Effect of endoplasmic reticulum stress on the activation of high glucose-induced monocytes

Objective To observe the effects of endoplasmic reticulum stress (ERS) on the activation of monocytes induced by high glucose and explore the underlying mechanism. Methods The monocyte cell line THP-1 was stimulated with high glucose, and then treated with molecular chaperone betaine. The levels of glucose regulation protein 78 (GRP78) and p-JNK, which were associated with ERS were detected by real-time PCR and Western blotting. The proliferation of the cell line was detected by MTT method. Transwell and immunofluorescence were applied to observe the chemotaxis and phenotype of cells respectively. Results The levels of GRP78 and p-JNK of THP-1 cells stimulated by high glucose were significantly increased compared with the normal control group (all P＜0.05). The proliferation and chemotactic were also enhanced (all P＜0.05). The number of cells in M1 phenotype was increased remarkably (P＜0.05). All the indexes above could be rescued by betaine. Conclusion The activation of THP-1 cells can be induced by high glucose through ERS, while molecular chaperone betaine can reverse the activation.     

环氧化酶-2在缺血性脑损伤过程中的表达及其作用机制

环氧化酶是花生四烯酸代谢中的关键酶.其诱导型(COX-2)受多种致病因子调节,在白细胞和脑中表达.近年来研究表明,COX-2对神经系统损伤具有调控作用,其作用机制可能涉及炎症反应与自由基损伤、组织低灌流以及对神经元的直接损伤.现就COX-2在中枢神经系统中的表达及其参与缺血性脑损伤作用的机制作一综述.     

厄贝沙坦对高糖诱导的小鼠足细胞瞬时受体电位阳离子通道蛋白6表达的影响

目的研究血管紧张素Ⅱ受体拮抗剂(angiotensinⅡreceptor blockers,ARB)厄贝沙坦对高糖诱导的条件永生化小鼠足细胞瞬时受体电位阳离子通道蛋白6(transient receptor potential cation channel,TRPC6)表达的影响。方法首先体外培养条件永生化小鼠足细胞,分为高渗对照组(甘露醇30 mmol/L+葡萄糖5 mmol/L),正常对照组(葡萄糖5 mmol/L)、实验组(葡萄糖浓度分别为15 mmol/L、25 mmol/L和35 mmol/L),免疫细胞化学检测小鼠足细胞TRPC6分布,Western Blot和RT-PCR分别检测小鼠足细胞TRPC6蛋白和mRNA的表达;其次使用高糖(25 mmol/L)在不同时间点(0 h,12 h,24 h,48 h)作用于足细胞,Western Blot和RT-PCR分别检测小鼠足细胞TRPC6蛋白和mRNA的表达;最后将细胞分为5组:正常对照组、高糖组、高糖+厄贝沙坦组(10~(-7)mol/L)、高糖+厄贝沙坦组(10~(-6)mol/L)、高糖+厄贝沙坦组(10~(-5)mol/L),倒置显微镜下观察不同浓度厄贝沙坦对高糖诱导的足细胞形态学变化,Western Blot和RT-PCR分别检测小鼠足细胞TRPC6蛋白和mRNA的表达。结果①免疫细胞化学检测可见,随着葡萄糖浓度的增加,TRPC6主要集中表达于足细胞胞膜,沿足突分布更加明显;Western Blot和RT-PCR检测到TRPC6蛋白和mRNA表达量逐渐增加,以25 mmol/L变化最明显。②高糖刺激足细胞后,与0h比较,随着刺激时间的延长,足细胞TRPC6蛋白和mRNA表达量明显增加(P0.05),在48 h达到高峰,呈一定的时间依赖性。③与正常对照组比较,高糖诱导的TRPC6表达明显增高(P0.05)。与高糖组比较,高糖+厄贝沙坦组随厄贝沙坦浓度的增加,TRPC6蛋白和mRNA表达量明显下调(P0.05),呈浓度依赖性。结论高糖可诱导足细胞TRPC6表达增加,厄贝沙坦对高糖诱导的足细胞损伤具有保护作用,其机制可能是通过下调足细胞TRPC6的表达来实现的。     

