Diffusional and Electrical Properties of T-Tubules Are Governed by Their Constrictions and Dilations.

ABSTRACT: Cardiac t-tubules (TTs) form a network of complex surface membrane invaginations that is essential for proper excitation-contraction coupling. Although electron and optical microscopy studies provided a wealth of important information about the structure of TTs, assessing their functional properties remains a challenge. In this study, we investigated the diffusional accessibility of TTs in intact isolated adult mouse ventricular myocytes using, to our knowledge, a novel fluorescence-based assay. In this approach, a small part of TTs is first locally filled with fluorescent dextran and then its diffusion out of TTs is monitored after rapid removal of extracellular dextran. In normal cells, diffusion of 3 kDa dextran is characterized by an average time constant of 3.9 ± 1.2 s with the data r

SUBMITTER: Uchida K 

PROVIDER: S-EPMC5984979 | biostudies-literature | 2018 Jan

REPOSITORIES: biostudies-literature