Introduction: Our previous experiments showed that the transient sodium current (I Na) was abnormally increased in early ischaemia and atorvastatin could inhibit I Na. The aim of this study was to observe the time-dependent effects of simulated ischaemia on I Na and characterise the direct effects of atorvastatin on ischaemic I Na. Methods: Left ventricular myocytes were isolated from Wistar rats and randomly divided into two groups: a control group (normal to simulated ischaemia) and a statin group (normal to simulated ischaemia with 5 μmol/l atorvastatin). The I Na was recorded under normal conditions (as baseline) by wholecell patch clamp and recorded from three to 21 minutes in the next phase of simulated ischaemic conditions. Results: In the control group, normalised I Na (at-40 mV) was increased to the peak (1.15 ± 0.08 mA) at three minutes of ischaemia compared with baseline (0.95 ± 0.04 mA, p < 0.01), it subsequently returned to baseline levels at nine and 11 minutes of ischaemia (0.98 ± 0.12 and 0.92 ± 0.12 mA, respectively), and persistently decreased with prolonged ischaemic time. In the statin group, there were no differences between baseline and the early stages of ischaemia (0.97 ± 0.04 mA at baseline vs 0.92 ± 0.12 mA in ischaemia for three minutes, p > 0.05). Conclusion: Our results suggest that, in the early stages of ischaemia, changes in I Na in ventricular myocytes are timedependent, showing an initial increase followed by a decrease, while atorvastatin inhibited the transient increase in I Na and made the change more gradual.

numbers of CMs for therapeutic cell transplantation. This study investigated the effect of co-culturing with native CMs on ascorbic acid-induced cardiomyogenic differentiation in embryonic stem cells, to develop a novel protocol for generating functional CMs from ESCs. Methods Native CMs were isolated from the hearts of 1-day-old Sprague-Dawley rats. Mouse ESCs were cultured in hanging drops to form embryoid bodies (EBs) and treated with or without 0.1 mM of ascorbic acid (Sigma) for cardiomyogenic differentiation. They were divided into four groups: ascorbic acid & co-culture group, co-culture group, ascorbic acid group, and control group. In the coculture system, EBs were co-cultured with native CMs by the hanging cell culture inserts (PET 1 mm) (Millicell; Millipore, Bedford, MA, USA). The native CMs were purposely placed on culture plate inserts to prevent direct contact with subnatant EBs. Both the ESCs and native CMs grew in the same medium but they were easy to separate. The structural and functional properties of ESC-derived CMs (ESCM) were evaluated by microscopic observation, immunocytochemistry, RT-PCR, and transmission electron microscopy. Results The average percentages of EBs exhibited rhythmic contractions in co-culture and ascorbic acid group, co-culture group, ascorbic acid group, and control group were 86.669.52%, 65.60610.77%, 29.666.03%, and 17.7665.99%, respectively. The percentage of beating EBs in co-culture & ascorbic acid group was much higher and the homogeneity of EBs were significantly improved over that seen in other groups (p<0.01), simultaneously, the automaticity of beating also maintained for more time. The majority (>90%) of cells in EBs were ESCM that acquired almost the same structural and functional properties as typical CMs. Conclusions The present study demonstrates the cardiomyogenic differentiation of ESCs can be efficiently controlled by co-cultured with native CMs, and this may lead to a practicable cocktail approach to generate ESC-derived CMs for stem cell-based regenerative medicine. Objective Bare metal stent (BMS) implantation can resolve renal artery stenosis successfully, but in-stent restenosis does occur, especially in small diameter renal arteries (<5.0 mm). The aim of this study is to test whether a newly designed polymer-free sirolimus and probucol-eluting stent (SPES) can inhibit neointimal hyperplasia of renal artery in swine. Methods 26 stents (18 SPES and 18 BMS) were implanted in 36 renal arteries of 18 animals. During every procedure, a SPES and a BMS were randomised to the right or left renal artery. Seven animals were sacrificed after 90 days, and 11 after 180 days. Results Histomorphometric analysis was performed. After 90 days, minimal lumen area, neointimal area, score of inflammation and score of endothelialisation were not significantly different between BMS and SPES. After 180 days, minimal lumen area was not significantly different between BMS and SPES (6.5562 Objective To observe time dependent effects of simulated ischaemia on transient sodi...

