OBJECTIVETo investigate the protective effect of heat shock protein 70 (HSP70) against hypoxic pulmonary hypertension (HPH) in neonatal rats.

METHODSA total of 128 neonatal rats were randomly divided into blank control group, HPH model group, empty virus group, and HSP70 group, with 32 rats in each group. Before the establishment of an HPH model, the rats in the blank control group and HPH model group were given caudal vein injection of 5 μL sterile saline, those in the empty virus group were given caudal vein injection of 5 μL Ad-GFP (1 010 PFU/mL), and those in the HSP70 group were given caudal vein injection of 5 μL Ad-HSP70 (1 010 PFU/mL). HPH model was prepared in the HPH model, empty virus, and HSP70 groups after transfection. At 3, 7, 10, and 14 days after model establishment, a multi-channel physiological recorder was used to record mean pulmonary arterial pressure (mPAP), optical and electron microscopes were used to observe the structure and remodeling parameters of pulmonary vessels, and Western blot was used to measure the protein expression of HSP70, hypoxia-inducible factor-1α (HIF-1α), endothelin-1 (ET-1), and inducible nitric oxide synthase (iNOS) in lung tissues.

RESULTSAt 3, 7, 10, and 14 days after model establishment, the HPH model group and the empty virus group had a significantly higher mPAP than the blank control group (P<0.05). On days 7 and 10 of hypoxia, the blank control group and the HSP70 group had significantly lower MA% and MT% than the HPH model group and the empty virus group (P<0.01); on day 14 of hypoxia, the HPH model group, empty virus group, and HSP70 group had similar MA% and MT% (P>0.05), but had significantly higher MA% and MT% than the blank control group (P<0.01). On days 3, 7 and 10 of hypoxia, the HSP70 group had significantly higher protein expression of HSP70 than the HPH model group, empty virus group, and blank control group (P<0.01); the HSP70 group had significantly lower expression of HIF-1α, ET-1, and iNOS than the HPH model group and the empty virus group (P<0.05) and similar expression of HIF-1α, ET-1, and iNOS as the blank control group (P>0.05).

CONCLUSIONSIn neonatal rats with HPH, HSP70 transfection can increase the expression of HSP70 in lung tissues, downregulate the expression of HIF-1α, ET-1, and iNOS, alleviate pulmonary vascular remodeling, and reduce pulmonary artery pressure; therefore, it may become a new strategy for the treatment of HPH in neonates.

Animals ; Disease Models, Animal ; Endothelin-1 ; analysis ; HSP70 Heat-Shock Proteins ; genetics ; physiology ; Hypertension, Pulmonary ; prevention & control ; Hypoxia ; complications ; Hypoxia-Inducible Factor 1, alpha Subunit ; analysis ; Nitric Oxide Synthase Type II ; analysis ; Pulmonary Artery ; pathology ; Rats ; Rats, Wistar ; Transfection

OBJECTIVETo investigate the association between pulmonary vascular remodeling and expression of hypoxia-inducible factor-1α (HIF-1α), endothelin-1 (ET-1) and inducible nitric oxide synthase (iNOS) in pulmonary vessels in neonatal rats with hypoxic pulmonary hypertension (HPH).

METHODSA neonatal rat model of HPH was established as an HPH group, and normal neonatal rats were enrolled as a control group. The mean pulmonary arterial pressure (mPAP) was measured. The percentage of medial thickness to outer diameter of the small pulmonary arteries (MT%) and the percentage of medial cross-section area to total cross-section area of the pulmonary small arteries (MA%) were measured as the indicators for pulmonary vascular remodeling. The immunohistochemical reaction intensities for HIF-1α, ET-1 and iNOS and their mRNA expression in lung tissues of neonatal rats were measured. Correlation analysis was performed to determine the relationship between pulmonary vascular remodeling and mRNA expression of HIF-1α, ET-1 and iNOS.

