• The Korean Journal of Physiology and Pharmacology
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• 제25권2호
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• pp.159-166
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• 2021

Nicotinamide adenine dinucleotide phosphate oxidases (NOXs) are the major enzymatic source of reactive oxygen species (ROS). NOX2 and NOX4 are expressed in the heart but its role in hypoxia-induced atrial natriuretic peptide (ANP) secretion is unclear. This study investigated the effect of NOX on ANP secretion induced by hypoxia in isolated beating rat atria. The results showed that hypoxia significantly upregulated NOX4 but not NOX2 expression, which was completely abolished by endothelin-1 (ET-1) type A and B receptor antagonists BQ123 (0.3 μM) and BQ788 (0.3 μM). ET-1-upregulated NOX4 expression was also blocked by antagonists of secreted phospholipase A2 (sPLA2; varespladib, 5.0 μM) and cytosolic PLA2 (cPLA2; CAY10650, 120.0 nM), and ET-1-induced cPLA2 expression was inhibited by varespladib under normoxia. Moreover, hypoxia-increased ANP secretion was evidently attenuated by the NOX4 antagonist GLX351322 (35.0 μM) and inhibitor of ROS N-Acetyl-D-cysteine (NAC, 15.0 mM), and hypoxia-increased production of ROS was blocked by GLX351322. In addition, hypoxia markedly upregulated Src expression, which was blocked by ET receptors, NOX4, and ROS antagonists. ET-1-increased Src expression was also inhibited by NAC under normoxia. Furthermore, hypoxia-activated extracellular signal-regulated kinase 1/2 (ERK1/2) and protein kinase B (Akt) were completely abolished by Src inhibitor 1 (1.0 μM), and hypoxia-increased GATA4 was inhibited by the ERK1/2 and Akt antagonists PD98059 (10.0 μM) and LY294002 (10.0 μM), respectively. However, hypoxia-induced ANP secretion was substantially inhibited by Src inhibitor. These results indicate that NOX4/Src modulated by ET-1 regulates ANP secretion by activating ERK1/2 and Akt/GATA4 signaling in isolated beating rat hypoxic atria.

• Tuberculosis and Respiratory Diseases
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• 제44권4호
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• pp.844-852
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• 1997

연구배경 : 최근의 기관지천식 병인과 관련한 여러 연구에서 천식 발작중에 폐장에서 과도하게 유리된 endothelin(ET)이 기관지 수축을 유발시키는 주요한 펩티드임이 확인되었다. 이 연구의 목적은 급성발작의 경과에 따른 혈장 몇 요중치의 변동 및 상호 연관성을 관찰함에 있다. 방 법 : 연구대상은 16명의 급성 천식악화로 입원한 환자에서 내원당일과 치료 2주후의 2회의 혈장 및 24시간 요를 채취하였다. 정상대조군은 신체건강한 성인 10명으로 정하였다. 모든 천식환자는 입원당시 부신피질호르몬제, 베타-2 교감신경작동제, 아미노필린 제제를 투약받았다. ET은 방사면역측정법에 외해 측정되었으며 교차반응성에 있어 ET-1과는 100%, ET-2와 67%, ET-3와 84%, Big-ET과 8% 이었다. 결 과 : 혈장 ET은 천식환자의 및대조군의 수치와 비교하여 천식악화시 유의하게 증가하였다. 그러나 요중 ET은 천식악화시 및 치료후에 유의한 감소가 관찰되지 않았으나 정상대조군에 비해서는 둘다 유의하게 증가되어 있었다. 혈중 및 요중 ET치는 폐기능 및 저산소혈증 등과 유의한 상관관계는 없었다. 결 론 : 천식의 급성악화시에 증가한 혈장의 ET은 폐장에서의 ET 유리의 증가에 기인한 것으로 사료된다. 천식발작 환자는 정상인에 비해 요중 ET의 배설이 증가하여 있었으나 치료 2주후까지는 유의한 감소가 관찰되지 않았다. 따라서 천식발작시의 요중 ET의 변동을 관찰하기 위해서는 좀더 긴 관찰기간 및 많은 환자를 대상으로 포괄적인 연구가 되어야 할 것으로 생각된다.

