[Research advances in the relationship between iron deficiency and neurodevelopment in preterm infants].

Iron deficiency (ID) is the most common micronutrient deficiency in children. Due to insufficient iron storage at birth and rapid catch-up growth after birth, preterm infants tend to have a high incidence rate of ID. During the critical period of brain development, ID alters iron-dependent neurometabolism, neurochemistry, neuroanatomy, and gene/protein profiles. This affects the central nervous system and causes the change in neurocognitive and behavioral development. Iron supplementation in infancy cannot reverse neurodevelopmental impairment caused by perinatal ID. The influence of ID on neurodevelopment is time- and region-specific, and in the high-risk population, early diagnosis and optimal iron treatment may help with the recovery of brain function and improve quality of life and long-term prognosis in preterm infants.

Mechanism of uncoupling protein 2­mediated myocardial injury in hypothermic preserved rat hearts.

In the present study, the alterations in uncoupling protein 2 (UCP2) expression following hypothermic preservation in rat hearts were investigated. Isolated rat hearts were preserved in Celsior solution for 3­12 h followed by 60 min of reperfusion. The cardiac function was evaluated using the Langendorff perfusion system. UCP2 and silent mating type information regulation 2 homolog 1 (SIRT1) proteins were detected by western blot analysis. The ATP production and mitochondrial reactive oxygen species (ROS) levels were assessed. Subsequent to preservation in ice­cold Celsior solution for 3­12 h, the UCP2 protein expression in rat hearts was observed to increase in a time­dependent manner. The UCP2 inhibitor genipin inhibited the hypothermic preservation­induced cardiac dysfunction, prevented a decline in ATP production induced by 9 h of preservation, however had no effect on the hypothermic preservation­induced increase in mitochondrial ROS levels. Compared with the control group, the SIRT1 protein expression in rat hearts reduced following hypothermic preservation. Compared with the 9­h preservation group, Celsior solution supplemented with the SIRT1 activator resveratrol (20 or 40 µmol/l) inhibited UCP2 protein overexpression, prevented the decline in ATP production and resulted in an improvement cardiac function. The SIRT1 inhibitor EX­527 abolished the resveratrol­induced inhibition of UCP2 overexpression and cardiac protection in the hypothermic preserved rat heart. These observations suggest that downregulation of UCP2 expression in the hypothermic preserved rat heart in part initiated the protective mechanism via the SIRT1 pathway.

Improved myocardial function with supplement of levosimendan to Celsior solution.

Levosimendan is a calcium-sensitizing agent shown to prevent myocardical contractile depression in various heart diseases. In this study, we investigated the effect of levosimendan on cardiac dysfunction and apoptosis in hypothermic preservation rat hearts. Isolated rat hearts were preserved in Celsior solution with or without levosimendan. The left ventricular developed pressure (LVDP) recovery rate of isolated rat heart significantly decreased, and the apoptosis index increased after 9 hours of hypothermic preservation. Supplement Celsior solution with levosimendan (10 and 10 mole/L) enhanced the LVDP recovery rate and reduced apoptosis. Levosimendan inhibited the hypothermic preservation-induced calpain activation and cleavage of Bid. Levosimendam induced increased myocardial inducible nitric oxide synthase but not endothelial nitric oxide synthase expression. A selective inducible nitric oxide synthase inhibitor 1400W, and a mitochondrial ATP-sensitive potassium (KATP) channel blocker 5-hydroxydecanoate but not a sarcolemmal KATP channel blocker HMR-1098 prevented improvement effect of levosimendam on LVDP recovery rate, abolished the inhibitory effect of levosimendan on hypothermic preservation-induced activation of calpain, cleavage of Bid, and apoptosis. These data suggested that Celsior solution supplement with levosimendan improved cardiac function recovery and reduced myocyte apoptosis in hypothermic preservation rat hearts.

Protective effects of the aqueous extract of Scutellaria baicalensis against acrolein-induced oxidative stress in cultured human umbilical vein endothelial cells.