Furosemide stimulates macula densa cyclooxygenase-2 expression in rats

BACKGROUND: During a low salt intake, maintenance of renal blood flow and renin secretion depends on intact formation of prostaglandins. In the juxtaglomerular apparatus, the inducible isoform of cyclooxygenase, cyclooxygenase-2 (COX-2), is restricted to the macula densa and the cortical thick ascending limb of Henle (cTALH) cells, and is inversely regulated by dietary salt intake. This study aimed to elucidate whether the effect of NaCl on macula densa COX-2 expression is mediated by transepithelial transport of NaCl. METHODS: To this end, male Sprague-Dawley rats received subcutaneous infusions of the loop diuretic furosemide (12 mg/day) or were fed with the diuretic hydrochlorothiazide (30 mg/kg day) for seven days each. To compensate for their salt and water loss, the animals had free access to normal water and to salt water (0.9% NaCl, 0.1% KCl). COX-2 expression in kidney cortex was assessed by immunohistochemical staining and by semiquantitative ribonuclease protection assay for COX-2 mRNA. RESULTS: After six days of furosemide infusion to salt-substituted rats, there was no change of extracellular volume. Furosemide led to a fivefold and threefold increase of plasma renin activity and renocortical renin mRNA level, respectively. In parallel, there was a threefold increase of renocortical COX-2 abundance, while the COX-1 mRNA level remained unchanged. Moreover, the percentage of juxtaglomerular apparatuses immunopositive for COX-2 increased threefold in response to furosemide compared with vehicle-infused animals. Hydrochlorothiazide treatment increased plasma renin activity twofold but did not change kidney cortical renin mRNA, COX-2 mRNA, or COX-2 immunoreactivity. CONCLUSION: Our findings suggest that inhibition of salt transport in the loop of Henle, but not in the distal tubule, causes a selective stimulation of COX-2 expression in the macula densa region. This up-regulation may be of relevance for macula densa signaling, which links tubular salt transport rate with glomerular filtration rate and renin secretion.     

环氧合酶-2在肝细胞癌中的表达及其临床意义

目的　检测正常肝脏、慢性肝炎、肝硬化、肝细胞癌组织中COX 2基因的表达 ,并分析COX 2基因在肝细胞癌中表达的临床意义。方法　利用免疫组织化学方法检测 110例肝细胞癌组织中COX 2基因的表达 ,并以 5例正常肝组织 ,12例慢性乙型肝炎组织 ,15例肝硬化组织为对照 ,比较其中COX 2基因表达的差异。结果　正常肝组织、慢性肝炎组织、肝硬化组织、肝细胞癌组织中COX 2的表达率分别为 0 %、3 3 .3 %、46.7%和 64 .7% ,肝细胞癌组织中的表达明显上调 ,且呈“不表达 中度表达 高表达”之势。结论　COX 2基因在肝炎 肝硬化 肝癌的演变过程中起着某种作用 ,参与了肝细胞癌发生、发展、侵袭、转移的全过程。     

Cyclosporine A suppresses cyclooxygenase-2 expression in the rat kidney

On the basis of recent evidence that the cyclooxygenase-2 (COX-2) gene promoter contains functional binding sites for the nuclear factor of activated T cells (NFAT) and that COX-2 is expressed in a regulated fashion in the kidney, this study aimed to assess the effect of immunosuppressants on COX-2 expression in the kidney. Therefore, Wistar-Kyoto rats were treated with cyclosporine A (CsA; 15 mg/kg per day) or tacrolimus (5 mg/kg per day) for 7 d each. Both drugs markedly lowered COX-2 expression while COX-1 expression remained unaltered. Furthermore, CsA blunted the increase of renocortical COX-2 expression in response to low salt intake or a combination of low-salt diet with the ACE inhibitor ramipril (10 mg/kg per day), which strongly stimulates renocortical COX-2 expression. At the same time, calcineurin inhibitors moderately enhanced basal as well as stimulated renin secretion and renin gene expression. These findings suggest that inhibition of calcineurin could be a crucial determinant for the regulated expression of COX-2 in the kidney. Inhibition of COX-2 expression may therefore at least in part account for the well-known adverse effects of immunosuppressants in the kidney. Moreover, our data suggest that the stimulation of the renin system by low salt and by ACE inhibitors is not essentially mediated by COX-2 activity.     

