The correlation between pulmonary endothelin receptors and alveolar-arterial oxygen gradient (A-aDO2) in rats with hepatopulmonary syndrome was investigated. Animals were divided into 2 groups: Sham-operated (Sham) group and common bile duct ligation (CBDL) group. Arterial blood gas was evaluated by a blood gas analyzer. The concentrations of ET-1 in blood and lung tissue sample were evaluated by radioimmunoassay. The distribution and expression of two kinds of subtype receptor of ET-1, ETRA and ETRB were examined by in situ hybridization. The results showed that the level of A-aDO2 was higher in CBDL group than that in Sham group (P < 0.05). The levels of plasma and pulmonary ET-1 in CBDL group were both higher than in Sham group (P < 0.05). There was no significant difference in average A of ETRA between two groups by imaging analysis (0.21 +/- 0.06 vs 0.22 +/- 0.08, P > 0.05), while that of ETRB was higher in CBDL group than in Sham group (0.58 +/- 0.16 vs 0.28 +/- 0.07, P < 0.05). The expression of ETRB in lung was positively correlated with A-aDO2 (P < 0.05). It was concluded that the widened A-aDO2 may be related with enhancement of the expression of ETRB in lung.
Endothelin-1/metabolism ; Hepatopulmonary Syndrome/*metabolism ; Lung/*metabolism ; Oxygen/*metabolism ; Pulmonary Alveoli/*metabolism ; Rats, Wistar ; Receptor, Endothelin A/metabolism ; Receptor, Endothelin B/*metabolism

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

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

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 role of endothelin-1 in the pathogenesis of neurogenetic pulmonary edema.

METHODSThe levels of endothelin-1 in plasma and lung were measured in rats which suffered from diffuse brain injury on Marmarous' model. The changes of endothelin-1 in the lungs were also detected using an immunohistochemical method.

RESULTSAfter heavy diffuse brain injury in rats, the levels of endothelin-1 in plasma and lung began increasing at 1 hour, and peaked at 6 hour. Though a little declining at 24 hour, it maintained a higher level within 48 hours (P < 0.05). Pulmonary pathology showed that after brain injury there were congestion, swelling in pulmonary microvessels with broadened pulmonary interstitial tissue, and leucocyte infiltration was dominated by neutrophils and monocytes from 1 hour on, which peaked at 6 hour. More serious congestion, swelling and protein effusion in pulmonary alveoli were observed at both 24 h and 48 h. Immunohistochemically, endothelin-1 had more significant expression and higher levels of OD in the experimental groups than that in the control's, the most significance of which was at 6 hour.

CONCLUSIONThe inflammatory injury mechanism caused by endothelin-1 may play an important role in neurogenic pulmonary edema.

Animals ; Endothelin-1 ; metabolism ; Lung ; metabolism ; Male ; Pulmonary Alveoli ; metabolism ; Pulmonary Edema ; etiology ; metabolism ; Rats ; Rats, Wistar

OBJECTIVETo explore whether endothelin-1 and NO are involved in the instant changes in cardiac function at early stage of severe burn.

METHODS(1) Thirty-one Wistar rats were divided into sham burn A group (SA, n = 7), burn A group (BA, n = 10), non-selective endothelin A/B receptor antagonist PD142893 group (n = 7), and the selective endothelin A receptor antagonist BQ-123 group (n = 7) according to the random number table. Rats in the latter three groups were inflicted with 30% TBSA full-thickness burn. Immediately after injury, rats in PD142893 group and BQ-123 group were intravenously injected with PD142893 (0.1 mg/kg) and BQ-123 (30 nmol x kg(-1) x min(-1)) respectively. Rats in SA group were treated the same as rats in BA group except for sham injury. The cardiac function indexes of rats in BA and SA groups including left ventricular systolic pressure (LVSP) heart rate (HR) and LV + or - dp/dt max were monitored before injury and 10, 30, 60, 180 minutes post injury (PIM) using physiological signal acquisition and processing system. The respective changes in cardiac function indexes of rate in each group between PIM 10 and pre-injury in the value of percentage were calculated. (2) Another 20 Wistar rats were enrolled and divided into sham burn B group (SB, n = 4) and burn B group (BB, n = 16) according to the random number table, and they were subjected to above-mentioned injury. Heart tissues of rats in BB group were obtained at PIM 10, 30, 60, and 180 respectively (4 rats at each time point), and that in SB group were obtained immediately after injury. Endothelin-1 and NO contents in heart tissues were determined with ELISA.

