H2S increased vascular SUR2B and Kir6.1 expression of SHR, promoting vasorelaxation. H2S antagonized ET-1-inhibited KATP expression in A7r5 cells and cultured ASMCs. H2S inhibited ET-1-induced FOXO1 and FOXO3a phosphorylation in ASMCs. H2S promoted FOXO1 and FOXO3a nuclear translocation and binding with target gene promoters.

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ObjectiveWe aimed to determine upright heart rate and blood pressure (BP) changes to suggest diagnostic criteria for postural orthostatic tachycardia syndrome (POTS) and orthostatic hypertension (OHT) in Chinese children.MethodsIn this cross-sectional study, 1449 children and adolescents aged 6–18 years were randomly recruited from two cities in China, Kaifeng in Henan province and Anguo in Hebei province. They were divided into two groups: 844 children aged 6–12 years (group I) and 605 adolescents aged 13–18 years (group II). Heart rate and BP were recorded during an active standing test.Results95th percentile (P95) of δ heart rate from supine to upright was 38 bpm, with a maximum upright heart rate of 130 and 124 bpm in group I and group II, respectively. P95 of δ systolic blood pressure (SBP) increase was 18 mm Hg and P95 of upright SBP was 132 mm Hg in group I and 138 mm Hg in group II. P95 of δ diastolic blood pressure (DBP) increase was 24 mm Hg in group I and 21 mm Hg in group II, and P95 of upright DBP was 89 mm Hg in group I and 91 mm Hg in group II.ConclusionsPOTS is suggested when δ heart rate is ≥38 bpm (for easy memory, ≥40 bpm) from supine to upright, or maximum heart rate ≥130 bpm (children aged 6–12 years) and ≥125 bpm (adolescents aged 13–18 years), associated with orthostatic symptoms. OHT is suggested when δ SBP (increase) is ≥20 mm Hg, and/or δ DBP (increase) ≥25 mm Hg (in children aged 6–12 years) or ≥20 mm Hg (in adolescents aged 13–18 years) from supine to upright; or upright BP≥130/90 mm Hg (in children aged 6–12 years) or ≥140/90 mm Hg (in adolescents aged 13–18 years).

The authors investigated the regulatory effects of sulfur dioxide (SO2) on myocardial injury induced by isopropylarterenol (ISO) hydrochloride and its mechanisms. Wistar rats were divided into four groups: control group, ISO group, ISO plus SO2 group, and SO2 only group. Cardiac function was measured and cardiomyocyte apoptosis was detected. Bcl-2, bax and cytochrome c (cytc) expressions, and caspase-9 and caspase-3 activities in the left ventricular tissues were examined in the rats. The opening status of myocardial mitochondrial permeability transition pore (MPTP) and membrane potential were analyzed. The results showed that ISO-treated rats developed heart dysfunction and cardiac injury. Furthermore, cardiomyocyte apoptosis in the left ventricular tissues was augmented, left ventricular tissue bcl-2 expression was down-regulated, bax expression was up-regulated, mitochondrial membrane potential was significantly reduced, MPTP opened, cytc release from mitochondrion into cytoplasm was significantly increased, and both caspase-9 and caspase-3 activities were increased. Administration of an SO2 donor, however, markedly improved heart function and relieved myocardial injury of the ISO-treated rats; it lessened cardiomyocyte apoptosis, up-regulated myocardial bcl-2, down-regulated bax expression, stimulated mitochondrial membrane potential, closed MPTP, and reduced cytc release as well as caspase-9 and caspase-3 activities in the left ventricular tissue. Hence, SO2 attenuated myocardial injury in association with the inhibition of apoptosis in myocardial tissues, and the bcl-2/cytc/caspase-9/caspase-3 pathway was possibly involved in this process.

Postural orthostatic tachycardia syndrome (POTS) is common, and has a serious impact on children's quality of life. Midodrine hydrochloride, an α1-adrenoreceptor agonist, is an effective treatment. The study was designed to examine the therapeutic efficacy of midodrine hydrochloride by quantifying changes in blood pressure during the head-up test (HUT), in children with POTS. Overall, 104 out of 110 children with POTS were treated with midodrine hydrochloride and successfully followed-up. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) changes were analyzed during the HUT. In a retrospective analysis, a receiver operating characteristic (ROC) curve was used to analyze the therapeutic predictive value of pre-treatment changes in SBP, DBP, and a combination of both, from the supine position to standing, in the subjects. The increase of SBP and DBP from the supine position to standing in responders were significantly lower than that of the non-responders. The ROC curve showed that midodrine hydrochloride for children with POTS would be predicted to be effective when the pre-treatment increase of SBP was ≤ 0 mmHg, or when the pre-treatment increase of DBP was ≤ 6.5 mmHg (from the supine position to standing), yielding a sensitivity of 72% and specificity of 88%. The area under the curve was 0.744 and 0.809, respectively. Hence, the results suggested that looking at the changes in blood pressure during the HUT was useful in predicting the response to midodrine hydrochloride in children with POTS.