+ Site Statistics
+ Search Articles
+ PDF Full Text Service
How our service works
Request PDF Full Text
+ Follow Us
Follow on Facebook
Follow on Twitter
Follow on LinkedIn
+ Subscribe to Site Feeds
Most Shared
PDF Full Text
+ Translate
+ Recently Requested

Imaging caffeine-induced Ca2+ transients in individual fast-twitch and slow-twitch rat skeletal muscle fibers



Imaging caffeine-induced Ca2+ transients in individual fast-twitch and slow-twitch rat skeletal muscle fibers



American Journal of Physiology 274(3): C623



Fast-twitch and slow-twitch rat skeletal muscles produce dissimilar contractures with caffeine. We used digital imaging microscopy to monitor Ca2+ (with fluo 3-acetoxymethyl ester) and sarcomere motion in intact, unrestrained rat muscle fibers to study this difference. Changes in Ca2+ in individual fibers were markedly different from average responses of a population. All fibers showed discrete, nonpropagated, local Ca2+ transients occurring randomly in spots about one sarcomere apart. Caffeine increased local Ca2+ transients and sarcomere motion initially at 4 mM in soleus and 8 mM in extensor digitorum longus (EDL; approximately 23 degrees C). Ca2+ release subsequently adapted or inactivated; this was surmounted by higher doses. Motion also adapted but was not surmounted. Prolonged exposure to caffeine evidently suppressed myofilament interaction in both types of fiber. In EDL fibers, 16 mM caffeine moderately increased local Ca2+ transients. In soleus fibers, 16 mM caffeine greatly increased Ca2+ release and produced propagated waves of Ca2+ (approximately 1.5-2.5 microns/s). Ca2+ waves in slow-twitch fibers reflect the caffeine-sensitive mechanism of Ca2(+)-induced Ca2+ release. Fast-twitch fibers possibly lack this mechanism, which could account for their lower sensitivity to caffeine.

Please choose payment method:






(PDF emailed within 1 workday: $29.90)

Accession: 008814275

Download citation: RISBibTeXText

PMID: 9530093


Related references

Imaging caffeine-induced Ca2+transients in individual fast-twitch and slow-twitch rat skeletal muscle fibers. American Journal of Physiology. Cell Physiology 274(3): C623-C632, 2018

Lactate dehydrogenase isoenzymes: distribution in fast-twitch red, fast-twitch white, and slow-twitch intermediate fibers of guinea pig skeletal muscle. Archives of Biochemistry and Biophysics 144(1): 304-307, 1971

Calcium transients in rat intact fast- and slow-twitch skeletal muscle fibers. Biophysical Journal 68(2 Part 2): A177, 1995

Functional differences between mammalian fast twitch and slow twitch skeletal muscle fibers. Res Muscular Dystrophy Proc Symp 3: 271-280, 1965

Isometric leg exercise and glycogen depletion in fast twitch and slow twitch fibers in human skeletal muscle. Acta Physiologica Scandinavica Supplementum 396: 72, 1973

Differential expression of ankyrinsG during postnatal development of fast-twitch and slow-twitch skeletal muscle fibers. Biology of the Cell 93(3-4): 233, 2001

Distribution of alpha 1 adrenergic receptors in muscle fibers and vessels of slow twitch fast twitch and mixed skeletal muscles. Circulation 80(4 Suppl. 2): II557, 1989

The role of parvalbumin in the decay of calcium after electrical stimulation in intact rat fast-twitch and slow-twitch skeletal muscle fibers. FASEB Journal 10(6): A1395, 1996

Collagen of slow twitch and fast twitch muscle fibers in different types of rat skeletal muscle. European Journal of Applied Physiology and Occupational Physiology 52(2): 235-242, 1984

Dynamic regulation of calcium handling by phosphorylation and dephosphorylation in mouse single fast-twitch and slow-twitch skeletal muscle fibers. Biophysical Journal 72(2 Part 2): A275, 1997

Myosin phosphorylation and twitch potentiation in rat fast twitch and slow twitch skeletal muscle. Biophysical Journal 33(2 Part 2): 226A, 1981

Energy metabolism of fast twitch and slow twitch skeletal muscle in the rat thyroid hormone induced changes. Journal of Comparative Physiology B Biochemical Systemic and Environmental Physiology 142(4): 465-472, 1981

Skeletal muscle fibers from fast twitch muscles in the rat are more susceptible to mechanical inactivation than fibers from slow twitch muscles. Biophysical Journal 49(2 Part 2): 189A, 1986

Fast twitch human muscle fibers have a greater increase in sodium channel density near the endplate than slow twitch fibers. Neurology 42(4 Suppl. 3): 231, 1992

Capillary supply and cross sectional area of slow twitch muscle fibers and fast twitch muscle fibers in man. Histochemistry 76(4): 547-556, 1982