title: Scanning electron microscopic analysis of intramyocellular lipid droplets in an animal model of type 2 diabetes.
abstract: OBJECTIVE
  To evaluate the accumulation pattern of intramyocellular lipids (IMCLs) in striated muscle during the development and progression of diabetes, using a novel scanning electron microscopic method.
  
  
  METHODS
  Hyperglycemia was induced by feeding diabetes-prone (DP) Psammomys obesus a high-energy (HE) diet. Lipid accumulation within gastrocnemius muscle fibers was assessed in formalin-fixed muscle samples during the development of hyperglycemia using high resolution imaging in a scanning electron microscope. We evaluated the temporal relationship between changes in IMCL quantity and morphology and the altered glucose metabolism and assessed the effect of reversal of hyperglycemia on IMCL level and morphology. Diabetes-resistant (DR) P. obesus served as controls.
  
  
  RESULTS
  Lipid accumulation in the muscle fibers of DP animals was increased with the development of hyperglycemia. This was characterized by increased lipid density as well as by an abundance of large lipid droplets. Reversal of the phenotype resulted in the disappearance of large lipid droplets. The IMCL level and the distribution of lipid droplet size were similar in muscles of both the normoglycemic DR and DP animals, with an abundance of small lipid droplets. This profile was changed following a HE diet only in the DP animals.
  
  
  CONCLUSIONS
  Lipid accumulation in the muscle of P. obesus during the development of hyperglycemia is characterized by increased quantity and accumulation of large lipid droplets. These changes were reversible upon normalization of blood glucose. The evaluated methodology is a useful tool for the study of the dynamics of lipid accumulation in different metabolic conditions.
authors.affiliation: Endocrinology and Metabolism Service, Department of Internal Medicine, Hadassah-Hebrew University Medical Center, Jerusalem, Israel.
authors.forename: Merav
authors.initials: M
authors.lastname: Fraenkel
authors.forename: Ram
authors.initials: R
authors.lastname: Weiss
authors.forename: Ilit
authors.initials: I
authors.lastname: Leizerman
authors.forename: Debbie
authors.initials: D
authors.lastname: Anaby
authors.forename: Eliahu
authors.initials: E
authors.lastname: Golomb
authors.forename: Gil
authors.initials: G
authors.lastname: Leibowitz
authors.forename: Nurit
authors.initials: N
authors.lastname: Kaiser
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D003924:Diabetes Mellitus, Type 2 / Q000378:metabolism / Q000473:pathology*; D004195:Disease Models, Animal; D018450:Disease Progression; D002149:Energy Intake; D005849:Gerbillinae; D006943:Hyperglycemia / Q000378:metabolism / Q000473:pathology*; D007328:Insulin / Q000097:blood; D050356:Lipid Metabolism; D008297:Male; D008855:Microscopy, Electron, Scanning; D018485:Muscle Fibers, Skeletal / Q000378:metabolism / Q000648:ultrastructure*; D018482:Muscle, Skeletal / Q000378:metabolism / Q000648:ultrastructure*; D010641:Phenotype; D013997:Time Factors
chemical_list: D001786:Blood Glucose; D007328:Insulin