Changes of Na(+) channels in rat hippocampal CA1 neurons in early development after birth / 生理学报

The purpose of this research is to investigate the critical period of voltage-gated Na(+) channel development in hippocampal CA1 neurons. Changes of Na(+) currents in acutely isolated hippocampal CA1 neurons of rats at different ages (0-4 weeks after birth) were recorded using the whole-cell patch-clamp technique. The results indicated that the maximum current density of Na(+) channels was increasing with age, and the amplitudes in 1, 2, 3 and 4 weeks respectively grew by (42.76 ± 4.91)%, (146.80 ± 7.63)%, (208.79 ± 5.28)% and (253.72 ± 5.74)% (n = 10, P < 0.05) compared with that in 0 week. The current density in CA1 neurons of 1-2 weeks after birth increased more significantly than those of other groups. The activation curve of Na(+) channel shifted to the left. The half-activation voltages (mV) in 0-2 weeks were -39.06 ± 0.65, -43.41 ± 0.52, -48.29 ± 0.45 (n = 10, P < 0.05), respectively, showing significant age-dependent decrease, and there were no significant changes in other groups. The slope factors of activation curve for each group did not change significantly. There were no regular changes in inactivation curve and no significant changes in half-inactivation voltage. The slope factors of inactivation curve in 1-2 weeks were: 5.77 ± 0.56, 4.42 ± 0.43 (n = 10, P < 0.05). The inactivation rate of the second week after birth was faster than that of the first week, and there were no significant changes during 0-1 week and 2-4 weeks. The recovery from inactivation curve of Na(+) channel shifted to the left. The recovery time declined in 1-3 weeks. Changes of action potential properties were consistent with Na(+) current. These results suggest that the period of 1-2 weeks after birth may be the critical development period of voltage-gated Na(+) channel in hippocampal CA1 neurons. During this time, the distribution of Na(+) channel increases significantly; the activation curve of Na(+) channel shifts to the left; inactivation rate increases as well as recovery time shortens.

Serum B-type natriuretic peptide changes in patients with acute coronary syndrome during percutaneous coronary intervention / 中华急诊医学杂志

Objective To observe the serum B-type natriuretic peptide(BNP)changes in patients with acute coronary syndrome during percutaneous coronary intervention(PCI).Method The serum BNP level was determined and the heart function was assessed in 236 consecutive patients with acute coronary syndrome(ACS) admitted to CCU and in 54 normal normal suvjects as control from January 2005 to December 2006 in Tongji Hospital.The ACS patients were further divided into various subgroups according to the involved arteries and performance of PCI.Serum BNP,hypersensitive c respose protein(HsCRP)level,amd heart comstitution and function were analyzed.Results The serum BNP and HsCRP level were significantly increased in patients with ACS [(332.06?483.17)ng/L and(31.06?52.15)mg/L]more than those in normal subjects [(81.44?195.55)ng/L and(11.15?20.78)mg/L,respectively,P