RESULTSThe mPAP of the HPH group kept increasing on days 3, 5, 7, 10, 14, and 21 of hypoxia, with a significant difference compared with the control group (P<0.05). The HPH group had significantly higher MT% and MA% than the control group from day 7 of hypoxia (P<0.05). HIF-1α protein expression increased significantly on days 3, 5, 7 and 10 days of hypoxia, and HIF-1α mRNA expression increased significantly on days 3, 5 and 7 days of hypoxia in the HPH group compared with the control group (P<0.05). ET-1 protein expression increased significantly on days 3, 5 and 7 days of hypoxia and ET-1 mRNA expression increased significantly on day 3 of hypoxia in the HPH group compared with the control group (P<0.05). Both iNOS protein and mRNA expression were significantly higher on days 3, 5 and 7 days of hypoxia than the control group (P<0.05). Both MT% and MA% were positively correlated with HIF-1α mRNA expression (r=0.835 and 0.850 respectively; P<0.05).

CONCLUSIONSPulmonary vascular remodeling is developed on day 7 of hypoxia in neonatal rats. HIF-1α, ET-1 and iNOS are all involved in the occurrence and development of HPH in neonatal rats.

Animals ; Animals, Newborn ; Endothelin-1 ; analysis ; physiology ; Hypertension, Pulmonary ; etiology ; metabolism ; pathology ; Hypoxia ; complications ; Hypoxia-Inducible Factor 1, alpha Subunit ; analysis ; physiology ; Immunohistochemistry ; Nitric Oxide Synthase Type II ; analysis ; physiology ; Pulmonary Artery ; chemistry ; pathology ; Rats ; Rats, Wistar

OBJECTIVEBased on the observation that coagulation necrosis occurs in the majority of neonatal necrotizing enterocolitis (NEC) patients, it is clear that intestinal ischemia is a contributing factor to the pathogenesis of NEC. However, the published studies regarding the role of intestinal ischemia in NEC are controversial. The aim of this paper is to review the current studies regarding intestinal microcirculatory dysfunction and NEC, and try to elucidate the exact role of intestinal microcirculatory dysfunction in NEC.

DATA SOURCESThe studies cited in this review were mainly obtained from articles listed in Medline and PubMed. The search terms used were "intestinal microcirculatory dysfunction" and "neonatal necrotizing enterocolitis".

STUDY SELECTIONMainly original milestone articles and critical reviews written by major pioneer investigators in the field were selected.

RESULTSImmature regulatory control of mesentery circulation makes the neonatal intestinal microvasculature vulnerable. When neonates are subjected to stress, endothelial cell dysfunction occurs and results in vasoconstriction of arterioles, inflammatory cell infiltration and activation in venules, and endothelial barrier disruption in capillaries. The compromised vasculature increases circulation resistance and therefore decreases intestinal perfusion, and may eventually progress to intestinal necrosis.

CONCLUSIONIntestinal ischemia plays an important role through the whole course of NEC. New therapeutic agents targeting intestinal ischemia, like HB-EGF, are promising therapeutic agents for the treatment of NEC.

Endothelin-1 ; physiology ; Endothelium, Vascular ; physiopathology ; Enterocolitis, Necrotizing ; drug therapy ; etiology ; pathology ; Heparin-binding EGF-like Growth Factor ; Humans ; Infant, Newborn ; Intercellular Signaling Peptides and Proteins ; therapeutic use ; Intestines ; blood supply ; Ischemia ; complications ; Microcirculation ; physiology ; Nitric Oxide ; physiology ; Splanchnic Circulation

Echinomycin is a small-molecule inhibitor of hypoxia-inducible factor-1 DNA-binding activity, which plays a crucial role in ovarian ovulation in mammalians. The present study was designed to test the hypothesis that hypoxia-inducible factor (HIF)-1alpha-mediated endothelin (ET)-2 expressions contributed to ovarian ovulation in response to human chorionic gonadotropin (hCG) during gonadotropin-induced superuvulation. By real-time RT-PCR analysis, ET-2 mRNA level was found to significantly decrease in the ovaries after echinomycin treatment, while HIF-1alpha mRNA and protein expression was not obviously changed. Further analysis also showed that these changes of ET-2 mRNA were consistent with HIF-1 activity in the ovaires, which is similar with HIF-1alpha and ET-2 expression in the granulosa cells with gonadotropin and echinomycin treatments. The results of HIF-1alpha and ET-2 expression in the granulosa cells transfected with cis-element oligodeoxynucleotide (dsODN) under gonadotropin treatment further indicated HIF-1alpha directly mediated the transcriptional activation of ET-2 during gonadotropin-induced superuvulation. Taken together, these results demonstrated that HIF-1alpha-mediated ET-2 transcriptional activation is one of the important mechanisms regulating gonadotropin-induced mammalian ovulatory precess in vivo.
Animals ; Cells, Cultured ; Chorionic Gonadotropin/*pharmacology ; Echinomycin/*pharmacology ; Endothelin-2/genetics/*metabolism ; Female ; Gonadotropins, Equine/*pharmacology ; Granulosa Cells/drug effects/metabolism ; Humans ; Hypoxia-Inducible Factor 1, alpha Subunit/*antagonists & inhibitors/genetics/metabolism/physiology ; Oligonucleotides/genetics ; Ovary/cytology/drug effects/physiology ; Rats ; Rats, Sprague-Dawley ; Superovulation/*drug effects ; Transcriptional Activation

