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Although astragaloside IV, a saponin isolated from Astragalus membranaceus, has been shown to protect the myocardium against ischemia/reperfusion injury, its effect on the status of sarcoplasmic reticulum (SR) Ca2+ transport in the injured myocardium remains largely unknown. In this study, we investigated whether in cultured cardiomyocytes subjected to hypoxia and reoxygenation (H/R) administration of astragaloside IV during H/R attenuates the myocardial cell injury and prevents changes in Ca2+ handling activities and gene expression of SR Ca2+ pump. Cultured cardiomyocytes from neonatal rats were exposed to 6 h of hypoxia followed by 3 h of reoxygenation. Myocyte injury was determined by the release of cardiac troponin I in supernatant. Astragaloside IV significantly inhibited cardiac troponin I release after H/R in a dose-dependent manner. The diastolic [Ca2+]i measured with Fura-2/AM was significantly increased after reoxygenation. Astragaloside IV prevented the rise of diastolic [Ca2+]i and the depression of caffeine-induced Ca2+ transients caused by H/R. Furthermore, the observed depressions in SR Ca2+-ATPase activity as well as the mRNA and protein expression of SR Ca2+-ATPase in hypoxic-reoxygenated cardiomyocytes were attenuated by astragaloside IV treatment. These results suggest that the beneficial effect of astragaloside IV in H/R-induced injury may be related to normalization of SR Ca2+ pump expression and, thus, may prevent the depression in SR Ca2+ handling. Copyright © 2008 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

We have extracted and roughly purified astragalosides (AS) from Astragalus membranaceus, a natural herb used as a traditional Chinese medicine, regarded to have pharmacodynamic benefits of protecting injured myocardium. We hypothesized that the astragalosides might exert beneficial effect in myocardial lesion by preserving both energy metabolism and Ca2+ homeostasis. Sprague-Dauley (SD) rats were injected with isoproterenol (ISO) subcutaneous (s.c.) at a dose of 5 mg/kg/day consecutively for two days as models and were treated with astragalosides and trimetazidine intraperitoneally (i.p.) respectively, at a dose of 5 mg/kg/day one day prior to isoproterenol for 8 days. The histological changes were alleviated in isoproterenol-injected SD rats treated with astragalosides. Compared with isoproterenol-injected rats, the concentration of myocardial intracellular [Ca2+]i was decreased, L-type Ca2+ current density and sarcoplasmic reticulum (SR) Ca2+ load were recovered, the concentration of myocardial ATP was increased and phosphocreatine (PCr) was decreased in rats treated with astragalosides. In conclusion, the efficacious treatment of astragalosides for myocardial injury might be through regulating intracellular Ca2+ homeostasis and energy metabolism. [ABSTRACT FROM AUTHOR]

In clinical practice, Astragali Radix (Astragalus), the root of Astragalus membranaceus Bunge, has been widely applied to treat patients with viral diseases, including viral myocarditis in China. The present study was designed to evaluate the protective effects of Astragalus on the function of sarcoplasmic reticulum calcium ATPase (SERCA2) activity and endothelin system at acute and chronic periods of myocarditis mice induced by CVB3 infection. Astragalus feeding (2.2 mg/kg/day) could significantly increase the survival rate, alleviate pathological alterations and serum cardiac troponin I (cTnI), as well as restore impaired SERCA activity at the acute stage. Low affinity and capacity of ETR were reversed with Astragalus after the first CVB3 inoculation up to 7 days and after the second virus inoculation up to 150 days. In the meantime, the contents of cardiac ET-1 and ANP were reduced. Comparison the myocarditis mice treated with Perindopril (0.44 mg/kg/day), an ACE inhibitor, shows that Astragalus achieved a similar effect on survival rate, SERCA2 and ET system. These results indicated that the beneficial effects of Astragalus and Perindopril for treating viral myocarditis might be partly mediated by preserving the functions of SERCA 2 activity and ET system. [ABSTRACT FROM AUTHOR]

Dysregulation of intracellular Ca2+ homeostasis plays an important role in mediating myocardial injury. We tested the hypothesis that treatment with trimetazidine (TMZ) would improve intracellular Ca2+ handling in myocardial injury of rats. The control group received saline only (10 ml kg−1 day−1,i.p.) for 7 days. In a second group, isoprenaline (ISO; 5 mg kg−1 day−1,s.c.) was administered to rats for 2 days to induce an acute injury of the myocardium. In a third group, treatment with TMZ (10 mg kg−1 day−1,i.p.) was initiated 1 day before ISO administration and continued for 7 days ( n= 7 rats in each group). Histopathological evaluation showed that TMZ prevented ISO-induced myocardial damage. TMZ preserved the ATP levels and decreased the maleic dialdehyde (MDA) content in the hearts compared with ISO-treated rats. The diastolic [Ca2+]i measured by loading with fura-2 AM in isolated cardiomyocytes was increased significantly in ISO-treated rats compared to the control animals. TMZ prevented the rise of diastolic [Ca2+]i and the depression of caffeine-induced Ca2+ transients caused by ISO administration. The reduction in sarcoplasmic reticulum (SR) Ca2+ content in the heart cells and in cardiac SR Ca2+-ATPase activity in ISO-treated rats was abolished by TMZ, although there were no differences in SR Ca2+-ATPase protein levels between the control, ISO and ISO + 7 mz-treated rats. In addition, TMZ prevented the reduction in sarcolemmal L-type Ca2+ current density in the heart cells induced by ISO treatment. These results demonstrate that the treatment of rats with TMZ inhibited the increase of diastolic [Ca2+]i and prevented the decrease of SR Ca2+ content, SR Ca2+-ATPase activity and L-type Ca2+ current density in cardiomyocytes in ISO-mediated myocardial injury of rats. These changes in Ca2+ handling could help to explain the favourable action of TMZ in myocardial injury. [ABSTRACT FROM AUTHOR]

