Muscular involvement in lysosomal acid lipase deficiency in rats.
We investigated the pathological and biochemical changes of skeletal muscle in rats with lysosomal acid lipase deficiency, which is an animal counterpart of human Wolman's disease. In the affected rats, the acid lipase activity for three different substrates, 4-methylumbelliferyl-oleate (18.9% of the normal control level), [14C]cholesteryl oleate (23.5%), and [14C]triolein (26.9%), was similarly decreased in the lysosomal fraction of skeletal muscle which was obtained by differential centrifugation. Histochemical studies showed that acid phosphatase activity was high in the endomysium and perimysium and in some muscle fibers. Some fibers showed vacuolar degeneration resembling "rimmed vacuoles". Ultrastructural studies demonstrated many membrane-bound lipid droplets in the muscle fibers, especially in the subsarcolemmal space, indicating that a low density lipoprotein (LDL) uptake pathway apparently existed in the muscle cells. However, such lipid accumulation was much greater in the interstitial cells and the endothelial cells. This distribution also suggests that LDL/cholesterol is supplied to muscle cells predominantly through endothelial cells.
Honda
Y
Y
Third Department of Internal Medicine, Kagoshima University School of Medicine, Japan.
Kuriyama
M
M
Higuchi
I
I
Fujiyama
J
J
Yoshida
H
H
Osame
M
M
D000818:Animals; D002250:Carbon Radioisotopes; D002401:Cathepsin B / Q000378:metabolism; D056668:Cathepsin L; D002403:Cathepsins / Q000378:metabolism; D002458:Cell Fractionation; D003546:Cysteine Endopeptidases; D004195:Disease Models, Animal; D010450:Endopeptidases; D006026:Glycoside Hydrolases / Q000378:metabolism; D008049:Lipase / Q000172:deficiency* / Q000378:metabolism; D016464:Lysosomal Storage Diseases / Q000201:enzymology / Q000473:pathology*; D008247:Lysosomes / Q000201:enzymology* / Q000648:ultrastructure; D009132:Muscles / Q000201:enzymology / Q000473:pathology* / Q000648:ultrastructure; D009829:Oleic Acids / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D013379:Substrate Specificity
D002250:Carbon Radioisotopes; D009829:Oleic Acids; D008049:Lipase; D006026:Glycoside Hydrolases; D002403:Cathepsins; D010450:Endopeptidases; D003546:Cysteine Endopeptidases; D002401:Cathepsin B; C534281:CTSL protein, human; D056668:Cathepsin L; C534280:Ctsl protein, rat