OBJECTIVETo investigate the regulation on endothelial function of sapindus saponins in spontaneously hypertensive rats by studying the reactivity on different vasoconstrictor and dilator, and the content of the active substances.

METHODForty 16-week-old spontaneously hypertensive rats were randomly divided into five groups, one with placebo as model group, one with captopril tablets (27 mg x kg(-1)) as positive control, one with low-dose sapindus saponins (27 mg x kg(-1)), one with medium-dose (54 mg x kg(-1)), one with high-dose (108 mg x kg(-1)). And another eight healthy Wistar-Kyoto strain (WKY) rats were used as the normal group. The animals were treated for eight weeks, and the indicators to be detected were as follows: (1) the response of thoracic aorta on different vasoconstrictors Ang II (1 x 10(-9) -1 x 10(-5) mol x L(-1)), PE (1 x 10(-8) 1 x 10(-4) mol x L(-1)), KCl (20 -120 mmol x L(-1)); (2) the endothelium-dependent or non-endothelium-dependent vasodilation response of thoracic aorta on Ach (1 x 10-(10)-1 x 10(-5) mol x L(-1)) or SNP (1 x 10(-8)-1 x 10(-3) mol x (L(-1); (3) the content of NO, 6-KPG1alpha, ET-1 and TXB2 in serum was determined by Elisa.

RESULTIn SHR model group, the response of thoracic aorta on Ang II, PE and KCl was increased, the endothelium-dependent vasodilation on Ach was reduced, but the effects on SNP was not obvious, the content of ET-1 and TXB2 was increased, and the content of NO and 6-KPG1alpha was reduced, Vs the normal control group, there were significant differences (P < 0.05 or P < 0.01); in the treatment groups, the response of thoracic aorta on Ang II, PE and KCl was reduced, the endothelium-dependent vasodilation of thoracic aorta on Ach was improved, the content of ET-1 and TXB2 was reduced, and the content of NO and 6-KPG1alpha was increased, Vs the SHR model group, there were significant differences (P < 0.05 or P < 0.01).

CONCLUSIONOur findings suggested that sapindus saponins protected the endothelial function in SHR, the mechanisms were relevant to the protection of endothelial function.

Angiotensin II ; pharmacology ; Animals ; Aorta, Thoracic ; drug effects ; physiology ; Endothelin-1 ; analysis ; Endothelium, Vascular ; drug effects ; physiology ; Female ; Male ; Nitric Oxide ; analysis ; Rats ; Rats, Inbred SHR ; Rats, Inbred WKY ; Sapindus ; chemistry ; Saponins ; pharmacology

OBJECTIVETo investigate the roles of hypoxia-inducible factor-1α (HIF-1α), endothelin-1 (ET-1) and inducible nitric oxide synthase (iNOS) in the pathogenesis of hypoxia-induced pulmonary hypertension (HPH) of the newborn.

METHODSSeventy-five term hospitalized neonates with HPH (mild 29 cases, moderate 25 cases, severe 21 cases) and 22 term hospitalized neonates without HPH (control group) were enrolled between June 2006 and November 2009. Serum levels of HIF-1α, iNOS and ET-1 were measured using ELASA 1, 3 and 7 days after birth.