氯沙坦通过ERK1/2丝裂原活化蛋白激酶途径抑制高糖诱导的小鼠系膜细胞结缔组织生长因子表达

糖尿病肾病(DN)是糖尿病严重的慢性并发症之一,其主要病理特征是由细胞外基质(ECM)增多引起的肾小球硬化.血管紧张素(Ang)受体拮抗剂氯沙坦可有效地延缓肾小球硬化,被用于DN的治疗.高糖可诱导肾脏系膜细胞结缔组织生长因子(CTGF)的表达,从而促进ECM积聚和组织器官的纤维化.丝裂原活化蛋门激酶(MAPK)作为真核细胞胞质内的信号转导终末通路,与DN的发病密切相关[1].本研究观察高糖是否通过ERK1/2 MAPK途径调节小鼠系膜细胞CTGF的表达,以及氯沙坦对CTGF的作用是否也与ERK1/2 MAPK通路相关.     

Role of high glucose-induced nuclear factor-kappaB activation in monocyte chemoattractant protein-1 expression by mesangial cells

Although high glucose (HG) has been shown to induce nuclear factor-kappaB (NF-kappaB) activation in vascular cells, the upstream regulation and the biologic significance of NF-kappaB activation in diabetic renal injury are not clear. It was, therefore, examined if HG-induced generation of reactive oxygen species (ROS) and protein kinase C (PKC) activation are involved in NF-kappaB activation in mesangial cells (MC), and the role of NF-kappaB activation in HG-induced monocyte chemoattractant protein-1 (MCP-1) expression by MC was further investigated. Recent observations suggest that MCP-1 may play a role in the development and progression of diabetic nephropathy. HG rapidly induced NF-kappaB activation in MC as estimated by electrophoretic mobility shift assay. Supershift assay suggests that most of the binding activity arose from p50/p50 and p50/p65 dimers. Antioxidants, pyrrolidine dithiocarbamate, N-acetyl-L-cystein, and trolox effectively inhibited HG-induced NF-kappaB activation in MC. HG rapidly generated dichlorofluorescin-sensitive intracellular ROS in MC as measured by laser-scanning confocal microscopy. HG also activated PKC rapidly in MC. Inhibition of PKC effectively blocked HG-induced intracellular ROS generation and NF-kappaB activation in MC. HG increased MCP-1 mRNA expression by 1.9-fold and protein secretion by 1.6-fold that of control glucose in MC transfected with control vector but not in MC transfected with dominant negative mutant inhibitor of NF-kappaB (IkappaBalphaM). Inhibition of either PKC or ROS effectively blocked HG-induced, but not basal, MCP-1 protein secretion by MC transfected with control vector. Thus this study demonstrates that HG rapidly activates NF-kappaB in MC through PKC and ROS and suggests that HG-induced NF-kappaB activation in MC may play a role in diabetic renal injury through upregulation of MCP-1 mRNA and protein expression.     

An update on cyclooxygenase-2 expression and metabolites in the kidney

PURPOSE OF REVIEW: This review highlights recent studies examining the expression and function of cyclooxygenase-2 and its metabolites in the kidney. RECENT FINDINGS: Expression of cyclooxygenase-2 is regulated by both physiologic and pathophysiologic perturbations, with volume depletion upregulating macula-densa expression and volume expansion upregulating medullary expression. Macula densa cyclooxygenase-2 is a modulator of juxtaglomerular renin expression, and there is increasing evidence that cyclooxygenase-2 expression is modulated by multiple components of the renin-angiotensin system, including angiotensin II, through both AT1 and AT2 receptors. There are also indications that macula densa cyclooxygenase-2 expression may be regulated by the prorenin/renin receptor. Medullary cyclooxygenase-2 metabolites modulate salt and water excretion, and cyclooxygenase-2 inhibitors lead to sodium and volume retention and may raise blood pressure. There is also increasing evidence that cyclooxygenase-2 expression increases in progressive renal injury. Given their cardiovascular and renal side effects, cyclooxygenase-2 inhibitors are not a feasible intervention for long-term therapy against progressive renal damage, but further delineation of the downstream receptors and synthases involved may provide therapeutic targets. SUMMARY: Recent studies have highlighted the important role that cyclooxygenase-2 metabolites play both in regulation of normal renal function and as potential mediators of acute and chronic renal injury.     

