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L-Type Ca(2+) channel charge movement and intracellular Ca(2+) in skeletal muscle fibers from aging mice.
| Content Provider | Semantic Scholar |
|---|---|
| Author | Wang, Zhi Ming Messi, María Laura Delbono, Osvaldo |
| Copyright Year | 2000 |
| Abstract | In this work we tested the hypothesis that skeletal muscle fibers from aging mice exhibit a significant decline in myoplasmic Ca(2+) concentration resulting from a reduction in L-type Ca(2+) channel (dihydropyridine receptor, DHPR) charge movement. Skeletal muscle fibers from the flexor digitorum brevis (FDB) muscle were obtained from 5-7-, 14-18-, or 21-24-month-old FVB mice and voltage-clamped in the whole-cell configuration of the patch-clamp technique according to described procedures (Wang, Z.-M., M. L. Messi, and O. Delbono. 1999. Biophys. J. 77:2709-2716). Total charge movement or the DHPR charge movement was measured simultaneously with intracellular Ca(2+) concentration. The maximum charge movement (Q(max)) recorded (mean +/- SEM, in nC microF(-1)) was 53 +/- 3.2 (n = 47), 51 +/- 3.2 (n = 35) (non-significant, ns), and 33 +/- 1.9 (n = 32) (p < 0.01), for the three age groups, respectively. Q(max) corresponding to the DHPR was 43 +/- 3.3, 38 +/- 4.1 (ns), and 25 +/- 3.4 (p < 0.01) for the three age groups, respectively. The peak intracellular [Ca(2+)] recorded at 40 mV (in microM) was 15.7 +/- 0. 12, 16.7 +/- 0.18 (ns), and 8.2 +/- 0.07 (p < 0.01) for the three age groups, respectively. No significant changes in the voltage distribution or steepness of the Q-V or [Ca(2+)]-V relationship were found. These data support the concept that the reduction in the peak intracellular [Ca(2+)] results from a larger number of ryanodine receptors uncoupled to DHPRs in skeletal muscle fibers from aging mammals. |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | https://core.ac.uk/download/pdf/82178694.pdf |
| PubMed reference number | 10733973v1 |
| Volume Number | 78 |
| Issue Number | 4 |
| Journal | Biophysical journal |
| Language | English |
| Access Restriction | Open |
| Subject Keyword | Calcium Dihydropyridines Greater Hippocampus (Brain) Muscle Fibers Myalgia Patch-Clamp Techniques Ryanodine Skeletal Myocytes Tissue fiber voltage |
| Content Type | Text |
| Resource Type | Article |
