In the freshly isolated rat nephron, the effect of endothelin-1, -2 and -3 (ET-1, -2 and -3) on cytosolic free calcium concentration ((Ca2+)i) was determined using the fluorescent indicator Fura-2/AM. (Ca2+)i increase was investigated in 9 parts of the single nephron including glomerulus (Glm), S1, S2, S3, Cortical and medullary thick ascending limb and cortical (CCT) and outer medullary collecting tubule (OMCT). Endothelins increased (Ca2+)i in Glm (ET-1; 127+/-17%, ET-2; 93+/-5%, ET-3; 169+/-17%), CCT (ET-1; 30+/-6%, ET-2; 38+/- 19%, ET-3; 158+/-18%) and OMCT (ET-1; 197+/- 11%, ET-2; 195+/- 11%, ET-3; 215+ 37%) at 10(-7) M. In OMCT, ET-1 and ET-2 increased (Ca2+)i in a dose-dependent manner (10(-10) ~ 10(-6) M). To the contrary, ET-3-induced (Ca2+)i rise was begun from 10(-12) M. BQ-123Na, an antagonist of ETA receptor, at 10(-4) M inhibited about 30% of (Ca2+)i rise induced by ET-1 and -3. Binding experiments using (125I)ET-3 showed the existence of ETB receptor in OMCT. This binding was replaced by ET-1, ET-2 or ET-3 by the almost same degree but not by angiotensin II or vasopressin.
Angiotensin II ; Animals ; Calcium* ; Cytosol ; Endothelin-1 ; Endothelin-2 ; Endothelins* ; Extremities ; Nephrons* ; Rats* ; Vasopressins

BACKGROUND: Recent studies have documented increased release of endothelin(ET) during acute attack of asthma. The purpose of this study is to observe the link between plasma level and urinary excretion of each and changes during acute exacerbation. METHOD: Plasma and 24 hour urine were collected from sixteen asthmatics during acute exacerbation, twice ; first day of symptomatic exacerbation and two weeks after treatment. Controls were ten healthy normal subjects. All patients were treated with corticosteroid and beta-2 adrenergic agonist on admission. ET was determined by radioimmmunoassay and had 100% cross reactivity with ET-1, 67% with ET-2, 84% with ET-3, and 8% with Big-ET. RESULTS: Plasma ETs were significantly elevated during acute attack of asthma compared with those in remission and controls. However, there was no significant changes in urine ET concentrations or total ET amounts in 24 hour urine during exacerbation upto two weeks. Those levels of urine ET in asthmatics were still higher than controls. ET concentrations in plasma or urine were not correlated with pulmonary functional parameters and hypoxemia. CONCLUSION: The findings suggests that increased plasma ETs are related with exaggerated release during acute asthma. Urinary ET excretion is increased in asthma. However, urine ET changes during exacerbation should be observed in a larger and longer scale.
Adrenergic Agonists ; Anoxia ; Asthma* ; Endothelin-2 ; Endothelins* ; Humans ; Plasma*

BACKGROUND: Monocyte chemoattractant protein- 1 (MCP-1) is an important mediator for monocyte/ macrophage infiltration in various inflammatory renal diseases and is produced by renal cells. In the process of renal diseases, endothelin-1 (ET-1) is known to play an active role in cell growth, inflammation and fibrosis. The aim of this study was to investigate whether three isoforms of endothelin regulate MCP-1 expression in cultured mesangial cells. METHODS: Mesangial cells were incubated with or without various doses of ET-1, ET-2 or ET-3. To determine the monocyte chemotactic activity, chemotaxis assay was performed in modified Boyden chambers using freshly isolated human monocytes. MCP-1 mRNA expression in mesangial cells was measured by Northern blot analysis. RESULTS: ET-1, ET-2 and ET-3 stimulated monocyte chemotactic activity released from mesangial cells in a dose-dependent manner. ET-1, ET-2 and ET-3 also stimulated MCP-1 mRNA expression in a time-dependent manner, which was seen as early as 4 hours and was maintained up to 24 hours. CONCLUSION: These data suggest that ET-1, ET- 2 and ET-3 stimulate MCP-1 expression in mesangial cells and may contribute to the monocyte/ macrophage infiltration in inflammatory renal diseases.
Animals ; Blotting, Northern ; Chemokine CCL2* ; Chemotaxis ; Endothelin-1* ; Endothelin-2* ; Endothelin-3* ; Endothelins ; Fibrosis ; Humans ; Inflammation ; Macrophages ; Mesangial Cells* ; Monocytes* ; Protein Isoforms ; Rats* ; RNA, Messenger

