scholarly journals Weekly Versus Monthly Testosterone Administration on Fast and Slow Skeletal Muscle Fibers in Older Adult Males

2015 ◽  
Vol 100 (2) ◽  
pp. E223-E231 ◽  
Author(s):  
Robert H. Fitts ◽  
James R. Peters ◽  
E. Lichar Dillon ◽  
William J. Durham ◽  
Melinda Sheffield-Moore ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Older Adult ◽  
Muscle Fibers ◽  
Adult Males ◽  
Slow Skeletal Muscle ◽  
Skeletal Muscle Fibers ◽  
Testosterone Administration

Effect of External Calcium and other Divalent Cations on K+ Contractures in Denervated Slow Skeletal Muscle Fibers of the Frog

2019 ◽  
Author(s):  
Leonardo Hernández
Keyword(s):  
Skeletal Muscle ◽  
Binding Capacity ◽  
Divalent Cations ◽  
Muscle Fibers ◽  
Free Calcium ◽  
Slow Skeletal Muscle ◽  
Skeletal Muscle Fibers ◽  
Free Calcium Concentration ◽  
Chronic Denervation ◽  
Denervated Muscles

The influence of Ca2+ and other divalent cations on contractile responses of slow skeletal muscle fibers of the frog (Rana pipiens) under conditions of chronic denervation was investigated.Isometric tension was recorded from slow bundles of normal and denervated cruralis muscle in normal solution and in solutions with free calcium concentration solution or in solutions where other divalent cations (Sr2+, Ni2+, Co2+ or Mn2+) substituted for calcium. In the second week after nerve section, in Ca2+-free solutions, we observed that contractures (evoked from 40 to 80 mM-K+) of non-denervated muscles showed significantly higher tensions (p<0.05), than those from denervated bundles. Likewise, in solutions where calcium was substituted by all divalent cations tested, with exception of Mn2+, the denervated bundles displayed lower tension than non-denervated, also in the second week of denervation. In this case, the Ca2+ substitution by Sr2+ caused the higher decrease in tension, followed by Co2+ and Ni2+, which were different to non-denervated bundles, as the lowest tension was developed by Mn2+, followed by Co2+, and then Ni2+ and Sr2+. After the third week, we observed a recovery in tension. These results suggest that denervation altering the binding capacity to divalent cations of the voltage sensor.

scholarly journals Nerve Activity-dependent Modulation of Calcineurin Signaling in Adult Fast and Slow Skeletal Muscle Fibers

2001 ◽  
Vol 276 (48) ◽  
pp. 45243-45254 ◽  
Author(s):  
Shannon E. Dunn ◽  
Alain R. Simard ◽  
Rhonda Bassel-Duby ◽  
R. Sanders Williams ◽  
Robin N. Michel
Keyword(s):  
Skeletal Muscle ◽  
Muscle Fibers ◽  
Nerve Activity ◽  
Slow Skeletal Muscle ◽  
Skeletal Muscle Fibers ◽  
Activity Dependent ◽  
Calcineurin Signaling

Effects of Cannabinoids on Tension Induced by Acetylcholine and Choline in Slow Skeletal Muscle Fibers of the Frog

2013 ◽  
Vol 247 (1) ◽  
pp. 57-62 ◽  
Author(s):  
Xóchitl Trujillo ◽  
Enrique Sánchez-Pastor ◽  
Felipa Andrade ◽  
Miguel Huerta
Keyword(s):  
Skeletal Muscle ◽  
Muscle Fibers ◽  
Slow Skeletal Muscle ◽  
Skeletal Muscle Fibers

beta-Adrenergic modulation of Ba2+ currents and K+ contractures in frog slow skeletal muscle fibers

1997 ◽  
Vol 272 (1) ◽  
pp. C77-C81 ◽  
Author(s):  
M. Huerta ◽  
X. Trujillo ◽  
C. Vasquez
Keyword(s):  
Skeletal Muscle ◽  
Muscle Fibers ◽  
Isometric Tension ◽  
External Application ◽  
Beta Adrenergic ◽  
Cyclic Monophosphate ◽  
Slow Skeletal Muscle ◽  
Skeletal Muscle Fibers ◽  
Adrenergic Modulation ◽  
Ca2 Channels

beta-Adrenergic modulation of the Ba2+ current (IBa) and K+ contracture in slow skeletal muscle fibers of the frog (Rana pipiens) were investigated in intact fibers with the three-microelectrode voltage-clamp technique and isometric tension measurements. Application of epinephrine (10(-6) to 10(-5) M) to the bath increased the amplitude of IBa. This increase was blocked by the beta-antagonist propranolol (3 microM), and a similar increase was observed with the beta-specific agonist isoproterenol (1 microM). Thus the epinephrine effect was mediated mainly by beta-adrenergic receptors. External application of permeable 8-bromoadenosine 3',5'-cyclic monophosphate (0.5 mM) increased the amplitude of both IBa and K+ contractures. The present results suggest that beta-adrenergic modulation of IBa in slow skeletal muscle fibers could reflect a modulation of Ca2+ channels via adenosine 3',5'-cyclic monophosphate (cAMP). cAMP (0.5 mM) also potentiated the K(+)-evoked tension in these slow fibers. The physiological contribution made by the modulation of slow skeletal muscle Ca2+ channels to the increase in tension is still not completely understood.

scholarly journals Glibenclamide increases post-fatigue tension in slow skeletal muscle fibers of the chicken

2010 ◽  
Vol 181 (3) ◽  
pp. 403-412 ◽  
Author(s):  
Felipa Andrade ◽  
Xóchitl Trujillo ◽  
Enrique Sánchez-Pastor ◽  
Rocío Montoya-Pérez ◽  
Alfredo Saavedra-Molina ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Muscle Fibers ◽  
Slow Skeletal Muscle ◽  
Skeletal Muscle Fibers

Effects of denervation on Ca2+ channels in slow skeletal muscle fibers of the frog

2001 ◽  
Vol 126 (1) ◽  
pp. 91-99 ◽  
Author(s):  
Clemente Vásquez ◽  
Miguel Huerta ◽  
Xóchitl Trujillo ◽  
José Luis Marı́n ◽  
Leonardo Hernández
Keyword(s):  
Skeletal Muscle ◽  
Muscle Fibers ◽  
Slow Skeletal Muscle ◽  
Skeletal Muscle Fibers ◽  
Ca2 Channels
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