• Biomolecules & Therapeutics
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• 제12권2호
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• pp.62-67
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• 2004

Trauma remains one of the important sources leading to systemic inflammatory response anti sub-sequent multiple organ failure. Although hepatic microvascular dysfunction occurs during trauma, the mechanism responsible remains unclear. The aim of this study was to investigate the effect of trauma on hepatic vascular stress gene expression. Femur fracture (EFx) was induced by torsion to the femur at midshaft. Liver samples were taken for RT-PCR analysis of mRNA for gtenes of interest: endothelin-1 (ET-1), its receptors $ET_A$ and $ET_B$, nitric oxide synthases (iNOS and eNOS), cyclooxygenase-2 (COX-2), heme oxygenase-1 (HO-1), and tumor necrosis tactor-${\alpha}$ (TNF-${\alpha}$). The expression of ET-1 mRNA was significantly increased by FFx. Expression of mRNA in FFx group showed no change in $ET_A$, $ET_B$, iNOS and HO-1 and showed a slight increase of 2.2-fold and 2.7-fold for eNOS tll1d COX-2, respectively. The level of TNF-${\alpha}$ mRNA significantly increased in FFx group. In conclusion, mild trauma alone causes little change in expression of vasoactive mediators.

• Tuberculosis and Respiratory Diseases
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• 제50권2호
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• pp.182-195
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• 2001

연구배경 : IPF에 의한 유병률과 사망률은 점차 증가하는 추세이나 좋은 치료는 없는 상태이다. 폐 섬유화 과정에서 TGF-${\beta}_1$, TNF-$\alpha$, ET-1, IFN-$\gamma$등의 사이토카인이 중요한 역할을 함이 알려져 있다. 본 실험은 파라콰트를 기관지 내로 주입하여 섬유화가 유발되는 과정의 백서의 폐 조직 내에서 ET-1과 TGF-${\beta}_1$의 발현을 살펴보고, 또한 비선택적 ET-1 receptor blocker인 Bosentan이 폐 섬유화의 치료에 효과가 있는지를 보고자 하였다. 방 법 : 웅성 7-8 주령의 백서 120 마리를 세 그룹으로 나누고 제 1그룹은 대조군으로 하여 기관지 내로 생리 식염수를 투여하였고, 제2그룹은 파라콰트를 투여하였으며, 제3그룹은 첫날 파라콰트를 투여한 후 매일 gastric gavage 방법으로 보센탄을 투여하였다. 파라콰트 혹은 생리식염수를 투여한 지 1, 3, 5, 7, 10, 14일째 각각 세 그룹의 일정 수를 희생하여 폐의 병리조직을 보고 면역세포화학염색으로 ET-1과 TGF-${\beta}_1$의 발현 율을 조사하여 분석하였다. 폐 섬유화의 정도는 H&E 염색과 Masson trichrome 염색을 하여 컴퓨터 영상분석을 시행하였고, 면역세포화학염색은 염색정도에 따라 반정량화하여 분석하였다. 결 과 : 파라콰트를 투여한 군이 대조군에 비해 콜라겐의 침착이 실험 3일째부터 현저히 증가하였고, ET-1과 TGF-${\beta}_1$의 발현이 주로 실험 초기에 증가하였다. 그러나 보센탄을 투여한 경우 콜라겐이 침착된 양에는 유의한 변화가 없었고 파라콰트군과 비교해서 ET-1과 TGF-${\beta}_1$의 발현에 뚜렷한 변화는 없었다. 결 론: 파라콰트를 투여한 경우 폐 섬유화가 증가하였다. 그리고 ET-1과 TGF-${\beta}_1$의 발현이 증가하였다. 그러나 ET-1 에 대한 receptor blocker인 보센탄이 폐 섬유화를 막지는 못하였다. 파라콰트에 의한 폐 섬유화에 ET-1이 연관성이 있으나 그 역할에 대해서는 추후 더 연구가 필요할 것으로 사료된다.

