| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
1 Laboratory of Exercise Physiology, Division of Health Promotion and Exercise, National Institute of Health and Nutrition, 1-23-1 Toyama, Shinjuku City, Tokyo 162-8636; 2 Department of Physiology and Biomechanics, National Institute of Fitness and Sports, Kanoya City, Kagoshima Prefecture, 891-2393; and 3 Department of Sports Sciences, School of Human Sciences, Waseda University, Tokorozawa City, Saitama Prefecture, 359-1192, Japan
The
purpose of the present investigation was to establish a method for
estimating intracellular Ca2+ concentrations
([Ca2+]i) in isolated rat epitrochlearis
muscles. Epitrochlearis muscles excised from 4-wk-old male
Sprague-Dawley rats were loaded with a fluorescent Ca2+
indicator, fura 2-AM, for 60-90 min at 35°C in oxygenated
Krebs-Henseleit buffer. After fura 2 loading and subsequent 20-min
incubation, the intensities of 500-nm fluorescence, induced by 340- and
380-nm excitation lights (Ftotal340 and
Ftotal380), were measured. The fluorescences specific
to fura-2 (Ffura 2340 and Ffura 2380) were
calculated by subtracting the non-fura 2-specific component from
Ftotal340 and Ftotal380, respectively. The
ratio of Ffura 2340 to Ffura 2380 was
calculated as R, and the change in the ratio from the baseline value
(
R) was used as an index of the change in
[Ca2+]i. In resting muscle, R was stable
for 60 min. Incubation for 20 min with caffeine (3-10 mM)
significantly increased R in a concentration-dependent manner.
Incubation with hypoxic Krebs-Henseleit buffer for 10-60 min
significantly elevated R, depending on the duration of the
incubation. Incubation with 50 µM
N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide for 20 min significantly elevated R (P < 0.05). No
significant increases in R were observed during incubation for 20 min with 2 mM
5-aminoimidazole-4-carboxamide-1-
-D-ribofuranoside or
with 2 mU/ml insulin. These results demonstrated that, by using the fura 2-AM fluorescence method, the changes in
[Ca2+]i can be monitored in the rat
epitrochlearis muscle and suggest that the method can be utilized to
observe quantitative information regarding
[Ca2+]i that may be involved in contraction-
and hypoxia-stimulated glucose transport activity in skeletal muscle.
fura 2; hypoxia; 5-aminoimidazole-4-carboxamide-1--D-ribofuranoside; insulin; caffeine; intracellular Ca2+ concentration
This article has been cited by other articles:
|
|
 |
|
  K. Funai and G. D. Cartee Inhibition of Contraction-Stimulated AMP-Activated Protein Kinase Inhibits Contraction-Stimulated Increases in PAS-TBC1D1 and Glucose Transport Without Altering PAS-AS160 in Rat Skeletal Muscle Diabetes, May 1, 2009; 58(5): 1096 - 1104. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. J. Rose, T. J. Alsted, T. E. Jensen, J. B. Kobbero, S. J. Maarbjerg, J. Jensen, and E. A. Richter A Ca2+-calmodulin-eEF2K-eEF2 signalling cascade, but not AMPK, contributes to the suppression of skeletal muscle protein synthesis during contractions J. Physiol., April 1, 2009; 587(7): 1547 - 1563. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. A. Raney and L. P. Turcotte Evidence for the involvement of CaMKII and AMPK in Ca2+-dependent signaling pathways regulating FA uptake and oxidation in contracting rodent muscle J Appl Physiol, May 1, 2008; 104(5): 1366 - 1373. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. Sonobe, T. Inagaki, D. C. Poole, and Y. Kano Intracellular calcium accumulation following eccentric contractions in rat skeletal muscle in vivo: role of stretch-activated channels Am J Physiol Regulatory Integrative Comp Physiol, April 1, 2008; 294(4): R1329 - R1337. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. F. Kramer, E. B. Taylor, C. A. Witczak, N. Fujii, M. F. Hirshman, and L. J. Goodyear Calmodulin-Binding Domain of AS160 Regulates Contraction- but Not Insulin-Stimulated Glucose Uptake in Skeletal Muscle Diabetes, December 1, 2007; 56(12): 2854 - 2862. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. C. Wright, P. C. Geiger, D.-H. Han, T. E. Jones, and J. O. Holloszy Calcium Induces Increases in Peroxisome Proliferator-activated Receptor {gamma} Coactivator-1{alpha} and Mitochondrial Biogenesis by a Pathway Leading to p38 Mitogen-activated Protein Kinase Activation J. Biol. Chem., June 29, 2007; 282(26): 18793 - 18799. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. E. Jensen, A. J. Rose, S. B. Jorgensen, N. Brandt, P. Schjerling, J. F. P. Wojtaszewski, and E. A. Richter Possible CaMKK-dependent regulation of AMPK phosphorylation and glucose uptake at the onset of mild tetanic skeletal muscle contraction Am J Physiol Endocrinol Metab, May 1, 2007; 292(5): E1308 - E1317. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. J. Rose and E. A. Richter Skeletal Muscle Glucose Uptake During Exercise: How is it Regulated? Physiology, August 1, 2005; 20(4): 260 - 270. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. Jessen and L. J. Goodyear Contraction signaling to glucose transport in skeletal muscle J Appl Physiol, July 1, 2005; 99(1): 330 - 337. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. C. Wright, P. C. Geiger, J. O. Holloszy, and D.-H. Han Contraction- and hypoxia-stimulated glucose transport is mediated by a Ca2+-dependent mechanism in slow-twitch rat soleus muscle Am J Physiol Endocrinol Metab, June 1, 2005; 288(6): E1062 - E1066. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. C. Wright, K. A. Hucker, J. O. Holloszy, and D. H. Han Ca2+ and AMPK Both Mediate Stimulation of Glucose Transport by Muscle Contractions Diabetes, February 1, 2004; 53(2): 330 - 335. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Terada and I. Tabata Effects of acute bouts of running and swimming exercise on PGC-1{alpha} protein expression in rat epitrochlearis and soleus muscle Am J Physiol Endocrinol Metab, February 1, 2004; 286(2): E208 - E216. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