Objective To observe time dependent effects of simulated ischemia-reperfusion on transient sodium currents (I Na ) in rat left ventricular myocytes, and effects of atorvastatin on I Na in the condition of ischemia and reperfusion. Methods Fifty-four Wistar rats were used for isolating left ventricular myocytes, which were randomly divided into four groups: ischemia group (normal→ischemia→ischemia), reperfusion group (normal→ischemia→reperfusion), statinischemia group (normal→ischemia with 5 μmol/l atorvastatin) and statin-reperfusion group (normal→ischemia→reperfusion with 5 μmol/l atorvastatin). Firstly, I Na were recorded in normal I Na solution (for control) by whole-cell patchclamp. Then, in simulated ischemia solution, I Na were recorded from 3 min to 21 min. Finally, I Na were recorded again in normal I Na solution (simulate reperfusion). Results (1) Ischemia effects: In ischemia group, compared with normal (0.95±0.04), normalised currents (at −40 mV) of simulated ischemia were increased to peak at 3 min (1.15±0.08, p<0.01), returned at 9 min and 11 min (0.98±0.12 and 0.92±0.12, p>0.05, respectively), and decreased at 21 min (0.56±0.13, p<0.01). At simulated ischemia for 21 min, there were no signifi cant differences among ischemia group, reperfusion group and statin-reperfusion group. (2) Effects of atorvastatin on ischemia myocytes: in statin-ischemia group, there were no differences between nomal and simulated ischemia for 3 min (0.97±0.04 vs 0.92±0.12, p>0.05). (3) Reperfusion effects: compared with ischemia for 21 min, normalised currents (at −40 mV) in reperfusion group were decreased at reperfusion for 3 min from 0.83±0.11 to 0.57±0.09 (p<0.05), and decreased to 0.50±0.09 at reperfusion for 9 min (compared with 3 min p<0.05), while in ischemia group normalised currents were not changed again. And compared with ischemia group, normalised currents (at −40 mV) in reperfusion group were decreased at reperfusion for 3 to 9 min (p<0.01). (4) Effects of atorvastatin on reperfusion myocytes: compared with ischemia for 21 min, normalised currents (at −40 mV) in statin-reperfusion group were decreased at reperfusion for 3 min from 0.92±0.04 to 0.72±0.05 (p<0.01). And at reperfusion for 3 to 9 min, normalised currents in statin-reperfusion group were decreased compared with ischemia group, but increased compared with reperfusion group (p<0.01, respectively). Conclusions (1) The effects of simulated ischemia on I Na are time dependent, while I Na is transient increased at 3 min, but decreased 21 min (2) Simulated reperfusion make I Na more decreased from ischemia condition. (3) Atorvastatin can depress increased I Na at the period of early ischemia, and depress decreased I Na at the time of reperfusion.

Background Some clinical trials have shown statins have anti-arrhythmic effects and can improve clinical results. But its mechanism is unclear. Objective observing the effects of atorvastatin on transient sodium currents in rat normal/simulated ischemia/reperfusion ventricular cell. Methods Taking whole-cell patch clamp method to record INa and measuring the expression level of SCN5A by western blot technique of simulated ventricular ischemia /reperfusion cell. Results The short-time effects of atorvastatin on the rat normal and simulated ischemia ventricular peak INa were inhibited about 25% (p<0.05), and after elution, inhibition disappeared. However 15 min after simulated ischemia atorvastatin inhibited the INa decreasing progress. In simulated reperfusion status, INa reduced and atorvastatin inhibited the reduction degree, while INa of the atorvastatin and wortmannin combination group had no difference with which of reperfusion group (p>0.05). The expression level of SCN5A had the almost same changes with INa. Conclusion (1) The short time (3 min) effect of Atorvastatin in INa of the normal and simulated ischemia rat ventricular myocytes is inhibition, similar to sodium channel blockers. (2) Atorvastatin can protect the decrease of INa in the status of simulated long-time (>15 min) ischemia/reperfusion. (3) Effects of Atorvastatin in the status of simulated ischemic/reperfusion can be partly overcome by Wortmannin, which means atorvastatin can affect INa and the expression level of SCN5A through the way of RISK signal pathway especially of PI3K.