Journal article
Sodium current kinetics of transitional myocytes in Koch triangle of rabbit hearts
Chinese Medical Journal, Vol.121(21), pp.2185-2191
2008
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Abstract
<p>Background Few studies have explored the inward sodium current (INa) kinetics of transitional cardiomyocytes. This study aimed to explore the kinetics of transitional cardiomyocytes types α and β. <br /> Methods The whole-cell patch clamp technique was used to study the rapid INa of isolated transitional cardiomyocytes in the Koch triangle of rabbit hearts. <br /> Results Maximal amplitude and density of INa in type α and type β was (–1627±288) pA (α), ( –35.17±6.56) pA/pF (β) and (–3845±467) pA (α), (–65.64±10.23) pA/pF (β) (<em>P</em> <0.05). Steady state activation curves of INa, fitted to a Boltzmann distribution for both types, were sigmoid in shape. Half activation voltage and slope factors did not significantly differ between types at (–43.46±0.85) mV (α), (–41.39±0.47) mV (β) or (9.04±0.66) mV (α), (11.08±0.89) mV (β). Steady state inactivation curves of INa, fitted to a Boltzmann distribution in both types were inverse “S” shape. Half inactivation voltage and slope factors were (–109.9±0.62) mV (α), (–107.5±0.49) mV (β) and (11.78±0.36) mV (α), (11.57±0.27) mV (β), (<em>P</em> >0.05), but time constants of inactivation were significantly different at (1.10±0.19) mV (α) and (2.37±0.33) ms (β), (<em>P</em> <0.05). Time constants of recovery from inactivation of INa for both types were (122.16±27.43) mV (α) and (103.84±28.97) ms (β) (<em>P</em> <0.05). <br /> Conclusions Transitional cardiomyocytes in rabbit hearts show a heterogeneous, voltage gated and time dependent fast inward sodium current. Types α and β show the features of INa similar to those in slow- and fast-response myocytes, with probably better automaticity and conductivity, respectively.</p>
Details
- Title
- Sodium current kinetics of transitional myocytes in Koch triangle of rabbit hearts
- Creators
- Fu-xian Ren - Xi’an Jiaotong UniversityXiao-Lin Niu - Ministry of Education, Xi’anYan Ou - Xi’an Jiaotong UniversitySong-Mei Xie - Xi’an Jiaotong UniversityFeng-Dong Ling - Xi’an Jiaotong UniversityShi Zhou - Dalian UniversityYa-Jie Li - Dalian University
- Publication Details
- Chinese Medical Journal, Vol.121(21), pp.2185-2191
- Identifiers
- 2693; 991012821109502368
- Academic Unit
- Faculty of Health; School of Health and Human Sciences; Human Sciences
- Resource Type
- Journal article