OBJECTIVE: To investigate the roles of ET in the regulation of peripheral vascular tone, we studied the effect of hyperlipidemia on vascular responsiveness in femoral arteries from rabbits with control groups of rabbits and test groups receiving a hyperlipidemic diet. MATERIALS AND METHODS: New Zealand Whites were anesthetized with pentobabital and killed by exsanguination from the femoral arteries. Arteries which were suspended on muscle chambers at their optimal length for contractile properties, were examined. RESULTS: 1. After 14-16 weeks of cholesterol-rich diet, plasma cholestrol and HDL levels were significantly higher in the hyperlipidemic rabbits than in the control rabbits. There was no significant difference in the triglyceride levels between the two groups. 2. The contractions caused by 60 mM KCI in the femoral arterial strips were significantly augmented (P<0.01). The contractile responses to phenylephrine or angiotensin II were also augmented, whereas 5-hydroxytryptamine or U46619- induced contraction was not affected by the hyperlipidemic diet. 3. In control rabbits, ET-1 and ET- 2 contracted femoral arteries in a concentraction-dependent manner, whereas sarafotoxin S6c and IRL 1620 had no effect. 4. Contractions caused by ET-1 and ET-2 were significantly diminished by hyperlipidemia. 5. ET-1-induced concentration-response curves were inhibited by BQ-610, but not affected by BQ-788 in the femoral arterial strips from control and hyperlipidemic rabbits. CONCLUSIONS: These results suggest that ET is involved in the regulation of vascular tone in peripheral arteries and ETA receptor subtypes are mainly present in rabbit femoral arteries. Further more, ET-induced contraction is attenuated in hyperlipidemic rabbit, and the attenuated responses might be caused at least in part by the alteration of ET receptors (e.g. desensitization).
Angiotensin II ; Arteries ; Diet ; Endothelin-2 ; Endothelins* ; Exsanguination ; Femoral Artery* ; Hyperlipidemias ; New Zealand ; Phenylephrine ; Plasma ; Rabbits* ; Receptors, Endothelin ; Serotonin ; Triglycerides

OBJECTIVE: We examined the vasoconstricting poperties of endothelin (ET) on isolated arteries from pregnant as well as non-pregnant uterus. METHODS: Arteries of the uterus were obtained from both hysterectomized uterus and during pregnany hysterectomy for control group and cesarean section for pregnant group. Rings of uterine artery were suspended on muscle chambers at their optimal length for generating tension and contractile properties were examined. RESULTS: ET-1 and ET-2 induced concentration-dependent constriction of both isolated arterial strips from non-pregnant and pregnant uterus. The contraction to ET-1 and ET-2 were more enhanced in full-term pregnancy. Furthermore, in pregnant group, sarafotoxin S6c and IRL 1620, ET. agonists, induced a dose-dependent contraction, which was not shown in those from non-pregnant human. Pretreatment of human uterine arterial strips from pregnant uterus with BQ610, an ET. antagonist, for 10 min resulted in a dose-related rightward shift of ET-1 response curve with diminution of maximal response. Schild plot analysis yielded a pA value of 7.29 with a slope of 0.98. However, BQ788, an ET antagonist, did not produce any rightward shift. The contraction to lower concentration (10-8~3*10-7 M) of sarafotoxin S6c was not affected by BQ788, whereas that to higher concentration (10-s-8*10-7 M) was marked diminished. However, BQ610 did not exnt any efFect on sarafotoxin S6c-induced contraction in arterial staips from pregnant uterus. When the bath solution was replaced with Ca-free physiological salt solution (PSS) containing 1 mM EGTA for 10 min prior to adding sarafotoxin S6c, sarafotoxin S6c-induced contraction was completely abolished. Sarafotoxin S6c (10 nM)-induced contraction was prefetentially blocked by a protein kinase C antagonist, H-7, whereas it was less sensitive to a calmodulin antagonist, calmidazolium, CONCLUSION: Based on above results, we concluded that ET plays an important role in regulating uterine blood flow through the activation of ETa and ETB receptors. Furthermote, ETB receptors may predominantly contribute to the modulation of human uterine circulation in full-term pregnancy.
1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine ; Arteries* ; Baths ; Calmodulin ; Cesarean Section ; Constriction ; Egtazic Acid ; Endothelin-2 ; Endothelins* ; Female ; Humans* ; Hysterectomy ; Pregnancy ; Protein Kinase C ; Receptors, Endothelin ; Uterine Artery ; Uterus*