RESULTSSerum concentrations of HIF-1α and ET-1 in the mild, moderate and severe HPH groups were significantly higher than those in the control group (P<0.01) 1 day after birth, and were related to the severity of HPH. The serum iNOS concentrations in the moderate and severe HPH groups were also significantly higher than those in the control group (P<0.01). By 3 days after birth, serum ET-1 concentration in the moderate HPH group and serum concentrations of HIF-1α, ET-1 and iNOS in the severe HPH group reminded significantly higher than those in the control group (P<0.05). At 7 days after birth, serum ET-1 concentration in the severe HPH group still remained higher than that in the control group (P<0.05).

CONCLUSIONSSerum levels of HIF-1α, ET-1 and iNOS increase in neonates with HPH, resulting in an imbalance of ET-1 and NO. This may be of importance in the pathogenesis of neonatal HPH.

Endothelin-1 ; blood ; physiology ; Female ; Humans ; Hypertension, Pulmonary ; etiology ; Hypoxia ; complications ; Hypoxia-Inducible Factor 1, alpha Subunit ; blood ; physiology ; Infant, Newborn ; Male ; Nitric Oxide Synthase Type II ; blood ; physiology

OBJECTIVETo observe the effect of Chinese herbal medicine for calming Gan (肝) and suppressing hyperactive yang (平肝潜阳, CGSHY) on arterial elasticity function and the circadian rhythm of blood pressure in patients with essential hypertension (EH).

METHODSAdopting a parallel, randomized design, sixty-four patients with EH of stages I and II were randomly divided into two groups according to a random number table, with 32 in each group. The patients in the treatment group were treated with CGSHY and those in the control group were treated with Enalapril. All patients were given 24-h ambulatory blood pressure monitoring (ABPM) before and after a 12-week treatment. Trough/peak (T/P) ratios of systolic and diastolic blood pressure (SBP & DBP) of each group were calculated. The circadian rhythm of their blood pressure was observed at the same time. The changes in elasticity of the carotid artery in the patients, including stiffness parameter (β), pressure-strain elastic modulus (Ep), arterial compliance (AC), augmentation index (AI), and pulse wave velocity (PVWβ) were determined by the echo-tracking technique before and after a 12-week treatment. In the meantime, their levels of nitric oxide (NO) and endothelin-1 (ET-1) were measured respectively.

RESULTSAfter treatment, all parameters in the 24-h ABPM and the elasticity of the carotid artery (β, Ep, AC and PVWβ) were markedly improved, the level of NO was increased, and ET-1 was decreased in both groups as compared with values before treatment (P<0.05 or P<0.01). Further, the improvements in the ratio of T/P of SBP & DBP and in the level of NO and ET-1 in the treatment group were more significant than those in the control group (P<0.05). There were no significant differences in all parameters in the ABPM monitoring and the elasticity of the carotid artery, the recovery of blood pressure circadian rhythm, and the therapeutic effect of antihypertension in EH patients between the two groups (P>0.05).

CONCLUSIONSChinese herbal medicine for CGSHY may lower the blood pressure smoothly and recover the circadian rhythm of blood pressure in EH patients. They may also improve the carotid elasticity of EH patients similar to that of Enalapril. The mechanism of action of Chinese herbs on EH might be related to the regulation of vascular endothelium function.

Antihypertensive Agents ; Arteries ; drug effects ; physiopathology ; Blood Pressure ; drug effects ; physiology ; Blood Pressure Monitoring, Ambulatory ; Circadian Rhythm ; drug effects ; physiology ; Drugs, Chinese Herbal ; therapeutic use ; Elasticity ; drug effects ; physiology ; Enalapril ; pharmacology ; therapeutic use ; Endothelin-1 ; metabolism ; Female ; Humans ; Hypertension ; drug therapy ; physiopathology ; Male ; Middle Aged ; Nitric Oxide ; metabolism ; Time Factors ; Treatment Outcome ; Yin-Yang

OBJECTIVETo study the changes and significance of serum hypoxia-inducible factor-1α (HIF-1α), endothelin-1 (ET-1) and calcium (Ca(2+)) levels in neonates with hypoxic pulmonary hypertension (HPH).

METHODSSeventy-five neonates with HPH (29 mild, 25 moderate and 21 severe) and 22 hospitalized neonates with non-HPH (control group) were enrolled. Pulmonary artery systolic blood pressure (PASP) was measured by bedside echocardiography within 24 hrs after birth. Serum levels of HIF-1α and ET-1 were measured using ELASA. Serum Ca2+ concentrations were measured with ion selective electrode.

