肾上腺髓质素及受体在肾上腺和嗜铬细胞瘤中的表达

目的研究肾上腺髓质素(ADM)及其特异性受体-受体活性调节蛋白2/降钙素受体样受体(RAMP2/CRLR)mRNA在正常肾上腺髓质和嗜铬细胞瘤组织中的表达。方法提取8例正常肾上腺髓质和18例嗜铬细胞瘤组织总RNA,行逆转录-聚合酶链反应,以扩增的ADM、RAMP2、CRLR条带灰度与内参照GAPDH条带灰度比值进行半定量分析。结果正常肾上腺髓质和嗜铬细胞瘤组织中均可见ADM及其特异性受体RAMP2/CRLRmRNA的表达,其ADM/GAPDH分别为0.48±0.09和0.75±0.24,RAMP2/GAPDH分别为0.79±0.12和1.29±0.30,CRLR/GAPDH分别为0.40±0.08和0.87±0.22,嗜铬细胞瘤组织中ADM及其特异性受体RAMP2/CRLRmRNA的表达显著高于正常肾上腺髓质(P<0.05)。结论ADM可能通过自分泌或旁分泌方式作用于肾上腺局部,在嗜铬细胞瘤的发生发展中起一定的作用。

钙化血管平滑肌细胞肾上腺髓质素及其受体系统的基因表达上调

探讨钙化的血管平滑肌细胞肾上腺髓质素生成和肾上腺髓质素受体系统一降钙素受体样受体和受体活性修饰蛋白基因表达的改变及其病理意义。采用β-甘油磷酸盐诱导培养的大鼠血管平滑肌细胞钙化;放射免疫法测定血管平滑肌细胞分泌的肾上腺髓质素含量;半定量逆转录聚合酶链反应测定细胞肾上腺髓质素、降钙素受体样受体和受体活性修饰蛋白的mRNA水平;原子吸收分光光度计测定细胞钙含量;碱性磷酸酶试剂盒测定血管平滑肌细胞碱性磷酸酶活性;β液体闪烁计数仪测定45Ca2+放射活性。结果发现,与非钙化血管平滑肌细胞比较,钙化血管平滑肌细胞内钙含量、45Ca2+摄入及碱性磷酸酶活性分别增加118％、174％和7倍(P<0.01);钙化细胞肾上腺髓质素分泌量增高99％(P<0.01),肾上腺髓质素、降钙素受体样受体、受体活性修饰蛋白2和3的mRNA水平分别增加78％、93.7％、91.8％和109.5％(P均<0.01)。肾上腺髓质素与降钙素受体样受体、受体活性修饰蛋白2和3的mRNA水平呈正相关,其相关系数分别为0.83、0.92和0.93(P均<0.01)。结果提示,血管平滑肌细胞肾上腺髓质素 旁/自分泌功能改变可能参与血管钙化的调节过程。

高血压病患者血浆肾上腺髓质素水平及药物干预反应

循环系统不仅是血液流动和物质交换的通道，也是一个内分泌器官，可产生和分泌多种生物活性物质。肾上腺髓质素（Ａｄｒｅｎｏｍｅｄｕｌｉｎ，ＡＤＭ）是日本学者１９９３年发现的一种新的血管活性多肽，广泛分布于机体肾上腺、肾脏、肺和心血管组织，具有较强的血管扩张...

肾上腺髓质素前体N端20肽对组胺诱发豚鼠支气管痉挛的作用

肾上腺髓质素前体Ｎ端２０肽对组胺诱发豚鼠支气管痉挛的作用郭德玉李三龙于晓岚姬志娟李斌盛树力肾上腺髓质素的前体蛋白由１８５个氨基酸组成，在裂解酶的作用下，裂解为许多片段，其中有一个独特的在Ｎ端区含２０个氨基酸的残基，被称为肾上腺髓质素前体Ｎ端２０肽（Ｐ...

