Morphologic effects of sulfur-substituted fatty acids on rat hepatocytes with special reference to proliferation of peroxisomes and mitochondria.
The morphologic effects of different sulfur-substituted mono- and dicarboxylic fatty acids on rat hepatocytes have been examined. The substance 1,10-biscarboxymethylthiodecane (BCMTD) is blocked for both beta- and omega-oxidation, whereas 1-monocarboxymethylthiodecane (CMTTD) is only non-beta-oxidizable. At equimolar doses BCMTD was considerably more potent than CMTTD in hypertrophic liver enlargement. At the ultrastructural level, BCMTD increased the volume fraction of the peroxisomes by a factor of 8, and their size and number by factors of 2.1 and 6.4, respectively. Furthermore, the frequency of dense cores in the peroxisomes decreased from 60 to 8%. CMTTD resulted in an increased volume fraction of peroxisomes (4.5-fold), in the mean volume (1.9-fold), and in the number of peroxisomes (3.7-fold). At the mitochondrial level, a gradual development toward megamitochondria was observed after CMTTD administration. BCMTD, however, increased the number of mitochondria but they tended to be smaller. Administration of both acids increased peroxisomal beta-oxidation and mitochondrial carnitine palmitoyltransferase activity, whereas the lipid content of hepatocytes was reduced with increasing doses of CMTTD and especially BCMTD. The acid 1-mono(carboxyethylthio)tetradecane (CETTD), which is able to undergo one cycle of beta-oxidation, caused no change in liver weight, and only marginal effects on peroxisomes and mitochondria were observed. In contrast to the BCMTD and CMTTD feeding, the animals developed a tremendous accumulation of fat in the livers: the volume fraction of lipid droplets increased 23-fold after CETTD feeding.
Kryvi
H
H
Zoological Laboratory, University of Bergen, Norway.
Aarsland
A
A
Berge
R K
RK
D000818:Animals; D002334:Carnitine O-Palmitoyltransferase / Q000378:metabolism; D003998:Dicarboxylic Acids / Q000378:metabolism*; D008099:Liver / Q000166:cytology* / Q000378:metabolism; D008297:Male; D008830:Microbodies / Q000378:metabolism / Q000648:ultrastructure*; D008854:Microscopy, Electron; D008930:Mitochondria, Liver / Q000201:enzymology / Q000378:metabolism / Q000648:ultrastructure*; D010084:Oxidation-Reduction; D011422:Propionates / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D013440:Sulfides / Q000378:metabolism*
D003998:Dicarboxylic Acids; D011422:Propionates; D013440:Sulfides; C062077:1-(carboxyethylthio)tetradecane; C062079:1,10-bis(carboxymethylthiodecane); C062078:1-(carboxymethylthio)tetradecane; D002334:Carnitine O-Palmitoyltransferase