RESULTSSerum levels of HIF-1α and ET-1 in the HPH group increased significantly compared with those in the control group (P<0.01), and were positively related with PASP (Rhif-1α=0.75, P<0.01; Ret-1=0.56,P<0.05). Serum Ca2+ levels in neonates with severe HPH were significantly lower than those in the control group (P<0.05). There were no correlation between serum Ca2+ levels and PASP.

CONCLUSIONSSerum HIF-1α and ET-1 levels are positively related with PASP in neonates with HPH, suggesting that serum HIF-1α and ET-1 may be involved in the occurrence of neonatal HPH. Serum Ca2+ levels are reduced in severe neonates with HPH, suggesting that serum Ca2+ may play a role in the occurrence of severe HPH.

Blood Pressure ; Calcium ; blood ; physiology ; Endothelin-1 ; blood ; Female ; Humans ; Hypertension, Pulmonary ; blood ; etiology ; Hypoxia ; complications ; Hypoxia-Inducible Factor 1, alpha Subunit ; blood ; Infant, Newborn ; Male ; Pulmonary Artery ; physiopathology

Endothelin (ET)-1 and its receptors (ETA and ETB receptor) are present in the central nervous system. ET exerts biological effects on gliogenesis and glial cell functions. In order to define a possible mechanism of ETA receptor signaling, the distribution of the ETA receptor in developing oligodendrocytes and the effects of ET-1 on the myelination of oligodendrocytes were examined. ETA receptor immunoreactivity was confined to the perivascular elements of the blood vessels during early postnatal development. However later in development, ETA receptor immunoreactivity was no longer observed in the vessels but became localized to the myelinating oligodendrocytes of the primitive corpus callosum of the white matter, apart from the vessels. ET-1 induced myelin basic protein (MBP) in primary oligodendrocyte precursor cell culture though the ETA receptor and was blocked by an ETA receptor antagonist. In addition, ET-1 evoked the release of Ca2+ which is a central regulator of oligodendrocyte differentiation. Our results provide a link between ET-1 and its ETA receptor and myelination during oligodendrocyte differentiation.
Animals ; Brain/pathology ; Calcium/metabolism ; Calcium Signaling ; Cells, Cultured ; Endothelin-1/metabolism/physiology ; Mice ; Mice, Inbred ICR ; Myelin Basic Proteins/genetics/metabolism ; Myelin Sheath/*physiology ; Oligodendroglia/cytology/*metabolism ; Rats ; Rats, Sprague-Dawley ; Receptor, Endothelin A/metabolism/*physiology

Lining the inner surface of the walls of blood vessels, Endothelial cells (ECs) go beyond providing selective membrane to maintain the natural structure and function of vessels; they also synthesize varieties of vasoactive proteins to modify the pressure shift in the local flow field and hence they adapt the physiological activities of vessels. In this experiment, ELISA and RT-PCR technologies were adopted. We set up five different pressure loaded ECs groups,one non-activated cultured ECs group and one single shear stress loaded ECs group. Such a design was intended to demonstrate the effects of pressure shift on the expression of vasoactive protein synthesized by ECs [Endothelin-1(ET-1), endothelial Nitric Oxide Synthase (eNOS), Cyclooxygenase-2(COX-2) and Vascular Endothelial Growth Factor(VEGF)]. Our aim was to elucidate the mechanism of the pressure shift mediated dysfunction in ECs and the related dose-effect relationship. Based on these data, we suggest that ECs could modify the expression of vasoactive protein for adapting to the pressure shift in the local flow field; while in the process of--40 cmH2O induced ECs' dysfunction, the vasoactive proteins eNOS, COX-2 and VEGF play an important role in protecting ECs.
Cells, Cultured ; Cyclooxygenase 2 ; genetics ; metabolism ; Endothelial Cells ; metabolism ; physiology ; Endothelin-1 ; genetics ; metabolism ; Humans ; Nitric Oxide Synthase Type III ; genetics ; metabolism ; Pressure ; RNA, Messenger ; genetics ; metabolism ; Vascular Endothelial Growth Factor A ; genetics ; metabolism