CONTEXT: Scutellaria baicalensis Georgi (Labiatae) (SbG), one of the fifty fundamental herbs of Chinese herbology, has been reported to have anti-asthmatic, antifungal, antioxidative, and anti-inflammatory activities. OBJECTIVE: This study was designed to determine the protective effects of the extract of SbG against the acrolein-induced oxidative stress in cultured human umbilical vein endothelial cells (HUVEC). MATERIALS AND METHODS: The MTT reduction assay was employed to determine cell viability. The total cellular glutathione (GSH) level was detected using a colorimetric GSH assay kit. Cellular GSH production was conducted by detecting the mRNA expression levels of γ-glutamylcysteine ligase catalytic subunit and modifier subunit. RESULTS: Concentration-dependent cytotoxic effects of acrolein were observed while SbG could effectively protect the acrolein-induced oxidative damage. The protective mechanism was investigated, showing that the increased GSH content in the SbG-incubated HUVE cells was associated with the protective effects of SbG-treated cells. Further RT-PCR data confirmed the elevated mRNA expressions of GSH synthesis enzymes. DISCUSSION AND CONCLUSION: The current study strongly indicated that SbG could be a potential antioxidant against oxidative stress in treating cardiovascular diseases.

Complement activation by carotenoid derived aldehydes in cultured human vein epithelial cells.

This study was designed to determine the complement activation effects of carotenoid-derived aldehydes (CDA) on cultured human umbilical vein endothelial cells (HUVEC). A dose-dependent complement activation upon incubation of HUVEC with CDA was observed. Interestingly, the data showed that the alternative pathway was not activated. In addition, upon CDA treatment a significant number of apoptotic cells was also observed. The results revealed that CDA could activate the complement by way of the classical pathway. The study suggests that high carotenoid supplementation for the treatment of coronary heart disease should be used cautiously.

Puerarin protects against high glucose-induced acute vascular dysfunction: role of heme oxygenase-1 in rat thoracic aorta.

OBJECTIVE: To investigate the antioxidant and vascular protective effect of puerarin, an isoflavone glycoside known in traditional Chinese medicine on vascular reactivity subsequent to high glucose stress. METHODS: The thoracic aortic rings with or without endothelium from male SD rats were mounted in an organ bath. Isometric contraction of aortic rings was measured. HO-1 protein expression and HO activity were also evaluated. RESULTS: (1) After incubation with 44 mmol/L of high glucose for 2 or 4 h, the vascular contraction responses to phenylephrine (PE) and relaxation response to acetylcholine (Ach) decreased in an endothelium-dependent manner; (2) Coincubation with puerarin (10(-10)-10(-8) mol/L) and high glucose, the high glucose-induced vasoconstriction and vasodilation dysfunction was partly inhibited in a dose-dependent manner; (3) Puerarin increased the HO-1 protein expression and HO activity of thoracic aorta. ZnPP (an inhibitor of heme oxygenase-1) offset the protective effect of puerarin. CONCLUSION: Puerarin could alleviate the high glucose-induced acute endothelium-dependent vascular dysfunction in rat aortic rings. HO-1 activity was proposed as a mechanism to account for the protection of vascular responses by puerarin.

[Experimental studies on antiarrhythmic effect of jumi extraction].

AIM: To investigate the antiarrhythmic effect of jumi (JM) extraction. METHODS: The conventional antiarrhythmic methods were used. RESULTS: Administration of JM extraction reduced the occurrence of ventricular fibrillation induced by chloroform in a dose-dependent manner in mice. Quinidine significantly decreased the number of ventricular premature beats and ventricular tachycardia, shortened the duration of arrhythmia in aconitine-treated rats. But JM extraction had no effect on aconitine-induced arrhythmia. Compared with control, arrhythmia score was lower in ischemia/reperfusion rats which pretreated with 2.0 g/kg of JM extraction. CONCLUSION: JM extraction has obvious protection effects in chloroform- and ischemia-induced arrhythmia, but has no effect in aconitine-induced arrhythmia.