Astragalosides were the main active components from a native Chinese herb Astragalus membranaceus. Recent studies have shown that Astragalosides have a protective effect on myocardial injury in rats. The present study was designed to investigate the effect of Astragalosides on intracellular calcium overload and sarcoplasmic reticulum calcium load (SR Ca2+ load) in cultured cardiac myocytes from neonatal rats. Astragalosides (100 μg/ml) were incubated in the presence of isoproterenol (ISO) (10-5 M) for 72 hours in cardiomyocytes. Metoprorol (10-6 M), a β1-selective antagonist, was cultured in the same condition as Astragalosides. The result showed that intracellular calcium concentration ([Ca2+]i) and SR Ca2+ load increased in ISO-treated cardiac myocytes as compared to control (P<0.01). Astragalosides prevented ISO-induced increase in [Ca2+]i and SR Ca2+ load. Metoprolol also inhibited those increase. The mRNA expression and activity of sarcoplasmic reticulum Ca2+ ATPase (SERCA) were enhanced following ISO treatment in cardiac myocytes, and these increases were inhibited by Astragalosides or metoprolol (P<0.05). The decrease of superoxide dismutase (SOD) activity and the elevation of intracellular maleic dialdehyde (MDA) were observed after ISO treatment in cardiac myocytes. Both Astragalosides and metoprolol restored the SOD activity and reduced the level of MDA. We conclude that Astragalosides have the effects on reducing [Ca2+]i and SR Ca2+ load, enhancing free radical removal and decreasing lipid peroxidation in ISO-treated cardiomyocytes, which might account for their protective effect on myocardial injury. [ABSTRACT FROM AUTHOR]

The present study was designed to determine whether or not an increase in endothelial intracellular concentration of calcium ([Ca2+]i) evokes endothelium-dependent contractions in the aorta from normotensive Wistar-Kyoto (WKY) and spontaneously hypertensive rats (SHR). Acetylcholine, adenosine triphosphate (ATP) and the calcium ionophore, A 23187, produced endothelium-dependent relaxations in isolated aortic rings of both WKY and SHR. These relaxations in response to the three agonists were significantly smaller in the SHR when compared with the WKY. Endothelium-dependent contractions to acetylcholine, ATP and A 23187 were observed only in the aorta isolated from the SHR. In the presence of NG-nitro-L-arginine, an NO synthase inhibitor, the endothelium-dependent contractions in response to acetylcholine, ATP and A 23187 were potentiated significantly in the aorta SHR and were unmasked in that of WKY. However, the contractions were still significantly greater in SHR than in WKY. These contractions were abolished by indomethacin and valeryl salicylate (two cyclo-oxygenase inhibitors) as well as by S 18886 (a TP-receptor antagonist), indicating that the endothelium-dependent contraction produced by the three agonists share the same characteristics. The results of the present study indicate that the release/generation of endothelium-derived contracting factor, requires an increase in endothelial [Ca2+]i. [ABSTRACT FROM AUTHOR]

