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Comparison of the effects of inorganic phosphate on caffeine-induced Ca2+ release in fast- and slow-twitch mammalian skeletal muscle

, : Comparison of the effects of inorganic phosphate on caffeine-induced Ca2+ release in fast- and slow-twitch mammalian skeletal muscle. American Journal of Physiology. Cell Physiology 294(1): C97-105

We compared the effects of 50 mM P(i) on caffeine-induced Ca(2+) release in mechanically skinned fast-twitch (FT) and slow-twitch (ST) skeletal muscle fibers of the rat. The time integral (area) of the caffeine response was reduced by approximately 57% (FT) and approximately 27% (ST) after 30 s of exposure to 50 mM P(i) in either the presence or absence of creatine phosphate (to buffer ADP). Differences in the sarcoplasmic reticulum (SR) Ca(2+) content between FT and ST fibers [ approximately 40% vs. 100% SR Ca(2+) content (pCa 6.7), respectively] did not contribute to the different effects of P(i) observed; underloading the SR of ST fibers so that the SR Ca(2+) content approximated that of FT fibers resulted in an even smaller ( approximately 21%), but not significant, reduction in caffeine-induced Ca(2+) release by P(i). These observed differences between FT and ST fibers could arise from fiber-type differences in the ability of the SR to accumulate Ca(2+)-P(i) precipitate. To test this, fibers were Ca(2+) loaded in the presence of 50 mM P(i). In FT fibers, the maximum SR Ca(2+) content (pCa 6.7) was subsequently increased by up to 13 times of that achieved when loading for 2 min in the absence of P(i). In ST fibers, the SR Ca(2+) content was only doubled. These data show that Ca(2+) release in ST fibers was less affected by P(i) than FT fibers, and this may be due to a reduced capacity of ST SR to accumulate Ca(2+)-P(i) precipitate. This may account, in part, for the fatigue-resistant nature of ST fibers.


PMID: 17959728

DOI: 10.1152/ajpcell.00155.2007

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Shamov, I.A., 1984: Viral hepatitis complicated by hemolytic anemia. The author describes a case of virus hepatitis which was complicated at the 43d day of staying at hospital by the development of grave hemolytic anemia accompanied by hemoglobin fall down to 3.6 g% and red cell count decrease to l 250 000 per mm3....

Cooke, R.; Morales, M.F., 1969: Spin-label studies of glycerinated muscle fibers. Biochemistry 8(8): 3188-3194

Anderson, P.L.; Morrison, R.B.; Thawley, D.G.; Molitor, T., 1989: Identification of pseudorabies virus-infected swine herds by evaluating the serostatus of boars or finishing pigs. Data were collected from 39 Minnesota swine farms quarantined for pseudorabies virus (PRV) infection. Each herd was serologically evaluated for antibodies to PRV in the sows, boars, and finishing pigs. To identify PRV-seropositive swine herds, the...

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Reis, K.J.; Siden, E.J.; Boyle, M.D., 1988: Selective colony blotting to expand bacterial surface receptors: applications to receptors for rat immunoglobulins. Many bacterial surface receptors demonstrate a heterogeneous expression pattern among individual colonies. Methods have been developed to select bacteria expressing high levels of a stable surface receptor. This process is illustrated using a Stre...