The pathway of ketogenesis in rumen epithelium of the sheep.
A method for the fractionation of sheep rumen epithelium with limited mitochondrial breakage is described. The distributions of the enzymes of the 3-hydroxy-3-methylglutaryl-CoA pathway of ketogenesis indicate that this process is exclusively mitochondrial. Enzyme activities are sufficient to account for the ketogenic rates found in vivo. The failure of (-)-hydroxycitrate to block ketogenic flux supports this view. 3-Hydroxybutyrate dehydrogenase activity is largely associated with particulate material in the mitochondrial fraction. ATP citrate lyase activity was found, with appreciable acetoacetyl-CoA thiolase and 3-hydroxy-3-methylglutaryl-CoA synthase in the cytoplasmic fraction.
D000818:Animals; D002458:Cell Fractionation / Q000379:methods; D003593:Cytoplasm / Q000201:enzymology; D004848:Epithelium / Q000201:enzymology / Q000378:metabolism; D066298:In Vitro Techniques; D007657:Ketone Bodies / Q000096:biosynthesis*; D008928:Mitochondria / Q000201:enzymology; D012417:Rumen / Q000201:enzymology / Q000378:metabolism*; D012756:Sheep
D007657:Ketone Bodies