1 Experiments were designed to investigate whether or not oxygen-derived free radicals mediate endothelium-dependent contractions to acetylcholine in the aorta of spontaneously hypertensive rat (SHR). 2 Isometric tension was measured in aortic rings taken from adult male SHR and Wistar-Kyoto rat (WKY) in the presence of N[supG]-nitro-i-arginine. 3 Endothelium-dependent contractions to acetylcholine were significantly greater in rings from SHR compared to WKY. Oxygen-derived free radicals, generated from van thine plus xanthine oxidase, induced contractions that were larger in aortas from SHR than from WKY. Contractions to acetylcholine and tree radicals were abolished by a selective TP-receptor antagonist, S 18886, and a preferential inhibitor of cyclo-oxygenase-l, valeryl salicylate. but not by a preferential inhibitor of cyclo-oxygenase-2, NS-398. 4 Allopurinol, deferoxainine and the combination of superoxide dismutase plus catalase inhibited the contractions to oxygen-derived free radicals but did not significantly affect those to acetylcholine. In contrast, diethyldithiocarbamic acid, an inhibitor of superoxide dismutase. or Tiron, a scavenger of superoxide anion, reduced endothelium-dependent contractions to acetylcholine in aortas from SHR. The died of these two drugs was additive. 5 In SHR chronically treated with dimethylthiourea endothelium-dependent contractions to acetylcholine were decreased, and reduced further by acute in vitro exposure to deferoxamine or the combination of superoxide dismutase plus catalase. 6 These results suggest that in the SHR aorta acetylcholine-induced endothelium-dependent contractions involve endothelial superoxide anion production and the subsequent dismutation into hydroxyl radicals and or hydrogen peroxide. The free radicals activate cyclo-oxygenase-1 most likely to produce endoperoxides. Activation of TP-receptors is required to observe endothelium-dependent contractions to acetylcholine or endothelium-independent contractions in response to free radical generation. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the ability of computer-aided diagnosis (CAD) system (S-Detect) to identify malignancy in ultrasound (US) -detected BI-RADS 3 breast lesions., Materials and Methods: 148 patients with 148 breast lesions categorized as BI-RADS 3 were included in the study between January 2021 and September 2022. The malignancy rate, accuracy, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and area under the curve (AUC) were calculated., Results: In this study, 143 breast lesions were found to be benign, and 5 breast lesions were malignant (malignancy rate, 3.4 %, 95 % confidence interval (CI): 0.5-6.3). The malignancy rate rose significantly to 18.2 % (4/22, 95 % CI: 2.1-34.3) in the high-risk group with a "possibly malignant" CAD result (p = 0.017). With a "possibly benign" CAD result, the malignancy rate decreased to 0.8 % (1/126, 95 % CI: 0-2.2) in the low-risk group (p = 0.297). The AUC, sensitivity, specificity, accuracy, PPV, and NPV of the CAD system in BI-RADS 3 breast lesions were 0.837 (95 % CI: 77.7-89.6), 80.0 % (95 % CI: 73.6-86.4), 87.4 % (95 % CI: 82.0-92.7), 87.2 % (95 % CI: 81.8-92.6), 18.2 % (95 % CI: 2.1-34.3) and 99.2 % (95 % CI: 97.8-100.0), respectively., Conclusions: CAD system (S-Detect) enables radiologists to distinguish a high-risk group and a low-risk group among US-detected BI-RADS 3 breast lesions, so that patients in the low-risk group can receive follow-up without anxiety, while those in the high-risk group with a significantly increased malignancy rate should actively receive biopsy to avoid delayed diagnosis of breast cancer., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors.)

Objectives: This study aimed to evaluate the potential role of hydrogen in rats after cerebral ischemic/reperfusion (I/R) injury., Materials and Methods: The experimental samples were composed of sham group, model group of rats that received middle cerebral artery occlusion (MCAO) for 2 hr followed by reperfusion for 24 hr, and the hydrogen saline group treated by hydro¬gen-rich saline (1 ml/kg) after MCAO. Hydrogen sulfide (H2S), S100-βprotein (S100-β), and neuron-specific enolase (NSE) levels were measured; the levels of malondialdehyde (MDA), reactive oxygen species (ROS), and superoxide dismutase (SOD) were detected; the histologic structure and apoptotic cells of hippocampus were observed; the expressions of cystathionine β-synthase (CBS), nuclear factor erythroid 2-related factor 2 (Nrf2), and hemeoxygenase-1 (HO-1) were measured. Statistical analyses were performed using one-way analysis of variance (ANOVA) followed by Fisher's least significant difference (LSD) test., Results: Our results showed that hydrogen up-regulated H2S levels via promoting the expression of CBS in the hippocampus, and its treatment alleviated oxidative stress via activating the expression of Nrf2 and HO-1, and then cell apoptosis reduced, furthermore, brain function improved by down-regulating the levels of S100-βand NSE., Conclusion: This study showed that hydrogen-rich saline ameliorates cell injury through up-regulating the expression of CBS in the hippocampus after cerebral ischemia reperfusion (I/R) in rats, this provides new experimental evidence for the treatment of stroke with hydrogen saline.

Background: To investigate the CT manifestations of primary cardiac angiosarcoma., Methods: The clinical and CT data for 9 patients with cardiac angiosarcoma were retrospectively analyzed., Results: The lesions in all nine cases were located in the right atrium. In two cases, the involved lesion led downward to the tricuspid valve and right ventricle, and the dynamic cine showed that the lesion affected the opening and closing of the tricuspid valve. In three cases, the lesion involvement led to a thickened pericardium, accompanied by pericardial effusions. On CT plain scans, six patients showed homogeneous density, while three showed inhomogeneous density, two of which were associated with bleeding. On enhanced CT scans, seven patients showed heterogeneous centripetal enhancement, and some angiograms showed lesions with tortuous small blood vessels. The remaining two cases showed early stage rapid inhomogeneous enhancement. Five cases showed multiple metastatic nodules in the lungs at the time of initial diagnosis; four of these showed distinct sharp edges in multiple pulmonary nodules., Conclusions: Cardiac angiosarcoma has a predilection site and is prone to invading adjacent structures, manifesting as malignant pericardial and pleural effusions. The CT enhancement manifestations are mostly inhomogeneous and centripetal with ground-glass opacity peripheral to the intrapulmonary metastases.