title: Lipid changes in hepatic microsomes and its relationship to P-nitrophenol glucuronidation in an experimental model of portal hypertension.
abstract: The liver is responsible for the most important metabolic pathway of non polar compounds. The aim of the present work was to study the p-nitrophenol glucuronidation and its relationship with lipidic composition of microsomal membrane in a model of hepatic portal hypertension and hepatocellular damage induced by monocrotaline. A global increment in liver microsomal phospholipids as well as changes in the phospholipid pattern (phosphatidylethanolamine and sphingomyelin increased up to 156 +/- 13 and 195 +/- 14% respectively) were detected in monocrotaline intoxicated rats when it were compared to control rats. The microsomal cholesterol content showed a decrease in monocrotaline intoxicated rats. (4.1 +/- 0.7 against 6.6 +/- 1.5 micrograms/mg of microsomal protein, in control rats). When p-nitrophenol activity was measured, Km from monocrotaline intoxicated rats was 0.137 mM, and Vmax was 2.9 nmol of p-nitrophenol/mg microsomal protein since in control group Km was 0.322 mM, and Vmax was 4.5 nmol of p-nitrophenol/mg microsomal protein. It is concluded that monocrotaline intoxicated rats showed a different behavior in the kinetics of p-nitrophenol UDP-glucuronyltransferase, as well as a different microsomal lipidic profile, when compared to control group.
authors.affiliation: Catedra de Fisiopatologia y Farmacologia, Facultad de Farmacia y Bioquimica, Universidad de Buenos Aires, Argentina.
authors.forename: C
authors.initials: C
authors.lastname: Ghanem
authors.forename: C
authors.initials: C
authors.lastname: Ghisolfi
authors.forename: L
authors.initials: L
authors.lastname: Marabotto
authors.forename: G
authors.initials: G
authors.lastname: Ouviña
authors.forename: M
authors.initials: M
authors.lastname: Rubio
authors.forename: J
authors.initials: J
authors.lastname: Perazzo
authors.forename: A
authors.initials: A
authors.lastname: Lemberg
authors.forename: L
authors.initials: L
authors.lastname: Bengochea
mesh_terms: D000818:Animals; D002784:Cholesterol / Q000378:metabolism; D005965:Glucuronates / Q000378:metabolism*; D014453:Glucuronosyltransferase / Q000378:metabolism; D006975:Hypertension, Portal / Q000378:metabolism*; D008658:Inactivation, Metabolic / Q000502:physiology*; D050356:Lipid Metabolism; D008297:Male; D008862:Microsomes, Liver / Q000378:metabolism*; D016686:Monocrotaline / Q000633:toxicity; D009596:Nitrophenols / Q000378:metabolism*; D010743:Phospholipids / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar
chemical_list: D005965:Glucuronates; D009596:Nitrophenols; D010743:Phospholipids; D016686:Monocrotaline; D002784:Cholesterol; D014453:Glucuronosyltransferase; C024836:4-nitrophenol