Biomaterial Database

Transient appearance of vacuoles in fatigued Xenopus muscle fibres. 1990

J Lännergren, and H Westerblad, and B Flock

Department of Physiology II, Karolinska Institutet, Stockholm, Sweden.

In the preceding paper we showed that post-contractile depression is accompanied by an increased light scattering in the light microscope, which suggests an association between morphological changes and the force reduction. In the present paper the morphology of fatigued fibres has been studied using electron microscopical techniques. Fibres fixed in glutaraldehyde during maximum post-contractile depression (about 20 min after fatiguing stimulation) contained a large number of vacuoles. Fibres fixed earlier displayed generally swollen and in some cases vesiculated mitochondria, but only a few vacuoles. Fixation methods aiming at visualizing the T-tubular system revealed apparent communications between T-tubules and vacuoles; apart from this the T-tubular system, as well as the triadic junctions, appeared to be normal. We consider it most likely that the vacuoles primarily originate from damaged mitochondria, but other possibilities cannot be excluded. Further, a simple causal relation between the observed ultrastructural changes and the force depression is not obvious. Rather we suggest that post-contractile depression is caused by additional changes in the triadic junctions, which were not detected with the present techniques.

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
D008931	Mitochondria, Muscle	Mitochondria of skeletal and smooth muscle. It does not include myocardial mitochondria for which MITOCHONDRIA, HEART is available.	Sarcosomes,Mitochondrion, Muscle,Muscle Mitochondria,Muscle Mitochondrion,Sarcosome
D009119	Muscle Contraction	A process leading to shortening and/or development of tension in muscle tissue. Muscle contraction occurs by a sliding filament mechanism whereby actin filaments slide inward among the myosin filaments.	Inotropism,Muscular Contraction,Contraction, Muscle,Contraction, Muscular,Contractions, Muscle,Contractions, Muscular,Inotropisms,Muscle Contractions,Muscular Contractions
D009132	Muscles	Contractile tissue that produces movement in animals.	Muscle Tissue,Muscle,Muscle Tissues,Tissue, Muscle,Tissues, Muscle
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
D014617	Vacuoles	Any spaces or cavities within a cell. They may function in digestion, storage, secretion, or excretion.	Vacuole
D014982	Xenopus laevis	The commonest and widest ranging species of the clawed "frog" (Xenopus) in Africa. This species is used extensively in research. There is now a significant population in California derived from escaped laboratory animals.	Platanna,X. laevis,Platannas,X. laevi
D066298	In Vitro Techniques	Methods to study reactions or processes taking place in an artificial environment outside the living organism.	In Vitro Test,In Vitro Testing,In Vitro Tests,In Vitro as Topic,In Vitro,In Vitro Technique,In Vitro Testings,Technique, In Vitro,Techniques, In Vitro,Test, In Vitro,Testing, In Vitro,Testings, In Vitro,Tests, In Vitro,Vitro Testing, In