ISSN:
1432-0878
Keywords:
Cardiac sarcomere
;
Lycosidae, Pisauridae (Araneae)
;
T-tubules
;
Sarcoplasmic reticulum
;
Couplings
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Summary The ultrastructure of the cardiac muscle in some araneae has been investigated. The sarcolemma invaginates at the Z band and may extend into the cells through several myofibrils. Numerous T-tubules are given off both from sarcolemmal invaginations and also directly from the cell surface. In passing through the Z band, the luminal diameter of T-tubules greatly increases. Dyadic and a few triadic couplings are found mainly at the A-I level. Peripheral couplings were not seen. The ruthenium red solutions employed were prepared as described by Myklebust (1975), but the fixative contained 2% sucrose. The hearts were fixed for 3 1/2h in the ice cold solution, washed in buffer and post-fixed for 1 1/2h in a ruthenium red/OsO4 solution. Dehydration and embedding was performed as described above. Sections were cut on a Reichert Om U2 microtome, stained with lead citrate (Reynolds, 1963) and examined in a Philips 300 electron microscope at 80 kV. Semithin sections for light microscopy were stained with toluidine blue (Mercer and Birbeck, 1972).
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00223105
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