ISSN:
1432-0878
Keywords:
Muscle fibres (Tadpole tail)
;
Degeneration
;
Macrophages
;
Autophagic vacuoles
;
Ultrastructure
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Summary This report describes histochemical and ultrastructural studies of tail muscles in tadpoles of Rana japonica and Rana catesbeiana during metamorphosis, this process being accompanied by degeneration of the tail. Degeneration of individual tail muscles does not occur at the same time; this is true for both the red and white muscle fibres. The initial phase of degeneration showed mesenchymal macrophages first invading the muscle fibres and then sending out many long cytoplasmic processes which split the fibres apart. The disappearance of myofibrils during degeneration proceeds along at least two different mechanisms even within a single muscle fibre. In one type, the Z-band becomes diffuse and then disappears, resulting in fragmentation of the myofibrils at the sites previously occupied by the Z-bands. The second pattern of degeneration is characterized by disappearance of the Z-band followed by a fanning out of the myofilaments not associated with fragmentation of myofibrils. As atrophy of muscle fibres proceeds, acid phosphatase activity is localized in the perinuclear sarcoplasm. Macrophages show more intense acid phosphatase activity than do the muscle fibres. The formation of autophagic vacuoles is described and discussed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00222809
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