In summary, dysfunction of the vascular H2S synthase/H2S pathway was found in l-NAME-induced hypertensive rats. Exogenous H2S effectively prevented the development of hypertension induced by l-NAME. These findings suggest that the H2S synthase/H2S pathway participates in hypertension.

Objective: Hydrogen sulfide (H₂S), an endogenous gaseous transmitter, was found to protect the heart from various forms of injury, but the underlying mechanism is not known. H₂S can open the K_ATP channel on vascular smooth muscle cells, and the objective of this study was to determine whether H₂S can open the K_ATP channel on myocardiocytes. Methods: The whole-cell patch-clamp technique was used to record I_K,ATP and action potentials of atrial and ventricular myocytes isolated from the hearts of male Wistar rats. Sodium hydrogen sulfide (NaHS) was used as a donor of H₂S to observe the effect of exogenous H₂S on I_K,ATP. DL-propargylglycine (PPG), an inhibitor of the synthesis of H₂S, was used at a concentration of 200 µM to observe the effect of endogenous H₂S on I_K,ATP. Results: NaHS at concentrations (in µM) of 9.375, 18.75, 37.5, 75 and 150 increased I_K,ATP by 12.8% (p > 0.05), 28.4% (p < 0.05), 38.8% (p < 0.01), 51.2% (p < 0.01) and 58.6% (p< 0.01) on ventricular myocytes, respectively, and by 6.8% (p > 0.05), 10.4% (p > 0.05), 18.9% (p < 0.01), 24.8% (p < 0.01) and 37.2% (p < 0.01) on atrial myocytes, respectively. The H₂S-induced decrease in the duration of action potentials (APD₉₀) of ventricular myocytes was concentration-dependent, although only NaHS at a concentration of 150 µM decreased the APD₉₀ significantly (15%, p < 0.05). The H₂S-induced decrease in APD₉₀ on atrial myocytes was concentration dependent, but the statistical difference was not significant. Inhibition of I_K,ATP by PPG was time dependent and the level of inhibition was: ventricular myocytes, 7% (p > 0.05), 10% (p < 0.05), 15.3% (p < 0.01), 24.0% (p < 0.01) and 28.9% (p < 0.01); atrial myocytes, 15.8% (p > 0.05), 21.3% (p > 0.05), 26.5% (p < 0.01), 34.0% (p < 0.01) and 43.2% (p < 0.01) measured at 5, 10, 15, 20 and 25 min, respectively. The increase in the APD₉₀, by PPG was time dependent for ventricular myocytes [increased by 12.8% (p < 0.05) at 25 min]. The same was true for atrial myocytes, although only the value at 25 min was significant (15%, p < 0.05). Conclusions: H₂S decreased the APD₉₀,and both the endogenous and exogenous H₂S-induced increase in I_K,ATP on both atrial and ventricular myocytes was concentration dependent. These results may help to explain, at least in part, how H₂S protects heart cells from various forms of injury.

Both activities of daily living (ADL) and some blood biomarkers (such as albumin) have been associated with mortality in very elderly people, but scarce data is available on the predictive performance of them in isolation or in combination, which is important for clinicians in decision making. Here, based on prospective mortality data over a 6-year follow-up period from 433 long-lived individuals (LLIs) aged 95+ years in the Rugao longevity cohort, we aimed to evaluate Cox proportional hazard ratios (HRs) and discriminative power (ROC curve) of 14 biomarkers and ADL for all-cause mortality. We found that six biomarkers (total triglyceride, albumin, low-density lipoprotein cholesterol, platelet count, lymphocyte count, and neutrophil count) were associated with mortality with a p < .10 in the univariate model. Significant associations of albumin and neutrophil count with mortality were observed when they were simultaneously included in a multivariate model, with HRs of 0.97 (95 % CI 0.94, 0.99; p = .005) and 1.09 (95 % CI 1.00, 1.18; p = .043). With respect to ADL, the corresponding HR was 1.10 (95 % CI 1.07, 1.14; p < .001). Low albumin (<40 g/L) combined with ADL dependent had a significantly increased mortality risk (HR = 2.19; 95 % CI 1.63, 2.95). Albumin and ADL separately showed good discriminative accuracies (area under the curve [AUC] = 0.68 and 0.66, respectively), and their combination had an increased predictive utility (AUC = 0.73). In conclusion, both albumin and ADL are efficient predictors of all-cause mortality in long-lived populations and their combination further increases discriminative power. The preliminary findings, if validated and translated, would help clinicians to identify the elderly people at varying mortality risk.

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—Arrhythmia is a big headache for cardiologist for a long time. A new antiarrythmic drug with good effects and few side effects should be explored. Hydrogen sulfide, a newly found gaseous transmitter, was found to have multi-effects on a variety of ion channels. It may be a promising antiarrythmic drug. This article reviews the different effects of hydrogen sulfide on different ion channels.

We studied the effects of cobalt-60 Gamma-radiation on the gene expression and secretion of adrenomedullin (Adm) and endothelin (ET) in cultured rat vascular smooth muscle cells (VSMCs). Rat VSMCs cultured in Dulbecoo's modified Eagle's medium containing 10% FBS were radiated with cobalt-60 Gamma-radiation at doses of 1, 14, and 25 Gy, respectively. Then the mRNA of Adm and ET in VSMCs were detected by the reverse-transcriptative competitive polymerase chain reaction. Adm and ET levels in rat VSMCs were measured by radioimmunoassay. As compared with that of the control, the secretions of Adm in rat VSMCs radiated at doses of 14 and 25 Gy were increased by 270% (P < 0.05) and 233% (P < 0.05), respectively. The mRNA levels of Adm were increased by 82.4% (P < 0.01) and 101% (P <0.01), respectively. Meanwhile, the secretions of ET were decreased by 27.3% (P < 0.01) and 58.0% (P < 0.01) in VSMCs radiated at doses of 14 and 25 Gy, respectively. In parallel, the mRNA levels of ET were decreased by 47.1% (P < 0.01) and 40.2% (P < 0.01), respectively. Radiation at a dose of 1 Gy had no significant effect on Adm and ET at the gene and protein levels. As compared with the control, the Adm/ET ratios in VSMCs increased by 65% (P > 0.05), 409% (P < 0.01), and 693% (P < 0.01), respectively, with radiation at doses of 1,14 and 25 Gy, respectively. The balance of Adm/ET in VSMCs could be changed by cobalt-60 Gamma-radiation, which might play an important role in the use of radiotherapy for restenosis.

Atrial fibrillation (AF) is the most common arrhythmia. It is associated with increased stroke risks, thromboembolism, and other complications, which are great life and economic burdens for patients. In recent years, with the maturity of percutaneous catheter radiofrequency ablation (RFA) technology, it has become a first-line therapy for AF. However, some patients still experience AF recurrence (AFR) after RFA, which can cause serious consequences. Therefore, it is crucial to identify appropriate parameters that can predict the prognosis. Here, we reviewed possible predicting indicators for AFR, focusing on all the electrocardiogram indicators, such as P wave duration, PR interval and so on. It may provide valuable information for guiding clinical works.