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To investigate the effects of taurine and Astragalus membranaceus (AM) on ion currents and their expression in cardiomyocytes after Coxsackie virus B3 (CVB3) infection, hearts were removed from adult or newborn Sprague-Dawley rats and digested by collagenase. CVB3 was inoculated to the medium and used for recording current of L-type voltage-dependent calcium channel (Ica), Na⁺ current (INa), outward potassium current (Iout), and inward rectifying potassium current (IKI). An in vivo model of viral myocarditis (VMC) was produced by intraperitoneal injection of CVB3 into BALB/c mice and the hearts were used for examining the expression of L-type voltage-dependent Ca²⁺ channel (LVDCC)α1 subunit and the voltage-gated potassium channel (Kv). Ica and Iout were increased while IKI decreased after inoculation with CVB3 for 2 h. However, INa did not differ between normal and infected cells. The positive hybridization signals of the LVDCCα1 subunit (antigen) and Kv1.2, Kv2.1, and Kv4.2 were much reinforced after CVB3 infection. Taurine and AM could block the enhancement of Ica, Iout, and reduction of IKI after virus infection. Additionally, taurine and AM attenuated the increased expression level of LVDCCα1 subunit as well as Kv mRNA. Taurine and AM may exert their beneficial effect on VMC through modulating the changes in ion currents and expression. Drug Dev. Res. 58:57–60, 2003. © 2003 Wiley-Liss, Inc.

To investigate the effects of taurine and Astragalus membranaceus(AM) on ion currents and their expression in cardiomyocytes after Coxsackie virus B3 (CVB3) infection, hearts were removed from adult or newborn Sprague‐Dawley rats and digested by collagenase. CVB3 was inoculated to the medium and used for recording current of L‐type voltage‐dependent calcium channel (Ica), Na+current (INa), outward potassium current (Iout), and inward rectifying potassium current (IKI). An in vivo model of viral myocarditis (VMC) was produced by intraperitoneal injection of CVB3 into BALB/c mice and the hearts were used for examining the expression of L‐type voltage‐dependent Ca2+channel (LVDCC)α1 subunit and the voltage‐gated potassium channel (Kv). Icaand Ioutwere increased while IKIdecreased after inoculation with CVB3 for 2 h. However, INadid not differ between normal and infected cells. The positive hybridization signals of the LVDCCα1 subunit (antigen) and Kv1.2, Kv2.1, and Kv4.2 were much reinforced after CVB3 infection. Taurine and AM could block the enhancement of Ica, Iout, and reduction of IKIafter virus infection. Additionally, taurine and AM attenuated the increased expression level of LVDCCα1 subunit as well as Kv mRNA. Taurine and AM may exert their beneficial effect on VMC through modulating the changes in ion currents and expression. Drug Dev. Res. 58:57–60, 2003. © 2003 Wiley‐Liss, Inc.

Background Data on the association between physical activity and cardiovascular risk factors among populations with a relatively high level of physical activity such as the Chinese, are sparse. Methods In 1991, as part of the Sino-Shanghai Cardiovascular Disease Registry Project, a cross-sectional survey was performed in a random sample of 1206 residents, aged 35–64 years, living in rural Shanghai, China. Information on physical activity was obtained by questionnaire. The level of physical activity was categorized into low, moderate and high, based on the presence of a weekly frequency (<1, 1–2, ≥3) of periods of 20 minutes that cause shortness of breath, increase in pulse rate and perspiration. Body mass index (BMI), systolic (SBP) and diastolic blood pressure (DBP) level, serum lipids levels, smoking status and heart rate were assessed. Results Across groups with low, moderate and high levels of physical activity, significant inverse trends were found for hypertension, total cholesterol, BMI and heart rate in men, and for hypertension, SBP and DBP, BMI and heart rate in women. High density lipoprotein cholesterol and current smoking were not related to physical activity. When differences in BMI were allowed for, the associations between physical activity and hypertension and serum cholesterol in men, and with hypertension, SBP and DBP In women, were attenuated. Conclusions Our findings from a population-based survey In China suggest that a high level of physical activity is associated with favourable levels of some of the established cardiovascular risk factors in men and women.