CONTRIBUTION OF THE TRANSVERSE TUBULAR SYSTEM TO THE MEMBRANE CAPACITANCE OF STRIATED MUSCLE OF THE TOAD (BUFO MARINUS )

1966 ◽  
Vol 44 (1) ◽  
pp. 9-22 ◽  
Author(s):  
ID Pugsley
Keyword(s):  
Striated Muscle ◽  
Bufo Marinus ◽  
Membrane Capacitance ◽  
Transverse Tubular System ◽  
Tubular System ◽  
Toad Bufo

The Ultrastructure of the White Striated Myotomal Muscle of the Cod, Gadus morhua

1967 ◽  
Vol 24 (12) ◽  
pp. 2549-2553 ◽  
Author(s):  
C. M. Bishop ◽  
P. H. Odense
Keyword(s):  
Skeletal Muscle ◽  
Sarcoplasmic Reticulum ◽  
Cross Section ◽  
Actin Filaments ◽  
Gadus Morhua ◽  
Striated Muscle ◽  
Fish Muscle ◽  
Transverse Tubular System ◽  
Tubular System ◽  
Myotomal Muscle

The structure of the white skeletal muscle of the cod (Gadus morhua) is described. The peripheral fibrils are ribbon-like and rectangular in cross section with the long axis normal to the sarcolemma. The inner fibrils are mainly polygonal in cross section. Most of the mitochondria and nuclei are peripheral to the fibrils and next to the sarcolemma. The arrangement of the contractile proteins is typical for striated muscle, and the sarcoplasmic reticulum and transverse tubular system are similar to those in other white skeletal fish muscle. A distinct N-band is apparent with indications of branching and reorientation of the actin filaments. Mitochondria are often closely associated with the Z line.

scholarly journals Some Relations between Changes in the Linear Electrical Properties of Striated Muscle Fibers and Changes in Ultrastructure

1967 ◽  
Vol 50 (10) ◽  
pp. 2437-2458 ◽  
Author(s):  
W. H. Freygang ◽  
S. I. Rapoport ◽  
L. D. Peachey
Keyword(s):  
Electrical Properties ◽  
Time Constant ◽  
Striated Muscle ◽  
Sartorius Muscle ◽  
Transverse Tubular System ◽  
Tubular System ◽  
In Series ◽  
Striated Muscle Fibers ◽  
Frog Sartorius ◽  
Good Agreement

Some of the linear electrical properties of frog sartorius muscle have been investigated in Ringer's fluid and in a Ringer fluid made hypertonic by the addition of sucrose or NaCl. Electrical constants were determined from measurements of the phase angle of the admittance of a fiber for an applied alternating current, from measurements of the voltage induced by an inward pulse of current, and from measurements of the conduction velocity of the action potential and the time constant of its foot. The dilation of the transverse tubular system induced by the sucrose hypertonic Ringer fluid was correlated with the change in the electrical constants. From this it is concluded that a two time constant equivalent circuit for the membrane, as proposed by Falk and Fatt, is in good agreement with our results. Both the area of the membrane of the transverse tubular system, and the capacity (ce) attributed to it, increased in the sucrose hypertonic Ringer fluid. The resistance re, which is in series with ce, did not fall when the transverse tubular system was dilated and probably is not located in that system.

scholarly journals Nickel Substitution for Calcium in Excitation-Contraction Coupling of Skeletal Muscle

1967 ◽  
Vol 50 (6) ◽  
pp. 1709-1728 ◽  
Author(s):  
Donald A. Fischman ◽  
Roy C. Swan
Keyword(s):  
Action Potentials ◽  
Striated Muscle ◽  
Divalent Cations ◽  
Ringer Solution ◽  
Sartorius Muscle ◽  
Transverse Tubular System ◽  
Solution Studies ◽  
Ca Substitution ◽  
Tubular System ◽  
Spread Of Excitation

In 1962 Frank (22) reported that the addition of any one of a number of divalent cations, including Ni, to a Ca-free Ringer solution prevented the rapid loss of contractility seen in the absence of external Ca. To investigate further the Ni-Ca substitution, studies were made of 45Ca and 63Ni exchange during contraction and at rest using frog striated muscle. In contrast to 45Ca, it was found that there is no increase of 63Ni uptake associated with a K contracture of the sartorius muscle. The rates of loss of 63Ni and 45Ca from resting toe muscles previously bathed in the respective radioisotopes are not significantly different. Resting and action potentials, after 1 hr in a Ringer solution with Ni replacing Ca, closely resemble these potentials in normal Ca-Ringer's solution. Studies on the syneresis of isolated myofibrils indicate that Ni cannot replace Ca in activating this reaction. It is suggested that Ca is required for at least two steps in E-C coupling: one is the spread of excitation at the sarcolemma and transverse tubular system; the second is the activation of actomyosin ATPase. Conceivably Ni can substitute for Ca in the former but not in the latter.

scholarly journals Retinoid processing in retinal pigment epithelium of toad (Bufo marinus).

1994 ◽  
Vol 269 (35) ◽  
pp. 21983-21989 ◽  
Author(s):  
T.I. Okajima ◽  
B. Wiggert ◽  
G.J. Chader ◽  
D.R. Pepperberg
Keyword(s):  
Retinal Pigment Epithelium ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Bufo Marinus ◽  
Toad Bufo
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