Biomaterial Database

Calcium-related changes in the ultrastructure of mammalian myocardium. 1979

P K Singal, and M P Matsukubo, and N S Dhalla

Isolated rat hearts, perfused with Ca2+-free medium for 5 min, were perfusion-fixed for ultrastructural studies. Increased pinocytotoic activity and characteristic changes in the staining of the intercalated disc coupled with conspicuous staining of the middle lamina in the tight junctions in these hearts indicated an alteration in the sarcolemmal activity as well as cell--cell relationship. The intracellular effects of Ca2+-free perfusion were indicated by the presence of an active Golgi body as well as the loss of heterogenic staining of the nucleoplasm. The latter appears to be a direct consequence of Ca2+ depletion of the cell, as heterogeneity reappeared upon reintroduction of the calcium in the perfusion medium. The extent of structural damage upon reintroduction of calcium was dependent upon the extracellular calcium concentration. These observations suggest that perfusion with Ca2+-free medium causes some membrane changes in the heart which probably make it more vulnerable to the reintroduction of calcium. Furthermore, the structural damage observed upon reintroduction of calcium appeared to be related to the amount of calcium overload.

UI	MeSH Term	Description	Entries
D007365	Intercellular Junctions	Direct contact of a cell with a neighboring cell. Most such junctions are too small to be resolved by light microscopy, but they can be visualized by conventional or freeze-fracture electron microscopy, both of which show that the interacting CELL MEMBRANE and often the underlying CYTOPLASM and the intervening EXTRACELLULAR SPACE are highly specialized in these regions. (From Alberts et al., Molecular Biology of the Cell, 2d ed, p792)	Cell Junctions,Cell Junction,Intercellular Junction,Junction, Cell,Junction, Intercellular,Junctions, Cell,Junctions, Intercellular
D008297	Male		Males
D008854	Microscopy, Electron	Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.	Electron Microscopy
D008933	Mitochondrial Swelling	An increase in MITOCHONDRIAL VOLUME due to an influx of fluid; it occurs in hypotonic solutions due to osmotic pressure and in isotonic solutions as a result of altered permeability of the membranes of respiring mitochondria.	Giant Mitochondria,Megamitochondria,Mitochondrial Hypertrophy,Giant Mitochondrias,Hypertrophy, Mitochondrial,Megamitochondrias,Mitochondria, Giant,Mitochondrial Hypertrophies,Swelling, Mitochondrial
D009206	Myocardium	The muscle tissue of the HEART. It is composed of striated, involuntary muscle cells (MYOCYTES, CARDIAC) connected to form the contractile pump to generate blood flow.	Muscle, Cardiac,Muscle, Heart,Cardiac Muscle,Myocardia,Cardiac Muscles,Heart Muscle,Heart Muscles,Muscles, Cardiac,Muscles, Heart
D010477	Perfusion	Treatment process involving the injection of fluid into an organ or tissue.	Perfusions
D002118	Calcium	A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.	Coagulation Factor IV,Factor IV,Blood Coagulation Factor IV,Calcium-40,Calcium 40,Factor IV, Coagulation
D006056	Golgi Apparatus	A stack of flattened vesicles that functions in posttranslational processing and sorting of proteins, receiving them from the rough ENDOPLASMIC RETICULUM and directing them to secretory vesicles, LYSOSOMES, or the CELL MEMBRANE. The movement of proteins takes place by transfer vesicles that bud off from the rough endoplasmic reticulum or Golgi apparatus and fuse with the Golgi, lysosomes or cell membrane. (From Glick, Glossary of Biochemistry and Molecular Biology, 1990)	Golgi Complex,Apparatus, Golgi,Complex, Golgi
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D051381	Rats	The common name for the genus Rattus.	Rattus,Rats, Laboratory,Rats, Norway,Rattus norvegicus,Laboratory Rat,Laboratory Rats,Norway Rat,Norway Rats,Rat,Rat, Laboratory,Rat, Norway,norvegicus, Rattus