Publication details
Quantification of t-tubule area and protein distribution in rat cardiac ventricular myocytes
| Authors | |
|---|---|
| Year of publication | 2008 |
| Type | Article in Periodical |
| Magazine / Source | Progress in Biophysics and Molecular Biology |
| MU Faculty or unit | |
| Citation | |
| Field | Biophysics |
| Keywords | cardiac cell; transverse-axial tubular system; tubular membrane area; tubular membrane capacitance |
| Description | The transverse (t-) tubules of cardiac ventricular myocytes are invaginations of the surface membrane that form a complex network within the cell. Many of the key proteins involved in excitation-contraction coupling appear to be located predominantly at the t-tubule membrane. Despite their importance, the fraction of cell membrane within the ttubules remains unclear: measurement of cell capacitance following detubulation suggests 32%, whereas optical measurements suggest up to 65%. We have, therefore, investigated the factors that may account for this discrepancy. Calculation of the combinations of t-tubule radius, length and density that produce t-tubular membrane fractions of 32% or 56% suggest that the true fraction is at the upper end of this range. Assessment of detubulation using confocal and electron microscopy suggests that incomplete detubulation can account for some, but not all of the difference. |
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