ABSTRACT
<p><b>OBJECTIVE</b>To explore the predictive value of baseline plasma midregional fragment of pro-adrenomedullin level (MR-proADM) on long-term survival of postural tachycardia syndrome (POTS) children treated with midodrine hydrochloride.</p><p><b>METHODS</b>Fifty-three children (male 26, mean age (14.5 ± 4.5) years old) with POTS were included in this study, and all of them were diagnosed as POTS in our department from December 2007 to January 2010. Fifty-three children with POTS were divided into two groups according to the baseline plasma content of MR-proADM. Group I consisted of 35 POTS children with plasma content of MR-proADM > 61.5 ng/L, and the group II consisted of 18 POTS children with plasma content of MR-proADM ≤ 61.5 ng/L. The mean follow-up time was (67 ± 7) months. The orthostatic intolerance symptom score and the symptom free survival were compared between the 2 groups.</p><p><b>RESULTS</b>At the 60 months follow-up, the symptom score of children in group I was significantly lower than that in group II (χ(2) = 4.985, P < 0.05). At 72 months follow up, the symptom score was similar between the 2 groups (χ(2) = 0.004, P > 0.05) while the symptom free survival of group I was significantly higher than that in group II (χ(2) = 4.566, P < 0.05).</p><p><b>CONCLUSION</b>The baseline plasma MR-proADM level is value in predicting the long-term survival of POTS children treated with midodrine hydrochloride.</p>
Subject(s)
Adolescent , Child , Humans , Male , Adrenomedullin , Midodrine , Therapeutic Uses , Postural Orthostatic Tachycardia Syndrome , Diagnosis , Drug Therapy , ROC Curve , Vasoconstrictor Agents , Therapeutic UsesABSTRACT
<p><b>OBJECTIVE</b>To examine the effect of H2S donor, sodium hydrosulfide (NaHS), on ET-1 level in plasma and aorta in rats with atherosclerosis (AS).</p><p><b>METHOD</b>Thirty male rats, weighting 200-220 g, were randomly divided into AS, AS+NaHS and control groups, n = 10 in each group.Rats were given a single dose of vitamin D3 (700 000 U/kg) in the first three days and fed with a high-cholesterol diet for 8 weeks to induce AS. Rats in AS+NaHS group were intraperitoneally injected with an H2S donor NaHS, at a dose of 56 µmol/(kg·d) for 8 weeks. At the end of the experiment for 8 weeks, all the rats were sacrificed. The plasma was collected and the aorta and coronary tissues were isolated. The atherosclerotic lesions in both aorta and coronary arteries were detected using oil red O method. H2S concentration in plasma was determined with sulfide-sensitive electrode method. ET-1 levels in plasma and aorta were calculated by radioimmunoassay kit and the localization of ET-1 in the aorta was detected by immunohistochemistry. Plasma nitric oxide synthase (NOS), endothelial NOS (eNOS), inducible NOS (iNOS) were detected with colorimetry.</p><p><b>RESULT</b>AS plaque area in root of aorta of rats in AS group, AS+NaHS group and control group were (11.6±3.3)%, (1.6±1.1)%, (0.0±0.1)% respectively. The difference in AS plaque area in root of aorta among the three groups was statistically significant (F=97.675, P < 0.05). AS plaque area in coronary artery of rats in AS group, AS+NaHS group and control group were (21.4±5.7)%, (4.8±2.5)%, (0.0±0.0)% respectively. The difference in AS plaque area in coronary artery among the three groups was statistically significant (F=97.519, P < 0.05). Plasma H2S level in rats of AS group ((22.0±3.1) µmol/L) was significantly lower than that of control group ((27.9±1.0) µmol/L) and AS+NaHS group ((33.3±6.2) µmol/L, all P < 0.05). Compared with control group ((70.0±10.7) ng/L), plasma ET-1 in rats of AS group ((89.6±14.2) ng/L) and AS+NaHS group ((93.1±15.5) ng/L, P both < 0.05) were increased. However, there was no significant difference in plasma ET-1 content in rats between AS+NaHS group and AS group (P > 0.05). Compared with control group ((3.8±1.2) ng/g), ET-1 content in aorta in rats of AS group ((11.9±4.9) ng/g) and AS+NaHS group ((8.2±2.5) ng/g, both P < 0.05) were increased, and ET-1 content in aorta in rats of AS+NaHS group was decreased compared with AS group (P < 0.05). Immunochemistry results showed that ET expression in cytoplasm in aortic endothelial cells in rats of AS group was strengthened, while ET expression in rats of control group and AS+NaHS group was weak. NOS activity of rats in control group, AS group and AS+NaHS group was (25.4±5.6), (51.8±10.0) and (27.6±6.5) U/ml, eNOS activity (15.3±6.2), (4.5±2.7) and (8.7±3.9) U/ml, and iNOS activity (9.9±4.0), (47.3±10.7) and (19.0±5.2) U/ml, respectively.Differences among the three groups were statistically significant (NOS activity: F=37.231, P < 0.05, eNOS activity: F=14.600, P < 0.05, and iNOS activity: F=72.131, P < 0.05).</p><p><b>CONCLUSION</b>H2S donor NaHS reduced the AS plaque in AS rats. The mechanisms might involve the protective effect of H2S on the vascular endothelial cell, decreasing ET-1 production in aortal endothelium of atherosclerotic rats.</p>