The aim of this study was to determine the roles of ET-1 and NO on uterine blood flow in pregnancy. Uterine arteries were isolated from 17 nonpregnant and 12 pregnant women. Nonpregnant group included patients with median age of 48.6+/-2.3 years who underwent hysterectomy, because of myoma. Pregnant group included patients with median age of 31.3+/-1.4 years undergoing cesarean delivery. ET-1 and ET-2 induced concentration-dependent contraction in isolated nonpregnant and pregnant uterine arteries. The contractile response and maximal contraction were increased in pregnant uterine arteries. In nonpregnant uterine arteries, there was no contraction in response to ET-3, whereas pregnancy induced concentration-dependent contraction by ET-3. Tissue nitrite/nitrate level and immunohistochemical staining of eNOS and iNOS were increased in pregnant uterine arteries, compared with nonpregnant uterine arteries. In addition, the expressions of eNOS and iNOS mRNA were significantly increased in pregnancy. Moreover, contractions by ET isopeptides, including ET-1, were enhanced, and immunohistochemical staining of ET-1 and ET-1 mRNA expression was increased in pregnant uterine arteries. These results suggest that NO production by increased NOS activity, especially eNOS activity, is related to placental and uterine blood flow. Furthermore, ET-1 appears to play a pathophysiological role in pregnant complications such as hypertension.
Endothelin-1* ; Endothelin-2 ; Female ; Humans* ; Hypertension ; Hysterectomy ; Myoma ; Nitric Oxide Synthase* ; Nitric Oxide* ; Pregnancy* ; Pregnant Women ; RNA, Messenger ; Uterine Artery*

PURPOSE: The enhanced expression of the cyclooxygenase-2 (COX-2), prostaglandin E2 receptor (EPs) and endothelin-1 (ET-1) axis is known to play a significant role in the development and progression of several malignancies. To date, little work has been done to investigate the relationships between the COX-2, EPs and ET-1 axis in prostate cancer (PC) cells. The aim of this study is to investigate the expression of preproET-1 (PPET-1), ET-1 receptor A (ET(A)R), and endothelin converting enzyme-1 (ECE-1) in the PC cell lines and to evaluate the effects of COX-2 and EPs on the expression of PPET-1, ET(A)R, and ECE-1. MATERIALS AND METHODS: Two PC cell lines, PC-3 and DU-145 cells were used for this study. By performing reverse transcription polymerase chain reaction (RT-PCR), the mRNA expressions of PPET-1, ET(A)R and ECE-1 were detected, and then the mRNA expressions of PPET-1, ET(A)R and ECE-1 were detected after being treating the cells with selective COX-2 inhibitor (NS-398), or EP2 (butaprost) and EP4 (misoprostol), which are both agonist of 10(-10), 10(-8) and 10(-6)M. RESULTS: PPET-1, ET(A)R and ECE-1 mRNA were expressed in both cell lines. After NS-398 treatment, only the PPET-1 mRNA expression was decreased at 4, 8 and 12 hours in the PC-3 cells. EP2 and EP4 agonist induced an increase for the PPET-1, ET(A)R and ECE-1 mRNA expressions, compared with the NS-398 treated group (control), in the PC-3 cells. CONCLUSIONS: ET-1/ET(A)R and ECE-1, whose expressions are increased by EP2 and EP4, may play key roles in the development and progression of PC via COX-2. A combination treatment with selective inhibitors for COX-2, EPs and ET(A)R would be novel approach to prostate cancer therapy.
Axis, Cervical Vertebra* ; Cell Line ; Cyclooxygenase 2* ; Dinoprostone* ; Endothelin-1 ; Endothelins* ; Polymerase Chain Reaction ; Prostate* ; Prostatic Neoplasms* ; Receptors, Prostaglandin E ; Reverse Transcription ; RNA, Messenger

