| First Author | Ikemoto T | Year | 1997 |
| Journal | J Physiol | Volume | 501 ( Pt 2) |
| Pages | 305-12 | PubMed ID | 9192302 |
| Mgi Jnum | J:41892 | Mgi Id | MGI:894599 |
| Doi | 10.1111/j.1469-7793.1997.305bn.x | Citation | Ikemoto T, et al. (1997) Functional and morphological features of skeletal muscle from mutant mice lacking both type 1 and type 3 ryanodine receptors. J Physiol 501(Pt 2):305-12 |
| abstractText | 1. We generated mice with targeted disruptions in the genes for both ryanodine receptor type 1 (RyR-1) and type 3 (RyR-3) to study the functional roles of RyR subtypes in skeletal muscle. 2. In permeabilized myocytes lacking both the RyRs, the Ca(2+)-induced Ca2+ release (CICR) mechanism was completely lost, and caffeine failed to induce Ca2+ release. 3. Replacement of potassium methanesulphonate in an experimental intracellular solution with choline chloride resulted in Ca2+ release in the wild-type muscle but not in the mutant muscle lacking RyR-1. 4. The double-mutant mice exhibited more severe muscular degeneration than RyR-1-deficient mice with formation of large vacuoles and swollen mitochondria while structural coupling between T-tubules and the sarcoplasmic reticulum was retained. 5. These results demonstrate that CICR is mediated solely by RyR-1 and RyR-3 in skeletal muscle cells, and suggest that RyR-1 is involved in Cl(-)-induced Ca2+ release. The results also suggest the presence of molecular components other than RyRs responsible for the triad formation. RyR-3 may have a role in the normal morphogenesis of skeletal muscle cells, although functionally it can be replaced by RyR-1. |
