Biomaterial Database

A freeze-fracture study of fiber types in normal human muscle. 1979

S A Shafiq, and B Leung, and H S Schutta

The sarcoplasmic reticulum (SR) and plasma membranes of Type 1 and Type 2 fibers of normal human muscle were examined by the freeze-fracture technique. Total particle counts in the SR appeared much lower than in other mammals and a packing density of about 1200 particles/micrometer 2 was found in both longitudinal and cisternal components of SR. There was no difference in particle density of Type 1 and Type 2 fibers. In freeze-fracture replicas of plasma membranes several fiber type differences were seen. The surface caveolae were uniformly distributed in Type 1 fibers whereas in Type 2 they were clustered preferentially at the I-band levels. Total density of intramembranous particles was greater in Type 1 fibers (347 +/- 68/micrometer 2 in P-face, 58 +/- 11/micrometer 2 in E face) than in Type 2 fibers (207 +/- 30/micrometer 2 in P-face, 80 +/- 9/micrometer 2 in E-face). There was a striking difference in respect to rectilinear arrays which were virtually absent in Type 1 fibers (0--2/micrometer 2) and numberous (up to 50--70/micrometer 2) in Type 2 fibers.

UI	MeSH Term	Description	Entries
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
D009132	Muscles	Contractile tissue that produces movement in animals.	Muscle Tissue,Muscle,Muscle Tissues,Tissue, Muscle,Tissues, Muscle
D002462	Cell Membrane	The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.	Plasma Membrane,Cytoplasmic Membrane,Cell Membranes,Cytoplasmic Membranes,Membrane, Cell,Membrane, Cytoplasmic,Membrane, Plasma,Membranes, Cell,Membranes, Cytoplasmic,Membranes, Plasma,Plasma Membranes
D005614	Freeze Fracturing	Preparation for electron microscopy of minute replicas of exposed surfaces of the cell which have been ruptured in the frozen state. The specimen is frozen, then cleaved under high vacuum at the same temperature. The exposed surface is shadowed with carbon and platinum and coated with carbon to obtain a carbon replica.	Fracturing, Freeze,Fracturings, Freeze,Freeze Fracturings
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000293	Adolescent	A person 13 to 18 years of age.	Adolescence,Youth,Adolescents,Adolescents, Female,Adolescents, Male,Teenagers,Teens,Adolescent, Female,Adolescent, Male,Female Adolescent,Female Adolescents,Male Adolescent,Male Adolescents,Teen,Teenager,Youths
D000328	Adult	A person having attained full growth or maturity. Adults are of 19 through 44 years of age. For a person between 19 and 24 years of age, YOUNG ADULT is available.	Adults
D012519	Sarcoplasmic Reticulum	A network of tubules and sacs in the cytoplasm of SKELETAL MUSCLE FIBERS that assist with muscle contraction and relaxation by releasing and storing calcium ions.	Reticulum, Sarcoplasmic,Reticulums, Sarcoplasmic,Sarcoplasmic Reticulums