AIMThe purpose of the present study is to discuss the influence of different exercise load on the concentration of ET in plasma and myocardial cells, and the activity of ETR on myocardial cell's membrane in rats.

METHODS45 male SD rats were divided into the following 5 groups randomly: Group A (control group); Group B (45 min swim group); Group C (90 min swim group); Group D (150 min swim group); Group E (acute exhaust group). After having been trained for 8 weeks, the levels of ET and activity of ETR were measured by RIA.

RESULTSThe concentrations of ET in plasma and myocardial cells of 90 min swim group were decreased significantly (P < 0.01)and 90 min swim could reduce the activity of ETR (P < 0.01). The activity of ETR was elevated significantly in 150 min swim group (P < 0.01).

CONCLUSIONModerate exercise loads can significantly ameliorate the cardiovascular function, and high exercise loads is harmful to myocardial cells.

Animals ; Endothelin-1 ; metabolism ; Male ; Myocytes, Cardiac ; metabolism ; Physical Conditioning, Animal ; physiology ; Rats ; Rats, Sprague-Dawley ; Receptor, Endothelin A ; metabolism ; Swimming

To determine the relationship between the urinary endothelin (ET-1), nitric oxide (NO) levels and the clinical, pathologic types of primary glomerulonephritis (GN) patients, urinary levels of ET-1 and NO were detected in 27 patients with biopsy-proven primary GN and 12 normal controls by radioimmunoassay and by copper-plated and cadmium column reduction assay, respectively. The results showed that urinary ET-1 levels in the patients with primary GN were significantly higher than in normal controls (p < 0.01), while the urinary ET-1 levels in patients with moderate mesangial proliferation GN were significantly higher than those in patients with mild mesangial proliferation GN (p < 0.05). Urinary ET-1 levels in patients whose clinical feature was nephrotic syndrome were found to be higher than in patients whose clinical feature was nephritic syndrome. However, urinary NO levels were to the contrary (p < 0.05). The ratio of ET-1/NO in primary GN patients was significantly higher than that in normal controls, and it positively correlated with the 24-hour urinary excretion of protein. These results suggest that urinary ET-1 levels are related to the proliferation of mesangial cells. The imbalance between ET-1 and NO may be related to the pathogenesis of primary GN and the occurrence of proteinuria.
Adolescence ; Adult ; Endothelin-1/urine* ; Endothelin-1/physiology ; Female ; Glomerulonephritis/urine* ; Glomerulonephritis/etiology ; Human ; Male ; Middle Age ; Nitric Oxide/urine* ; Nitric Oxide/physiology ; Nitric-Oxide Synthase/metabolism

AIMTo investigate the effect of endogenous endothelin-1 (ET-1) on cardiomyocyte apoptosis induced by hypoxia and its possible mechanism.

METHODSCultured neonatal rat cardiomyocytes were divided into control group and ET receptor antagonist group. Control group was given DMEM only and ET receptor antagonist group was treated with ET receptor subtype A (ET(A)) receptor antagonist BQ610 and BQ123 or ET(B) receptor antagonist BQ788 and subjected to hypoxia for 24 h. The presence of apoptosis in cardiomyocytes was evaluated by TUNEL analysis and flow cytometry (FCM).

RESULTSTUNEL analysis showed that the percentage of positive apoptotic cells in BQ610 5 micromol/L group was 13.2% +/- 3.7%, significantly lower than that in hypoxia group (24.2% +/- 2.2%, P < 0.01). FCM showed that BQ123 (0.04, 0.2 and 1.0 micromol/L) inhibited hypoxia-induced cardiomyocyte apoptosis and increased cardiomyocyte survival rate in a dose-dependent manner, while BQ788 did not show such effects.

CONCLUSIONThese findings suggest that endogenous ET-1 aggravates hypoxia-induced cardiomyocyte apoptosis and this effect is mediated through ET(A) receptor-dependent pathways.

Animals ; Animals, Newborn ; Apoptosis ; Cell Hypoxia ; Cells, Cultured ; Endothelin A Receptor Antagonists ; Endothelin B Receptor Antagonists ; Endothelin-1 ; physiology ; Myocytes, Cardiac ; metabolism ; pathology ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo study the expression of ET receptor and the apoptosis after intervened with ET receptor antagonist in androgen-independent prostate cancer.