• 한국생물물리학회:학술대회논문집
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• 한국생물물리학회 1998년도 학술발표회
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• pp.37-37
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• 1998

Effects of endothelin-l (ET-l) on contraction, $Ca^{2＋}$ transient and L -type $Ca^{2＋}$ current ( $I_{Ca,L}$) were investigated in single ventricular myocytes isolated from guinea-pig hearts. ET-l at concentrations of 5 and 10 nM produced a biphasic pattern of inotropism： a first decrease in contraction by 34.4$\pm$2.5 ％ of the control followed by a sustained increase in contraction by 66.6$\pm$8.4% (mean$\pm$S.E.M., n=9).(omitted)

• The Korean Journal of Physiology and Pharmacology
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• 제20권1호
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• pp.9-14
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• 2016

Adenosine 3',5'-cyclic monophosphate (cAMP) participates in the regulation of numerous cellular functions, including the $Na^+-K^+$-ATPase (sodium pump). Ouabain, used in the treatment of several heart diseases, is known to increase cAMP levels but its effects on the atrium are not understood. The aim of the present study was to examine the effect of ouabain on the regulation of atrial cAMP production and its roles in atrial endothelin-1 (ET-1) secretion in isolated perfused beating rabbit atria. Our results showed that ouabain ($3.0{\mu}mol/L$) significantly increased atrial dynamics and cAMP levels during recovery period. The ouabain-increased atrial dynamics was blocked by KB-R7943 ($3.0{\mu}mol/L$), an inhibitor for reverse mode of $Na^+-Ca^{2+}$ exchangers (NCX), but did not by L-type $Ca^{2+}$ channel blocker nifedipine ($1.0{\mu}mol/L$) or protein kinase A (PKA) selective inhibitor H-89 ($3.0{\mu}mol/L$). Ouabain also enhanced atrial intracellular cAMP production in response to forskolin and theophyline ($100.0{\mu}mol/L$), an inhibitor of phosphodiesterase, potentiated the ouabain-induced increase in cAMP. Ouabain and 8-Bromo-cAMP ($0.5{\mu}mol/L$) markedly increased atrial ET-1 secretion, which was blocked by H-89 and by PD98059 ($30{\mu}mol/L$), an inhibitor of extracellular-signal-regulated kinase (ERK) without changing ouabain-induced atrial dynamics. Our results demonstrated that ouabain increases atrial cAMP levels and promotes atrial ET-1 secretion via the mitogen-activated protein kinase (MAPK)/ERK signaling pathway. These findings may explain the development of cardiac hypertrophy in response to digitalis-like compounds.

• Archives of Pharmacal Research
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• 제24권1호
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• pp.64-68
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• 2001

Endothelin-1 (ET-1 ), a novel and potent vasoconstrictor in blood vessel, is known to have some functions in the rat central nervous system (CNS), In order to investigate the central functions of ET-1 , ET-1 was administered to the periaqueductal gray area (PAC) of anesthetized rats to induce barrel rolling and increase the arterial blood pressure (ABP). ET-1 had a modulatory effect on central cardiovascular and behavioral control. The selective N-methyl-D-aspartate (NMDA) receptor antagonist MK-801 (3${u}m/ol/kg$, i.p.) blocked the ET-1 induced responses, and both the nitric oxide synthase (NOS) inhibitor L-NAME (N-nitro-L-arginine mIThyl-ester 1 nmol/rat) and the nitric oxide (NO) scavenger hemoglobin (15 nmol/rat) had similar effects in redtAcing the IT-1 (10 pmol/rat)-induced behavioral changes and ABP elevation. However, NO donor sodium nitroprusside (SNP 10${u}g$, 1${u}g/rat$) decreased the ET-1 induced ABP elevation, and recovered the ET-1 -induced barrel rolling effect that was reduced by MK-801. These results suggest that ET-1 might have neuromodulatory functions such as ABP elevation and barrel rolling induction in the PAG of the rats via the NMDA receptor and NO.

• Journal of Genetic Medicine
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• 제5권1호
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• pp.34-40
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• 2008