RESULTS(1) Compared with the pre-injury value, LVSP, HR, LV +dp/dt max, LV -dp/dt max of rats in BA group decreased significantly since PIM 10 (with F value respectively 7.14, 16.40, 14.09 14.98, P < 0.05 or P < 0.01). No significant change was observed in above 4 indexes in rats of SB group between above mentioned two time points (with F value respectively 0.59, 0.51, 1.03, 1.04, P values all above 0.05). (2) In BA group, compared with the pre-injury value, LVSP decreased 27%, HR decreased 14%, LV +dp/dt max decreased 51%, LV -dp/dt max decreased 50% at PIM 10. Compared with those in BA group at PIM 10, cardiac function indexes were improved significantly in PD142893 group, with LVSP decreased 14% (F = 8.10, P < 0.01), HR increased 4% (F = 6.50, P < 0.01), LV +dp/dt max decreased 31% (F = 23.67, P < 0.05), LV -dp/dt max decreased 14% (F = 10.39, P < 0.01). In BQ-123 group, compared with the pre-injury value, HR increased 3%, LV -dp/dt max decreased 26% at PIM 10, which were obviously improved as compared with those in BA group (with F value respectively 6.50 and 10.39, P < 0.05 or P < 0.01); the percentage changes of LVSP and LV +dp/dt max in BQ-123 group were close to that in BA group (with F value respectively 8.10 and 23.67, P values both above 0.05). (3) Compared with those in SB group, myocardial tissue endothelin-1 content of rats in BB group increased significantly at PIM 10, 60, 180 (F = 2.85, P < 00.05 or P < 0.01), and NO content increased significantly at PIM 60, 180 (F = 1.87, with P values all below 0.05).

CONCLUSIONSEndothelin-1 may participate in the instant decline of cardiac function of rats at early stage of severe burn, and plays an important role in the instant myocardial damage after injury.

Animals ; Burns ; metabolism ; physiopathology ; Endothelin-1 ; metabolism ; Heart ; physiopathology ; Male ; Myocardium ; metabolism ; Nitric Oxide ; metabolism ; Rats ; Rats, Wistar

OBJECTIVETo observe the effect of electroacupuncture (EA) stimulation on the expressions of angiotensinogen (AGT), angiotensin II type 1 receptor (AT1R), endothelin-1 (ET1), and endothelin A receptor (ETAR) mRNA in spontaneously hypertensive rat (SHR) aorta.

METHODSEighteen male SHRs were randomly divided into three groups, an SHR group, an SHR Baihui (DU 20) and Zusanli (ST 36) acupoint (SHR-AP) group, and an SHR non-acupoint (SHR-NAP) group, with 6 rats in each group. Six Wistar rats were used as a control. Rats in the SHR-AP group were stimulated by DU 20 and ST 36 acupoints, both of which were connected with EA. EA was handled one time every Monday, Wednesday and Friday, for total 24 times (8 weeks). SHRNAP rats were acupointed at a 15°angle flat into 0.5 cm to two points, which were 1 and 2 cm from rail tip separately. EA parameters were the same as the SHR-AP rats. SHR control rats and Wistar rats were fixed without EA. Real-time quantitative polymerase chain reaction (PCR) was used to measure AGT, AT1R, ET1, and ETAR mRNA expression in rat aorta.

RESULTSEA stimulation significantly reduced rat aorta vascular AGT, ET1, ETAR and AT1R mRNA expressions in the SHR-AP and SHR-NAP groups (P <0.01). Among these four genes, AT1R mRNA expression was significantly lower in the SHR-AP than in the SHR-NAP group (P <0.01).

CONCLUSIONEA could reduce the AT1R mRNA expression in SHR-AP rat aorta, indicating a potential mechanism for the hypotensive effects of EA.

Angiotensinogen ; genetics ; metabolism ; Animals ; Aorta ; metabolism ; physiopathology ; Blood Pressure ; Electroacupuncture ; Endothelin-1 ; genetics ; metabolism ; Gene Expression Regulation ; Male ; RNA, Messenger ; genetics ; metabolism ; Rats, Inbred SHR ; Receptor, Angiotensin, Type 1 ; genetics ; metabolism ; Receptor, Endothelin A ; genetics ; metabolism