METHODSPC3, an androgen-independent prostate cancer cell line, was used. The expression of ETA and ETB receptor in PC3 was measured through RT-PCR. After intervened with selective ETA and ETB receptor antagonist, the apoptosis in PC3 was studied through flow cytometry and electron microscope.

RESULTSClear signal was obtained in PC3 for ETA receptor mRNA transcript, while the signal for ETB receptor mRNA transcript was very weak. The expression of ETA receptor mRNA was obviously reduced and the apoptosis of PC3 cell was observed after intervened with selective ETA receptor antagonist. There was no change after intervened with selective ETB receptor antagonist.

CONCLUSIONET-1 exerts its effects through the ETA receptor subtype and ETB receptor is silenced in PC3. The expression of ETA was reduced and the apoptosis was observed in PC3 when ETA receptor was blocked. It was dose-dependent.

Androgens ; physiology ; Apoptosis ; drug effects ; physiology ; Endothelin A Receptor Antagonists ; Endothelin B Receptor Antagonists ; Endothelin-1 ; physiology ; Humans ; In Vitro Techniques ; Male ; Neoplasms, Hormone-Dependent ; pathology ; Oligopeptides ; administration & dosage ; Peptides, Cyclic ; administration & dosage ; Piperidines ; administration & dosage ; Prostatic Neoplasms ; pathology ; physiopathology ; Receptor, Endothelin A ; metabolism ; physiology ; Receptor, Endothelin B ; metabolism ; physiology

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

Intercellular adhesion molecule-1 (ICAM-1) is an important adhesion molecule leading to adhesion between cells; NF-kappaB, being universally distributed in the organism, is an important nuclear transcription factor leading to a rapid response to the stimuli. Line of evidence have shown that ICAM-1 transcription and NF-kappaB activation is an important step of inflammatory reaction. To testify that intrapulmonary regulatory peptides modulate inflammatory lesion of bronchial epithelial cells (BECs) through their effect on ICAM-1 expression and nuclear factor kappaB (NF-kappaB) activation, we used immunocytochemistry, RT-PCR, and electrophoretic mobility-shift assay (EMSA) to determine the ICAM-1 expression and NF-kappaB activity in BECs. The effects of NF-kappaB inhibitor MG-132 on ICAM-1 expression were also observed. The results showed that vasoactive intestinal peptide (VIP) and epidermal growth factor (EGF) decreased ICAM-1 expression in O(3)-stressed BECs, while endothelin-1 (ET-1) and calcitonin gene-related peptides (CGRP) increased ICAM-1 expression in resting BECs. MG-132 blocked ICAM-1 expression induced by O(3), ET-1 and CGRP. The results obtained by using EMSA confirmed that VIP and EGF restrained the activation of NF-kappaB in O(3)-stressed BECs; CGRP and ET-1 promoted activation of NF-kappaB. These observations indicate that VIP and EGF abated the injury by means of down-regulatory effects on ICAM-1 transcription and NF-kappaB activation, while ET-1 and CGRP enhanced the inflammation reaction by an up-regulatory effect. It is suggested that a developing and intensive airway inflammation correlates closely with a persistent expression of ICAM-1 and repeated activation of NF-kappaB.
Animals ; Bronchi ; cytology ; Cell Adhesion ; physiology ; Cells, Cultured ; Endothelin-1 ; metabolism ; Epithelial Cells ; cytology ; metabolism ; Humans ; Inflammation ; metabolism ; Intercellular Adhesion Molecule-1 ; metabolism ; NF-kappa B ; metabolism ; Peptides ; physiology ; Rabbits ; Vasoactive Intestinal Peptide ; physiology

