The Skeletal L-type Ca2+ Current Is a Major Contributor to Excitation-coupled Ca2+ entry
نویسندگان
چکیده
منابع مشابه
The Skeletal L-type Ca2+ Current Is a Major Contributor to Excitation-coupled Ca2+ entry
The term excitation-coupled Ca(2+) entry (ECCE) designates the entry of extracellular Ca(2+) into skeletal muscle cells, which occurs in response to prolonged depolarization or pulse trains and depends on the presence of both the 1,4-dihydropyridine receptor (DHPR) in the plasma membrane and the type 1 ryanodine receptor in the sarcoplasmic reticulum (SR) membrane. The ECCE pathway is blocked b...
متن کاملThe Skeletal L - type Ca 2 + Current Is a Major Contributor to Excitation - coupled Ca 2 + entry Roger
The skeletal muscle L-type Ca 2+ channel (1,4-dihydropyridine receptor [DHPR]) serves as the voltage sensor for excitation – contraction (EC) coupling ( Tanabe et al., 1988 ). Conformational changes in the DHPR in response to membrane depolarization are coupled to gating of the type 1 RYR (RYR1) of the SR ( Beam and Horowicz, 2004 ). The resultant Ca 2+ effl ux via RYR1 into the myoplasm initia...
متن کاملCa2+ entry-independent effects of L-type Ca2+ channel modulators on Ca2+ sparks in ventricular myocytes.
During the cardiac action potential, Ca(2+) entry through dyhidropyridine receptor L-type Ca(2+) channels (DHPRs) activates ryanodine receptors (RyRs) Ca(2+)-release channels, resulting in massive Ca(2+) mobilization from the sarcoplasmic reticulum (SR). This global Ca(2+) release arises from spatiotemporal summation of many localized elementary Ca(2+)-release events, Ca(2+) sparks. We tested w...
متن کاملDifferential regulation of skeletal muscle L-type Ca2+ current and excitation-contraction coupling by the dihydropyridine receptor beta subunit.
The dihydropyridine receptor (DHPR) of skeletal muscle functions as a Ca2+ channel and is required for excitation-contraction (EC) coupling. Here we show that the DHPR beta subunit is involved in the regulation of these two functions. Experiments were performed in skeletal mouse myotubes selectively lacking a functional DHPR beta subunit. These beta-null cells have a low-density L-type current,...
متن کاملL-type Ca2+ current and excitation-contraction coupling in single atrial myocytes from rainbow trout.
We have examined the contribution of L-type Ca2+ current ( I Ca) to the activation of contraction in trout atrial myocytes under basal and phosphorylating conditions. The average myocyte length was 197 ± 14 μm, width was 5.5 ± 0.2 μm, and cell capacitance was 36.2 ± 2.2 pF. With 25 μM EGTA in the patch pipette and a stimulation frequency of 0.125 Hz, I Cawas 2.6 ± 0.4 pA/pF and it carried a tot...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Journal of General Physiology
سال: 2008
ISSN: 1540-7748,0022-1295
DOI: 10.1085/jgp.200810105