| dc.creator | RÍOS,EDUARDO | |
| dc.creator | ZHOU,JINGSONG | |
| dc.date | 2004-01-01 | |
| dc.date.accessioned | 2020-02-17T15:35:43Z | |
| dc.date.available | 2020-02-17T15:35:43Z | |
| dc.identifier | https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0716-97602004000400012 | |
| dc.identifier.uri | https://revistaschilenas.uchile.cl/handle/2250/132043 | |
| dc.description | Here we compare excitation-contraction coupling in single muscle cells of frogs and rats. Because amphibians have isoform 3 (or b) of the ryanodine receptor/Ca2+ release channel, in addition to 1 (a), which is also present in the mammal, any extra feature present in the frog may in principle be attributed to isoform 3. Ca2+ release under voltage clamp depolarization has a peak and a steady phase in both taxonomic classes, but the peak is more marked in the frog, where the ratio of amplitudes of the two phases is voltage-dependent. This dependence is a hallmark of CICR. Confocal imaging identified Ca2+ sparks in the frog, but not in the voltage-clamped rat cells. Because Ca2+ sparks involve CICR both observations indicate that the contribution of CICR is minor or null in the mammal. The "couplon" model well accounts for observations in the frog, but assumes a structure that we now know to be valid only for the rat. A revised model is proposed, whereby the isoform 3 channels, located parajunctionally, are activated by CICR and contribute its characteristic global and local features. Several issues regarding the roles of different channels remain open to further study. | |
| dc.format | text/html | |
| dc.language | en | |
| dc.publisher | Sociedad de Biología de Chile | |
| dc.relation | 10.4067/S0716-97602004000400012 | |
| dc.rights | info:eu-repo/semantics/openAccess | |
| dc.source | Biological Research v.37 n.4 2004 | |
| dc.subject | Excitation-contraction coupling | |
| dc.subject | sarcoplasmic reticulum | |
| dc.subject | Ca2+ sparks | |
| dc.subject | ryanodine receptor | |
| dc.subject | calcium-induced calcium release | |
| dc.title | Control of dual isoforms of Ca2+ release channels in muscle | |