목 적 : 자간전증은 임신부와 신생아의 사망 및 이환의 주된 원인으로 유전적 소질과 환경적 요인에 의해 발생하는 다요인성 질환이다. ET-1은 강력한 혈관수축 펩티드로 ET-1 시스템 내의 변경이 자간전증에서의 혈관수축을 자극하는 것으로 생각되고 있다. 본 연구에서는 정상 임신부와 자간전증 임신부에서 ET-1 유전자의 4가지 단일염기다형성들(c.1370T>G, c.137_139delinsA, c.3539+2T>C, and c.5665G >T)의 양상을 조사하여 비교함으로써 이러한 유전자 다형성들과 한국인 자간전증의 연관성에 대하여 알아보고자 하였다. 방 법 : 자간전증 임신부 206명과 임신기간 동안 자간전증이 발생하지 않은 정상 임신부 216명의 혈액으로부터 DNA를 추출하고 ET-1 유전자 다형성들의 양상을 SNapShot kit와 ABI Prism 3100 Genetic analyzer를 사용하여 분석하였다. 결 과 : 자간전증 환자군에서 ET-1 유전자의 4가지 단일 염기다형성 각각의 유전자형 및 대립유전자의 빈도는 대조군과 유의한 차이가 없었다. 또한 자간전증 환자군에서 3가지 일배체형(TDTG, GDCT, and TICT)의 빈도도 대조군과 유의한 차이가 없었다: 61%(TDTG), 13%(GDCT), 13%(TICT) vs. 62%, 14%, 12%. 나이, 미산부률, 분만주수, 신체질량지수 등의 자간전증 발생요인을 공변량으로 하여 유전자형과 자간전증 발생의 위험도 사이의 연관성을 확인하기 위해 다중회귀분석을 시행한 결과 열성모델과 우성모델에서 모두 ET-1 유전자의 단일염기다형성들에 대한 자간전증 발생의 위험도가 증가하지 않았다. 결 론 : 한국인 임신부에서 ET-1 유전자의 4가지 단일염기 다형성들은 자간전증 발생과 연관이 없는 것으로 사료된다.

• Biomolecules & Therapeutics
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• 제16권4호
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• pp.306-311
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• 2008

Although hepatic microcirculatory dysfunction occurs during endotoxemia, the mechanism responsible for this remains unclear. Since Kupffer cells provide signals that regulate hepatic response in inflammation, this study was designed to investigate the role of Kupffer cells in the imbalance in the expression of vasoactive mediators. Endotoxemia was induced by intraperitoneal E. coli endotoxin (LPS, 1 mg/kg body weight). Kupffer cells were inactivated with gadolinium chloride ($GdCl_3$, 7.5 mg/kg body weight, intravenously) 2 days prior to LPS exposure. Liver samples were taken 6 h following LPS exposure for RT-PCR analysis of mRNA for genes of interest: endothelin (ET-1), its receptors $ET_A$ and $ET_B$, inducible nitric oxide synthase (iNOS), heme oxygenase (HO-1), and tumor necrosis factor-$\alpha$ (TNF-$\alpha$). mRNA levels for iNOS and TNF-$\alpha$ were significantly increased 31.8-fold and 26.7-fold in LPS-treated animals, respectively. This increase was markedly attenuated by $GdCl_3$, HO-1 expression significantly increased in LPS-treated animals, with no significant difference between saline and $GdCl_3$ groups. ET-1 was increased by LPS. mRNA levels for $ET_A$ receptor showed no change, whereas $ET_B$ transcripts increased in LPS-treated animals. The increase in $ET_B$ transcripts was potentiated by $GdCl_3$. We conclude that activation of Kupffer cells plays an important role in the imbalanced hepatic vasoregulatory gene expression induced by endotoxin.

• Molecules and Cells
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• 제22권1호
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• pp.44-50
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• 2006

We investigated the possible role of p38 MAPK and $ET_B$ receptors in ET-1 induction of cyclooxygenase-2 (COX-2) and prostaglandin $E_2$ ($PGE_2$) in cultured feline esophageal smooth muscle cells (ESMC). Confluent layers of ESMC were stimulated with 10 nM ET-1 and expression of COX-1 and COX-2, involvement of receptors, and activation of p38 MAPK, were examined by Western blot analysis. Levels of $PGE_2$ induced by ET-1 were measured by Elisa. Using $ET_A$and $ET_B$ antagonists (BQ-123 and BQ-788, respectively), the contribution of the ET receptors to COX-1 and COX-2 expression induced by ET-1 was determined. Western blot analysis revealed that treatment of ESMC with ET-1 resulted in transient expression of COX-2 and activation of p38 MAPK. Activation of p38 MAPK was maximal after 1 h. SB202190, a p38 MAPK inhibitor, reduced expression of COX-2, but not COX-1. ET-1-induced release of $PGE_2$ was also blocked by SB202190. COX-2 expression was upregulated only via the $ET_B$ receptor, and COX-1 expression was not affected by either antagonist. Taken together, our data suggest that ET-1 causes p38 MAPK-dependent expression of COX-2 by interacting with $ET_B$ receptors on ESMC.