ISSN:
1432-0878
Keywords:
Skeletal muscle (Mouse)
;
Acid phosphatase
;
Lysosomes
;
Vacuolation
;
Endocytosis
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Summary Incubation of mouse skeletal muscle in a physiological Ringer solution containing protamine (60 μg/ml) at +37° C for 1 h induced ultrastructural changes including proliferation of tubular profiles and vesicles at the I-band level close to the A-I junction, formation of numerous acid phosphatase positive lysosomes in the longitudinal sarcoplasmic reticulum and autophagic vacuolation starting at the level of the A-I junction. Biochemical determination of acid phosphatase in the incubated muscles showed that protamine caused an increase in acid phosphatase activity of about 25 % compared to enzyme activities obtained from muscles incubated without protamine at +37°C or with protamine at +4°C. The morphological findings suggest that the vesicles arising adjacent to the A-I junction originate from transverse tubules. Such vesicles, designated as endocytic, may acquire acid phosphatase activity in the longitudinal SR and be active in an autophagic process resulting in large vacuoles. A causal relationship between endocytosis and lysosomal activation is suggested.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00219650
Permalink