Hepatic plasma membranes from genetically obese (ob/ob) mice: studies on fluorescence polarization, phospholipid composition and 5'-nucleotidase activity.
Hepatic plasma membrane lipids of lean (+/?) and obese (ob/ob) mice have been investigated using 1,6-diphenylhexatriene (DPH). Arrhenius plots of DPH fluorescence polarization in membranes showed the breakpoint in obese mice was reduced from 21 to 15 degrees C, whereas the breakpoint of 5'-nucleotidase activity was raised from 23 to 32 degrees C. Arrhenius break temperatures of DPH polarization and 5'-nucleotidase activity responded differently to housing mice at 34 degrees C and triiodothyronine (T3) treatment. Studies of DPH polarization in liposomes and phospholipid fatty acid composition suggested that differences in sphingomyelin acyl composition determine Arrhenius characteristics of hepatic 5'-nucleotidase in lean and obese mice.
D015720:5'-Nucleotidase; D000818:Animals; D001831:Body Temperature; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism*; D002784:Cholesterol / Q000378:metabolism; D004161:Diphenylhexatriene; D005227:Fatty Acids / Q000378:metabolism; D005454:Fluorescence Polarization; D008081:Liposomes; D008099:Liver / Q000378:metabolism*; D051379:Mice; D008820:Mice, Obese; D009708:Nucleotidases / Q000378:metabolism*; D010743:Phospholipids / Q000378:metabolism*; D014284:Triiodothyronine / Q000494:pharmacology
D005227:Fatty Acids; D008081:Liposomes; D010743:Phospholipids; D014284:Triiodothyronine; D004161:Diphenylhexatriene; D002784:Cholesterol; D009708:Nucleotidases; D015720:5'-Nucleotidase