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Objective: To investigate the effects of the epidermal growth factor on the mRNA expression of endothelin-1 and its receptors (ET(A)R, ET(B)R) in hormone refractory prostate cancer (HRPC) PC-3 cell lines., Methods: PC-3 cells were cultured in vitro. After the treatment with EGF, the mRNA expressions of endothelin-1, ET(A)R and ET(B)R were detected by RT-PCR in PC-3 cell lines. The levels of the mRNA expression of endothelin-1 and its receptors were examined at different time points by RT-PCR., Results: The expressions of endothelin-1 and ET(A)R mRNA but not the mRNA expression of ET(B)R was observed in PC-3 cell lines. After 24 hours of treatment with EGF, the expressions of endothelin-1 and ET(A)R in PC-3 cell lines were both up-regulated and there was significant difference (P < 0.05) between the experimental and control groups. Different expression levels of endothelin-1 and ET(A)R mRNA were noted at different time points of EGF intervention, up-regulated with the increase of treatment time, and with significant difference (P < 0.05)., Conclusion: EGF can up-regulate the mRNA expressions of endothelin-1 and ET(A)R in PC-3 cell lines and play a great role in prostate cancer progression, which may offer a substructure of molecular biology for the treatment of HRPC.

Objective: To investigate the effect of endothelin and its receptors on ouabain-induced hypertension in rats., Methods: Male Sprague-Dawley (SD) rats were treated with ouabain or saline for 6 weeks and their systolic blood pressure (SBP) were recorded weekly. At the end of 2, 4 and 6 weeks, respectively, the plasma and left ventricle endothelin contents were measured by radio-immunoassay, and real-time quantitative RT-PCR was employed to determine the mRNA level of endothelin type A receptor (ETAR) and type B receptor (ETBR) in the left ventricle, and the protein expressions of ETAR and ETBR were examined by immuno-histochemistry., Results: After 4 weeks of intraperitoneal ouabain injection, the mean SBP in ouabain group increased till reaching a level significantly higher than that in the control group after 6 weeks (P<0.001). The plasma and left ventricle endothelin contents were significantly increased after 2 weeks of ouabain injection (P<0.01), and similarly, increased ETAR mRNA was observed. After 4 weeks of treatment, ETAR mRNA was increased continuously and the protein expression of ETAR upregulated in ouabain group as compared with the control group. The transcription and protein expression of ETBR were not altered by ouabain treatment., Conclusion: Before detectable blood pressure elevation occurs, endothelin concentration and ETAR can be already upregulated in ouabain-induced hypertensive rats, suggesting that endothelin might be involved in the cardiovascular effects of ouabain via an action on ETAR.

Objective: To explore the therapeutic effects and mechanisms of the combination of traditional Chinese medicine and western medicine on patients with peptic ulcers., Methods: One hundred and twenty patients were randomly divided into 6 groups. Another 10 patients as the control group were confirmed with no peptic ulcers by endoscope, but had digestive tract symptoms. The clinical effects were compared among each group after the one month treatment., Results: The clinical effects of the combination of Jianweiyuyang granules and ranitidine capsules were better than those of western medicine, with improvement in symptoms and syndrome (P < 0.01 to 0.05), but there was not significant difference with the rate of ulcer healing and the Hp clearance among the combination of Jianweiyuyang granules and ranitidine capsules, Jianweiyuyang granules, and ranitidine capsules (P > 0.05). The combination of Jianweiyuyang granules and ranitidine capsules could significantly upregulate the expression of MUCSAC mRNA (P < 0.01), while downregulate the expression of ETAR mRNA (P < 0.01)., Conclusion: There is obvious advantage in treating peptic ulcers by the combination of Jianweiyuyang granules and ranitidine capsules, and its mechanisms may be to protect the gastric mucosal barrier by up-regulating the expression of MUCSAC mRNA and to improve the gastric mucosal blood flow by down-regulating the expression of ETAR mRNA.