Expression of endogenous ouabain in placenta and the concentrations of serum ET-1 and NO were examined in 30 patients with hypertensive disorder complicating pregnancy (HDCP) and 30 healthy pregnant women to investigate the effect of endogenous ouabain on HDCP. Compared with the healthy pregnant group, the expression of endogenous ouabain dramatically increased in the HDCP groups (P<0.01). There was a significantly positive correlation between the expression of endogenous ouabain with ET-1 (r=0.5567, P<0.01), while the correlation of endogenous ouabain and NO was significantly negative (r=-0.6895, P<0.01). As expected, the correlation between ET-1 and NO was negative (r=-0.7796, P<0.01). ET-1 concentrations of maternal and cord sera in HDCP groups were significantly higher in comparison with healthy pregnant group (P<0.01). On the contrast, NO concentrations were much lower in the maternal and cord sera of HDCP groups as compared with healthy pregnant group (P<0.01). Our data suggest that endogenous ouabain is directly involved in the nosogenesis of HDCP, with accompanying decreased NO and the elevated of ET-1.
Case-Control Studies ; Endothelin-1/*blood ; Hypertension, Pregnancy-Induced/*metabolism ; Nitric Oxide/*blood ; Ouabain/*metabolism ; Placenta/*metabolism

Endothelin derived from the endothelial cells of microvessel is a potent vasoactive peptide, which has various physiologic actions in many internal organs. The fact that endothelin receptors are present on the osteoblastic cells suggests that endothelin play a role in bone metabolism. This study was done to study the effect of endothelin-1 on osteoblast and the combined effect of dexamethasone and endothelin-1 on osteoblast. Human osteoblasts isolated from ilium were cultured in DME/F12 medium, and divided into 5 groups; Group 1 (control), Group 2(10(-7)M endothelin-1), Group 3(10(-7)M endothelin-1+1:2500 monoclonal antibody), Group 4(10(-7)M dexamethasone+10(-7)M endothelin-1), and Group 5(10(-7)M dexamethasone). [3H]-thymidine uptake in groups was 23373.2+/-2722.4 cpm/well, significantly higher than that of control (P<0.05), and the increase was blocked by the addition of monoclonal antibody to endothelin(group 3). [3H]-thymidine uptake in groups adding steroid with or without endothelin was significantly lower than that of other groups (P<0.05). Group 2 showed marked increase in type I procollagen mRNA compared with other groups, but group 3 and 4 showed no significant effect on the expression of type I procollagen mRNA. In histochemical staining for alkaline phosphatase activity, the cells in groups with steroid were strongly positive in staining, large in size and looked well differentiated. Osteocalcin synthesis was also increased in groups with steroid treatment compared with other groups. This study demonstrated that endothelin-1 stimulated DNA synthesis and the expression of type I procollagen mRNA in human osteoblasts, and inhibited alkaline phosphatase activity, but had no significant effect on osteocalcin. Dexamethasone stimulated alkaline phosphatase activity and osteocalcin synthesis, and inhibited DNA synthesis but had no significant effect on the expression of type I procollagen mRNA. Dexamethasone masked the effect of endothelin-1 on human osteoblastic cells, and the effect of dexamethasone was predominant in the group of a combination of endothelin-1 and dexamethasone.
Alkaline Phosphatase ; Collagen Type I ; Dexamethasone ; DNA ; Endothelial Cells ; Endothelin-1 ; Endothelins* ; Humans ; Ilium ; Masks ; Metabolism ; Microvessels ; Osteoblasts* ; Osteocalcin ; Receptors, Endothelin ; RNA, Messenger

OBJECTIVETo study the targeted point and mechanism of the function of the blood-activating and stasis-removing Chinese drugs, Paeoniae Radix 801(PR801) in its cardiovascular protective effects and its specific binding with endothelin 1 (ET-1) as well as the dynamics of the two's interactive function by means of using affinity biosensors: IAsys Plus and quartz crystal microbalance (IAQCM).

METHODSET-1 was immobilized on the surfaces of IAQCM by using the new surface modification methods. The PR801 in the solution was detected by modified substrates and the specific binding between PR801 and ET-1 was studied.

RESULTSThe curves went up or down after adding PR801. There is specific binding between PR801 and ET-1. The bound mass were 0.458 ng/mm(2) and 133.54 ng/cm(2), respectively. There exists relatively good stability with these two methods.

CONCLUSIONThe affinity biosensors: IAQCM can be used to study the interaction mechanism between PR801 and ET-1, providing a new way to study the interaction mechanism of TCM. PR801 can bind ET-1 specifically in the experiments. Therefore, ET-1 is another target that PR801 can bind specifically besides thromboxane A(2).

Biosensing Techniques ; standards ; Blood Circulation ; drug effects ; Drugs, Chinese Herbal ; metabolism ; therapeutic use ; Endothelin-1 ; metabolism ; Humans ; Quartz