title: Flow cytometric analysis of the effects of high protein diet on isolated rat liver mitochondria.
abstract: We have investigated changes that occur in mitochondria obtained from the livers of rats that had been maintained on a high protein diet (80% casein instead of 20%) for 6 months. Liver homogenates were separated by centrifugation into a mitochondrial fraction, a nuclear fraction and the supernatant fluid of the nuclear fraction (nuclear wash). Rhodamine-123 was used to selectively stain mitochondria depending upon their membrane potential. The stained organelles were processed through a flow cytometer where the fluorescent stains were excited by the 488 nm wavelength of a laser and the resultant fluorescence signals analysed. After 6 months on a high protein diet, mitochondria displayed an increase in the fluorescence associated with rhodamine-123 uptake in both mitochondrial and nuclear wash fractions, while mitochondrial fluorescence in the nuclear fraction showed a heterogeneous distribution. This was interpreted as an increase in membrane potential in most of the liver mitochondria under these nutritional conditions, with a certain degree of heterogeneity. These functional changes may be correlated with morphological alterations previously reported and show the usefulness of flow cytometry for biochemical analysis of isolated mitochondria.
authors.affiliation: Instituto de Investigaciones Citológicas de la Caja de Ahorros de Valencia, Spain.
authors.forename: J E
authors.initials: JE
authors.lastname: O'Connor
authors.forename: B F
authors.initials: BF
authors.lastname: Kimler
authors.forename: J L
authors.initials: JL
authors.lastname: Vargas
mesh_terms: D000818:Animals; D002458:Cell Fractionation; D004044:Dietary Proteins / Q000008:administration & dosage* / Q000494:pharmacology; D005434:Flow Cytometry; D008099:Liver / Q000166:cytology / Q000187:drug effects / Q000648:ultrastructure; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects; D008930:Mitochondria, Liver / Q000187:drug effects* / Q000502:physiology; D051381:Rats; D011919:Rats, Inbred Strains; D012235:Rhodamines
chemical_list: D004044:Dietary Proteins; D012235:Rhodamines