrome P-450 CYP2E1; D005978:Glutathione