OBJECTIVETo investigate the expression of bFGF, ET-1 and SCF in different passages of cultured dermal papilla cells (DPC), and their possible effect on biological behaviour of DPC.

METHODSThe expression of bFGF, ET-1 and SCF in different passages of cultured DPC was detected by immunocytochemistry and in situ hybridization.

RESULTThe expression of ET-1 and SCF in early passages of cultured DPC was stronger, but became negative in late passages (>6 passages). The stronger the expression of ET-1 and SCF in DPC, the higher ability of DPC to induce hair follicle regeneration.

CONCLUSIONThe expression strength of ET-1 and SCF is related to the ability of DPC inducing hair follicle regeneration.

Endothelin-1 ; analysis ; genetics ; Fibroblast Growth Factor 2 ; analysis ; genetics ; Hair Follicle ; chemistry ; cytology ; physiology ; Humans ; Immunohistochemistry ; In Situ Hybridization ; Stem Cell Factor ; analysis ; genetics

OBJECTIVETo investigate the effect of sodium ferulate (SF) on diabetic nephropathy (DN).

METHODSForty-eight DN patients of early stage and 54 DN patients of clinical stage were randomly divided into two groups, the conventional treatment group and the SF treatment group. Indexes, including urinary albumin excretion rate (UAER), serum endothelin (ET), blood urea nitrogen (BUN), serum creatinine (Scr) and fasting blood glucose (FBG) were observed.

RESULTSThe levels of UAER, BUN and ET were decreased in all DN patients, either early stage or clinical stage, after treated with SF for 4 weeks (P < 0.05, P < 0.01), but changed insignificantly in those treated with conventional treatment.

CONCLUSIONSF can decrease the levels of UAER and BUN in DN patients, the mechanism may relate with the decreasing of ET production and antagonizing to the binding of ET with its receptors.

Adult ; Aged ; Coumaric Acids ; therapeutic use ; Diabetes Mellitus, Type 2 ; drug therapy ; Diabetic Nephropathies ; drug therapy ; Endothelin Receptor Antagonists ; Female ; Humans ; Male ; Middle Aged ; Phytotherapy

Endothelins (ETs), which were originally found to be potent vasoactive transmitters, were known to be implicated in nervous system, but the mode of mechanism remains unclear. ETs (ET-1, ET-2, and ET-3) were added to HN33 (mouse hippocampal neuron chi neuroblastoma) cells. Among the three types of ET, only ET-1 increased the intracellular calcium levels in a PLC dependent manner with the induction of ERK 1/2 activation. As the result of ET-1 exposure, the survival rate of HN33 cells and the PKCalpha translocation into the plasma membrane were increased. We suggest that ET-1 participated in the neuroprotective effect involving the calcium-PKCalpha-ERK1/2 pathway.
Animals ; Apoptosis/*drug effects ; Calcium/*metabolism ; Cell Line ; Cell Survival/drug effects ; Cytosol/drug effects/metabolism ; Endothelin-1/*pharmacology ; Endothelin-2/pharmacology ; Endothelin-3/pharmacology ; Estrenes/pharmacology ; Extracellular Signal-Regulated MAP Kinases/*metabolism ; Immunoblotting ; Mice ; Mitogen-Activated Protein Kinase 1/metabolism ; Mitogen-Activated Protein Kinase 3/metabolism ; Neurons/*cytology/drug effects/*enzymology ; Neuroprotective Agents/pharmacology ; Phosphoproteins/metabolism ; Protein Kinase C-alpha/*metabolism ; Protein Transport/drug effects ; Pyrrolidinones/pharmacology ; Serum