Lipid droplets in the heart interstitium: concentration and distribution.
A morphological study of the sudanophilic lipids in dog and human hearts was carried out. The hearts of 5 mongrel dogs and 20 auricular appendices of human patients were utilized. The dog hearts were fixed in situ by perfusion with 2% glutaraldehyde, and the human tissue was fixed by immersion. For the ultrastructural study, some blocks of every portion of the specimen were postfixed in osmium and embedded in Epon. The topographical and quantitative study was done on frozen 20-mu sections of tissue stained with Sudan IV in propylene glycol and counterstained with hematein (Geigy). The results indicate that a significant quantity of visible triglycerides is extracellular and located in the interstitial spaces of the heart. The dimensions of these lipid droplets vary from 0.5 mu to more than 20 mu. The highest concentration was found in the epicardial region of the left ventricle, but a significant amount was found in the endocardium and in the middle portion of the myocardium. These observations indicate that a sizable portion of the heart interstitium is occupied by free droplets of triglycerides. This substrate pool is probably mobile and readily available as a source of energy.
D000273:Adipose Tissue / Q000166:cytology / Q000378:metabolism; D000818:Animals; D004285:Dogs; D004699:Endocardium / Q000378:metabolism; D005110:Extracellular Space / Q000378:metabolism; D006801:Humans; D050356:Lipid Metabolism; D009206:Myocardium / Q000378:metabolism* / Q000648:ultrastructure; D010496:Pericardium / Q000378:metabolism; D014280:Triglycerides / Q000378:metabolism
D014280:Triglycerides