In the present study, the effects of 17 beta-estradiol on vascular reactivity of ovariectomized rats and proliferation of cultured rat aortic smooth muscle cells were studied. The vascular reactivity was significantly increased in ovariectomized rats compared with the sham-operated animals. The selective ETA receptor antagonist BQ123 inhibited the increase in [3H]-TdR incorporation in response to ET-1 on vascular smooth muscle cells (VSMCs). 17 beta-estradiol also attenuated the ET-1 effects in a dose-dependent manner. The results of RT-PCR and Western blot show that expression of ETA receptor was decreased after treatment with 17 beta-estradiol. The effect of 17 beta-estradiol was partially inhibited by estrogen receptor antagonist tamoxifen. The above results demonstrate that proliferation of VSMCs stimulated by ET-1 was mainly mediated through ETA receptor. Due to the down-regulation of ETA receptor and mediation of estrogen receptor, 17 beta-estradiol inhibits the ET-1-induced proliferation of VSMCs and decreases the vascular reactivity of ovariectomized rats.

Endothelin(ET) is the most potent mammalian vasoconstrictor identified to data. As a pathogenic factor, ET is involved in the genesis of many diseases. In this study, a pair of primers was designed and synthesized according to the human ETB receptor gene (hETBR) sequence. A 394 bp of DNA fragment was amplified by polymerase chain reaction(PCR) and labeled with alpha-32P-CTP using Random Primer-Labeling method. With this probe, rabbit lung cDNA library was screened by in situ hybridization and 11 positive clones were identified. Sequencing result showed that a complete reading frame of rabbit ETB receptor(rETBR) cDNA could be produced from three positive clones of eleven. By a series of subcloning, a recombinant plasmid including the 1326 bp of rETBR coding sequences, named pBlu Script-rETBR, was constructed. The deduced amino acid sequence indicated that the rETBR is 441 residues in length, with an expected molecular mass of approximately 49.44 kD. N-terminal 18 residues is the potential signal peptide (Score = 11.11) and therefore the molecular mass of mature rETBR is 47.65 kD with 423 amino acid residues. Analysis of the rETBR hydropathy profile indicates the presence of seven hydrophobic regions, putative transmembrane domains. Potential N-glycosylation sites are the 60th and the 118th. The structure exhibits a significant sequence and topographical similarity with G protein-coupled receptors.

Objective: To study the expression of endothelin 1 (ET-1) and tumor necrosis factor (TNFalpha) in the epithelial cells of normal and injured renal tubules and their influences on renal interstitial fibroblasts., Methods: Cultivation of renal tubular epithelial cells and renal interstitial fibroblasts and establishment of a renal tubulo-interstitial fibrosis (TIF) animal model; reverse transcription-polymerase chain reaction (RT-PCR), immunohistochemical staining, radioimmunoassay (RIA), double immunohistochemical; and (3)H-TDR incorporation techniques were applied to study the relationship between ET-1, plus TNFalpha and the proliferation of renal interstitial fibroblasts., Results: Expression of ET-1 mRNA and TNFalpha mRNA from renal tubular epithelial cells was obtained (546 bp and 415 bp) respectively as well as the relevant ET-1 and TNFalpha proteins. The concentration of ET-1 and TNFalpha in the culture medium were 1.42 pg/ml and 0.58 ng/ml respectively. The amount of ET-1 and TNFalpha was increased during cell injury and regeneration. In addition, the ratio of (3)H-TDR incorporation and the expression of ET-R mRNA and TNF-R1 mRNA (545 bp and 347 bp) were markedly increased than that of the control group (P < 0.05) when ET-1 or TNFalpha was added in the culture media., Conclusion: Injured and regenerated renal tubular epithelial cells are able to synthesize and liberate more ET-1 and TNFalpha than that of the normal renal tubules. ET-1 and TNFalpha are also effective in promoting the proliferation of renal interstitial fibroblasts through ET-R and TNF-R.

Objective: To determine the distribution of endothelin (ET) peptide and endothelin as well as their receptors (ETaR and ETbR) mRNA in human cycling endometrium in order to assess possible role of ET in endometrial reproductive physiology., Methods: Twenty-three endometrial specimens from gynecological surgery for benign conditions were studied by means of immunohistochemistry, in situ hybridization and computer quantitative image analysis., Results: The expression of ET peptide and ET mRNA in human endometrium varies throughout the menstrual cycle, increasing gradually from proliferative phase to secretory phase, with maximal levels in the pre-menstrual phase. Stromal expression is lower than in glandular epithelium and remains relatively constant in the menstrual cycle. ETaR and ETbR mRNA are detected in normal human endometrium, higher in glandular epithelial cells than in stromal cells. ETaR mRNA expression has no obvious cyclic changes, but ETbR mRNA expressions are higher in secretory endometrium than in proliferative endometrium. The ratio of ETaR/ETbR has also cyclic changes., Conclusion: Changes of Expression of ET and ET receptors in the endometrium throughout the menstrual cycle suggest that ET might be important in endometrial regeneration and repair following menstruation, and probably plays a role as the paracrine control of the uterine vascular bed.