[Protective effect of mitochondrial ATP-sensitive potassium channel opener on rat heart during hypothermic preservation].

OBJECTIVE: To investigate whether the mitochondrial ATP-sensitive potassium channel (mitoK(ATP)) opener diazoxide as an additive to cardioplegia solution could enhance myocardial protection during hypothermic preservation of the rat heart. METHODS: The Langendorff model of isolated rat heart was used. After equilibrium, the hearts were stored in Celsior cardioplegia solution at 4 degree with or without supplement of diazoxide for 3 or 8 h followed by 60 minutes reperfusion. The recovery of cardiac contractile function, myocardial enzyme leakage in the coronary effluent, and myocardial water content were determined. The myocardial ultrastructure was also observed. RESULT: (1) Treatment of diazoxide improved the recovery of left ventricular developed pressure and decreased the leakage of myocardial enzymes, lactate dehydrogenase (LDH) and creatine kinase (CK), at the 2nd and 4th minute of reperfusion of rat heart after hypothermic preservation for 3 h. (2) After hypothermic preservation for 8 h, diazoxide improved the recovery of left ventricular developed pressure and decreased the leakage of myocardial enzymes (LDH, CK and glutamic oxalic transaminase) during reperfusion. Moreover, left ventricular end-diastolic pressure was significantly lower in diazoxide-treated hearts than that of hearts in Celsior solution. (3) Diazoxide significantly decreased the water content of myocardium and increased coronary flow of the hearts compared with those in control after hypothermic preservation for 8 h. (4) Impairment of myocardial ultrastructure after 8 h hypothermic preservation was alleviated in hearts treated with 30 mol/L diazoxide. (5) The cardiac effects of 30 mol/L diazoxide were attenuated by a mitoK(ATP) blocker 5-hydroxydecanoate (100 micromol/L). CONCLUSION: Diazoxide as a supplementation in cardioplegia solution could enhance myocardial protection during hypothermic heart preservation via opening of mitochondrial K(ATP) channel.

[The protective effect of diazoxide on long-term heart preservation].

Prolongation of the duration of heart preservation in vitro is very important in clinical heart transplantation. Previous studies have shown that mitochondrial ATP-sensitive potassium channel (mitoK(ATP)) plays an important role in cardioprotective effect. The purpose of this study was to assess whether the mitoK(ATP) opener diazoxide as an additive to cardioplegia solution could enhance myocardial protection during long-term hypothermic preservation of the rat heart. Langendorff model of isolated rat heart was used. After 30 min stabilization of perfusion, the hearts were stored in Celsior cardioplegia solution at 4 degrees C with (15, 30 and 45 micromol/L) or without diazoxide, a mitoK(ATP) channel opener, for 10 h followed by 60 min reperfusion. The recovery of cardiac contractile function, myocardial enzyme leakage in the coronary effluent, and myocardial water content were determined. The myocardial ultrastructure was also observed. We found that: (1) Diazoxide treatment improved the recovery of left ventricular developed pressure and +/-dp/dt(max) dose-dependently. Left ventricular end-diastolic pressure was significantly lower in diazoxide-treated hearts than that of hearts in Celsior solution after hypothermic preservation for 10 h. (2) Diazoxide at 30 and 45 micromol/L significantly decreased the water content of myocardium and increased coronary flow of the hearts compared to those in control. (3) The leakage of myocardial enzymes (lactate dehydrogenase, creatine kinase and glutamate-oxaloacetate transaminase) in the coronary effluent was significantly reduced in diazoxide-treated hearts. (4) Impairment of myocardial ultrastructure after 10 h hypothermic preservation was alleviated in hearts treated with 30 micromol/L diazoxide. (5) The cardiac effects of 30 micromol/L diazoxide were attenuated by a mitoK(ATP) blocker 5-hydroxydecanoate (5-HD, 100 micromol/L). These results indicate that diazoxide as a supplementation in cardioplegia solution could enhance myocardial protection during long-term hypothermic heart preservation via opening of mitochondrial K(ATP) channel.