Effect of adrenomedullin on neuron apoptosis, infarction volume and expression of Egr-1 mRNA after focal ischemia-reperfusion in rats

Objective To observe the influence of adrenomedullin （ADM） on neuron apoptosis, infarction volume of brain, and the expression of early growth response 1 （Egr-1） mRNA in ischemia-reperfusion rats. Methods The arteria cerebri media was tied for 2 h to construct the ischemia model. Infarction volume was detected by triphenltetrazolium chloride （T＇I＇C） staining, neuronal apoptosis and necrosis was detected with terminal deoxynucleotidyl transferase nick labeling （TUNEL） method, and the Egr-1 mRNA expression was examined by in situ hybridization （ISH）. Results Infarction volume after ischemia-reperfusion is （269 ± 20） mm^3. Infarction volume after injection of ADM through different ways are femoral vein （239 ± 17） mm^3 （decreased by 11.2%）, arteria carotis （214 ± 14） mm^3 （by 20.4%） and lateral cerebral ventricle （209 ± 13） mm^3 （by 22.3%）, respectively. The results indicate that injecting ADM through arteria carotis and lateral cerebral ventricle is much more effective than it through femoral vein （P 〈 0.05）. The TUNEL-positive cells in cerebral cortex or hippocampus are few in the sham operation group, but much more in the ischemia-reperfusion group. After being supplied with ADM, especially through arteria carotis interna or lateral cerebral ventricle way, the TUNEL-positive cells decreased obviously. Expression of Egr- 1 mRNA was low in the cerebral cortex of the sham operation group rats, enhanced in the ischemia and reperfusion group rats, and enhanced markedly after treatment with ADM, especially through arteria carotis interna or lateral cerebral ventricle way （P 〈 0.01）. Conclusion Injection of ADM through different ways could alleviate neural dysfunction, decrease neuron apoptosis and brain infarction volume, and increase the expression of Egr- 1 mRNA.

Effects of continuous intermedin infusion on blood pressure and hemodynamic function in spontaneously hypertensive rats

Objective To examine the effects of exogenously administered intermedin （IMD,adrenomedullin-2） on arterial blood pressure,cardiac function and the cardiovascular IMD receptor system in spontaneously hypertensive rats （SHRs） as well as to investigate the associated mechanisms.Methods Thirteen week-old male rats were divided in Wistar Kyoto （WKY） group （n =12）,SHR group （n =12）,IMD group （SHRs infused with IMD 1-47 500 ng/kg per hour,n =12）,and ADM group （SHRs infused with adrenomedullin 500 ng/kg per hour,n =12）.Results A two-week continuous administration of low dose IMD 1-47 via mini-osmotic pumps markedly reduced blood pressure,the maximal rates of increase and decrease of left-ventricle pressure development （LV ± dp/dtmax）,left ventricular systolic pressure and heart rate in SHRs.Furthermore,IMD also inhibited protein over-expression of cardiovascular IMD receptors,myocardial Receptor Activity-Modifying Proteins （RAMP1 and RAMP2）,aortic RAMP1,RAMP2,RAMP3,and calcitonin receptor-like receptor （CRLR）;suppressed up-regulation of aortic RAMP1,RAMP2,RAMP3 and CRLR gene expression; and markedly elevated the mRNA abundance of myocardial atrial natriuretic peptide （ANP） and myocardial brain natriuretic peptide （BNP）.Additionally,IMD 1-47 administration in SHRs increased aortic cAMP concentration and reduced myocardial cAMP concentration.Conclusion These findings support the speculation that IMD,as a cardiovascular active peptide,is involved in blood pressure reduction and cardiac function amelioration during hypertension.The mechanism underlying this effect may involve IMD binding of a receptor complex formed by RAMPs and CRLR,and consequential regulation of cAMP levels and other cardiovascular active factors,such as ANP and BNP.

Effects of adrenomedullin gene overexpression on biological behavior of hepatic stellate cells