Objective and Methods: We studied expression of messenger RNAS for endothelin-1 (ET-1) and its receptor subunits (ETA, ETB) by northern blot hybridization and in situ hybridization in rat kidney following 30% TBSA full thickness burns., Results: Expressions of that ET-1, ETA, and ETB mRNA expression are all evidently increased at 1 hour postburn. ET-1 and ETA reached its maximal mRNA expression at 3 hour postburn. ET-1 mRNA distributed primarily on glomerular endothelial cells and tubular epithelial cells in cortex. ETA mRNA predominantly presented on smooth muscle cells of small arterioles in renal cortex. However, the peak time of ETB mRNA expression is at 6 hour postburn and mainly localized on renal medullary tubular epithelial and collecting duct cells., Conclusion: These findings suggest that 1. ET-1 acts principally as a local paracrine/autocrine peptide. 2. Increased ET-1 that activated ETA receptors accentuated expression on vascular smooth muscle cells will result in renal cortex ischemia. 3. Accentuated expression of ETB receptor on tubular epithelial cells may induce renal natriuretic action and reduction of water execretion. 4. Increased ET-1 and its receptors in kidney play an important role in the pathogenesis and development of renal function impairment following severe burn.

The interrelationship between endothelin (ET), endothelin receptors (ET-R) and glomerular mesangial cells (MC) was investigated by MC culture, RT-PCR, Northern blot hybridization, DNA cytometry and immunohistochemistry methods. The results showed that in MC, there existed the expression of ET mRNA and also the expression of 2 subsets ETA mRNA and ETB mRNA. ET mRNA peptide is synthesized in MC. ET mRNA induced significant MC contraction and stimulated MC division and proliferation. The results suggest that MC are special cells with the capacity of producing ET and are also the target cells for ET. It is possible that ET influence glomerular filtration area and rate by inducing MC contraction and cause also MC proliferation and glomerular sclerosis.

Endothelins (ETs) are a family of novel regulatory peptides which can constrict the vascular and promote the proliferation of vascular smooth muscle cells. Serum ET-1 was elevated, and nitric oxide (NO) levels were reduced in hypoxic pulmonary hypertension. However, the exact mechanism remains unclear, and no study has elucidated if hypoxia could stimulate directly overgrowth of right ventricle in patients with chronic cor pulmonale. To investigate the role of ET-1 and NO in hypoxia-induced pulmonary hypertension and right ventricular hypertrophy, we measured the levels of ET-1 mRNA, ET receptor-A (ETR-A) mRNA and nitric oxide synthase (NOS) mRNA in the pulmonary artery and right ventricle of rats exposed to hypoxia (FiO = 0.1, 8 hours daily for 1, 2 and 3 weeks) by reverse transcription-polymerase chain reaction (RT-PCR). ET-1 mRNA level of pulmonary artery raised after 1 week's hypoxia (P < 0.05), and after 2 weeks' hypoxia, it returned to near normal, but elevated significantly again after 3 weeks' hypoxia. Pulmonary artery ETR-A mRNA in 1 and 2 weeks hypoxic groups showed no significant change, but it raised significantly in 3 weeks' hypoxic group. After exposure to hypoxia for 1, 2 and 3 weeks, NOS mRNA in the pulmonary artery all reduced significantly (P < 0.05). The right ventriculus cordis showed a significant increase in weight after 3 and 2 weeks' hypoxia. ET-1 mRNA showed no significant change but ETR-A mRNA increased significantly after 2 weeks' hypoxia; both ET-1 mRNA and ETR-A mRNA showed significant increase in weight after 3 and 2 weeks' hypoxia. In the ventriculus cordis of rats exposed to hypoxia for 2 and 3 weeks, NOS mRNA had no significant change.