A few of flow experiments were utilized to verify a theoretical hypothesis proposed by Fung and coworker which showed that the tensile stress in the upper cell membrane of the vascular endothelium could accumulate upstream against the direction of blood flow. Endothelial cells from replicate human umbilical vein segment (HUVSEC) in vitro with length of 11 cm and 21 cm were exposed to the same pulsatile laminar shear stress averaged of 0.12 N/m2 for 42 hours. The average production rate of endothelin-1(ET-1), at 11 cm segment is 50% lower than that at 21 cm segment(16.93 +/- 0.89) vs. (26.13 +/- 1.79) pg/cm2.h respectively. The average production rate of ET-1 under pulsatile laminar flow was significantly higher than that under steady laminar flow. It showed that, high correlation of the length of HUVSEC with their ET-1 metabolism exists, suggesting that the tensile stress in the upper endothelial cell membrane could accumulate.
Cell Membrane ; physiology ; Endothelin-1 ; metabolism ; Endothelium, Vascular ; cytology ; physiology ; Humans ; In Vitro Techniques ; Infant, Newborn ; Stress, Mechanical ; Umbilical Veins ; anatomy & histology

OBJECTIVE: To determine the effect of pregnancy-associated plasma protein A (PAPP-A) on the function of vascular endothelial cells (VEC). METHODS: Human umbilical vein endothelial cell (HUVEC) line, derived from human umbilical vein, was cultured in vitro with PAPP-A at 0, 50, 100, and 200 ng/mL for 0, 12, 24, and 48 hours, respectively. Nitric oxide (NO) levels and endothlin-1 (ET-1) levels were determined by spectrophotometer and immunehistory. RESULTS: The NO levels of HUVECs in the PAPP-A groups were significantly lower than those in the control group (P<0.05). The ET-1 levels of HUVECs in the PAPP-A groups were significantly higher than those in the control group (P<0.05). The changes were all dose-dependent. CONCLUSION PAPP-A may affect the function of vascular endothelial cells by reducing the secretion of NO and increasing the level of ET-1.
Cell Line ; Endothelial Cells ; cytology ; metabolism ; physiology ; Endothelin-1 ; biosynthesis ; Female ; Humans ; Nitric Oxide ; biosynthesis ; Pregnancy-Associated Plasma Protein-A ; pharmacology ; Umbilical Veins ; cytology ; metabolism

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

The effects of endothelin-1 (ET-1) and other drugs on the reactive oxygen species (ROS) generation and cardiomyocyte hypertrophy were examined in experiments on the cultured neonatal rat cardiomyocytes. The role of ROS on neonatal rat cardiomyocyte hypertrophy induced by ET-1 was studied and the relationship of PKC activation and ROS generation was investigated. The level of intracellular ROS was measured by the ROS-specific probe 2',7'-dichlorofluorescin diacetate (DCF-DA). Cardiomyocyte hypertrophy was determined by the RNA content, the total protein of cells and the cell surface area. The results are as follows. The fluorescence intensity of intracellular DCF-DA increased by 77% in cultured neonatal rat cardiac myocytes treated with ET-1 (10 nmol/L) vs control group. Compared with control group, the fluorescence intensity of intracellular PI, protein content and cell surface area increased by 128%, 87% and 151% respectively (all P<0.01) in cardiac myocytes treated with ET-1 (10 nmol/L). ABT-627, CC, or CAT inhibited the ET-1-induced increase in fluorescence intensity of intracellular DCF-DA by 62%,60% and 51% respectively (all P<0.01), and also attenuated the cardiac hypertrophy. The fluorescence intensity of intracellular DCF-DA increased by 74% (P<0.01) in myocytes treated with PMA (1 micromol/L) vs control group. Therefore, in the course of cardiomyocyte hypertrophy, ET-1 increases intracellular ROS in the cultured neonatal rat cardiac myocytes and inhibits cardiomyocyte hypertrophy induced by ROS. The ET(A) and PKC activation mediate the ROS production and cardiomyocyte hypertrophy induced by ET-1. ROS is necessary in the ET-1-induced cardiomyocyte hypertrophy.
Animals ; Animals, Newborn ; Cell Enlargement ; Cells, Cultured ; Endothelin-1 ; physiology ; Female ; Hypertrophy ; Male ; Myocytes, Cardiac ; cytology ; pathology ; Rats ; Rats, Sprague-Dawley ; Reactive Oxygen Species ; metabolism