AIM: To investigate the effects of adrenomedullin (AM) gene overexpression on the biological characteristics of human hepatic stellate cells (hHSCs) by stable transfection.METHODS: hHSCs which express low basal levels of AM were stably transfected with an expression construct containing rat AM gene or with an empty expression vector. Expression of AM in hHSCs was determined by reverse transcription (RT)-polymerase chain reaction (PCR) and radioimmunoassay (RIA). Cell proliferation was evaluated by 5-bromo-2'-deoxyuridine (BrdU) incorporation and immunocytochemistry. RT-PCR and Western blot were used to test the expression of procollagen types Ⅰ and Ⅲ. Protein expressions of interstitial collagenase (MMP-1), gelatinase (MMP-2) and tissue inhibitors of matrix metalloproteinases-2 (TIMP-2) were assessed by Western blot.RESULTS: Two cell clones (A-2, A-8) transfected withthe AM gene expressed higher levels of AM mRNA (nontransfected group: 0.86±0.11, empty vector group: 1.01±0.11, A-2 clone group: 1.44±0.08 and A-8 clone group: 1.36±0.05) and protein (12.31±0.17, 12.35±0.12,12.56±0.06 and 12.62±0.07) (P＜0.05). AM geneoverexpression had inhibitory effects on cell proliferation of hHSCs (29.6%, 30.9%, 18.9% and 21.8%, respectively. P＜0.05) and expression of procollagen type Ⅰ (0.58±0.1,0.48±0.11, 0.3±0.06 and 0.31±0.07 at mRNA level)(0.27±0.07, 0.3±0.06, 0.14±0.05 and 0.13±0.05 at protein level) (P＜0.05) and procollagen type Ⅲ (0.17±0.04, 0.15±0.03, 0.1±0.02 and 0.09±0.02 at mRNA level) (0.22±0.04, 0.2±0.03, 0.11±0.04 and 0.13±0.03 at protein level) (P＜0.05). Compared with cells non-transfected (TIMp2: 2.77±0.03, MMP-2: 0.5±0.04, MMP-1: 0.49±0.07) and transfected with empty vector (TIMP2: 2.79±0.04,MMP-2: 0.48±0.03, MMP-1: 0.45±0.09), these two clones had lower expression levels of TIMP2(A-2 clone group: 2.7±0.02 and A-8 clone group: 2.71±0.02) (P＜0.05) and MMP-2(A-2 clone group: 0.15±0.05 and A-8 clone group: 0.13±0.04) (P＜0.05) but displayed a higher expression level of MMP-1(A-2 clone group: 0.68±0.06 and A-8 clone group: 0.81±0.09) (P＜0.05).CONCLUSION: AM gene exerts negative influence to some extent on hHSCs by inhibiting proliferation and production of extracellular matrix (ECM) in addition to inducing MMP-1 expression.

Expression of adrenomedullin and its receptor in lungs of rats with hypoxic pulmonary hypertension

OBJECTIVE: To investigate the role of adrenomedullin (AM) in the development of hypoxic pulmonary hypertension (HPH), and to assess the expression of AM and adrenomedullin receptor (AMR) in the lungs of rats with HPH. METHODS: We exposed 10 rats to normobaric hypoxic conditions for 3 weeks to establish rat model of pulmonary hypertension; and 10 other rats were used as normoxic controls. Mean pulmonary arterial pressure (mPAP) was measured by a right cardiac catheterization. The thickness of pulmonary arterioles was measured by a computerized image analyzer. We used the reverse transcription-polymerase chain reaction (RT-PCR) to assess the change of expression of AM and AMR in lung of HPH rat model. RESULTS: Compared with the control group, hypoxic rats developed remarkable pulmonary hypertension, increment in the thickness of pulmonary arterioles and right ventricular hypertrophy (P

Prediction about severity and outcome of sepsis by proatrial natriuretic peptide and pro-adrenomedullin

Objective： Measurement of biomarkers is a potential approach to early prediction of the risk of mortality in patients with sepsis. The aim of the present study was to evaluate the prognostic value of pro-atrial natriuretic peptide （pro-ANP） and pro-adrenomedullin （pro- ADM） levels in a cohort of medical intensive care patients and to compare it with that of other known biomarkers and physiological scores. Methods： Blood samples of 51 consecutive critically ill patients admitted to the intensive care unit and 53 age-matched healthy control people were evaluated in this prospective study. The prognostic value ofpro-ANP and pro-ADM levels was compared with that of acute physiology and chronic health evaluation （APACHE） II scores and various biomarkers such as C-reactive protein, interleukin-6 and procalcitonin. Pro-ANP and pro-ADM were detected by a new sandwich immunoassay. Results： On admission, 25 patients had systemic inflammatory response syndrome （SIRS）, 12 sepsis, 9 severe sepsis and 5 septic shock. At that time, the median levels （ng/ml） of pro-ANP and pro-ADM were 87.22 and 0.34 respectively in patients with SIRS, 1533.30 and 2.23 in those with sepsis, 1098.73 and 4.57 in those with severe sepsis, and 1933.94 and 8.21 in those with septic shock. With the increasing severity of disease, the levels of pro- ANP and pro-ADM were gradually increased. On admission, the circulating levels ofpro-ANP and pro-ADM in patients with sepsis, severe sepsis, or septic shock were significantly higher in non-survivors than in survivors （P〈0.05）. In a receiver operating characteristic curve analysis for the survival of patients with sepsis, the areas under the curve （AUCs） for pro-ANP and pro-ADM were 0.89 and 0.87 respectively, which was similar to the AUCs for procalcitonin and APACHE II scores. Conclusion： Pro-ANP and pro-ADM are valuable biomarkers for prediction of severity of septic patients.