Ovariectomy enhances renal cortical expression and function of cyclooxygenase-2

BACKGROUND: Cyclooxygenase-2 (COX-2) inhibitors are used as analgesics in postmenopausal women, who develop edema and require a salt-restricted diet. This study was performed to determine the renal expression of COX-2 and on COX-2-dependent regulation of renal blood flow (RBF) in ovariectomized rats. METHODS: Sprague-Dawley rats were divided into 4 groups: sham-operated rats fed a normal-salt diet (Sh+NS) or a low-salt diet (Sh+LS), and bilaterally ovariectomized rats fed a normal-salt diet (Ox+NS) or a low-salt diet (Ox+LS) (N= 6 in each group). Estrogen replacement therapy was performed on other ovariectomized rats. A renal clearance study was performed in anesthetized animals. RESULTS: Ovariectomy increased renal cortical COX-2 expression independently of dietary salt intake (Sh+NS 相似文献   

The relationship between angiogenesis and cyclooxygenase-2 expression in prostate cancer

OBJECTIVE: To test the hypothesis that angiogenesis in prostate cancer is associated with tumour invasion and metastasis, and that this is mediated through increased cyclooxygenase-2 (COX-2) expression. PATIENTS AND METHODS: Angiogenesis was assessed in 105 patients with either prostate cancer (79) or benign prostatic hyperplasia (BPH, 26) and these data correlated with levels of COX-2 expression in the same dataset. The mean microvessel density (MVD) was analysed as a marker of angiogenesis, using the endothelial antigen CD34 stained by immunohistochemistry. RESULTS: There was no difference in MVD in progressive tumour stages compared with BPH. There was a negative correlation between MVD and COX-2 expression, but the effect of increased COX-2 expression on MVD was not marked. CONCLUSION: These data suggest that COX-2 drives tumour spread in prostate cancer by means other than the promotion of angiogenesis.     

Sirolimus upregulates aP2 expression in human monocytes and macrophages

Rapamycin (Sirolimus) is a potent immunosuppressive drug that reduces renal transplant rejection. Hyperlipidemia is a significant side effect of rapamycin treatment, and frequently leads to cardiovascular disease. Adipocyte fatty acid binding protein (aP2) is a member of the cytoplasmic fatty acid binding protein (FABP) family. aP2 has been shown to affect insulin sensitivity, lipid metabolism, lipolysis, and has recently been shown to play an important role in atherosclerosis. We found that aP2 messenger RNA (mRNA) was increased in human THP-1 cells after rapamycin treatment. Exposure of human differentiated THP-1 cells to rapamycin led to a time- and dose-dependent induction of aP2 mRNA expression. While aP2 expression was undetectable in undifferentiated THP-1 cells, aP2 was induced in these cells by rapamycin. These data suggest that rapamycin-induced aP2 may play a role in increased triglyceride accumulation.     

Increased expression of cyclooxygenase-2 and nitric oxide synthase-2 in human prostate cancer

Cyclooxygenase-1 (COX-1), cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase-2 (NOS-2) each have an important role in angiogenesis. The expression of these genes was investigated in human prostate cancer by immunohistochemistry, the expression of COX-1 and COX-2 being confirmed by mRNA analysis. Prostate cancer specimens from 12 patients were compared to control prostates from 13 patients operated on for bladder carcinoma. The intensity of COX-2 and NOS-2 immunostaining was significantly stronger in prostate cancer cells than in the non-malignant glandular epithelium of the control prostates. COX-2 and NOS-2 were clearly also expressed in the lesions of prostatic intraepithelial neoplasia (PIN) in control prostates. COX-2 was detected in the muscle fibres of the hyperplastic stroma of some control prostates. No significant difference was detected in COX-1 expression between control and cancer prostates. These results indicate that the expression of COX-2 and NOS-2 is elevated in prostatic adenocarcinoma and in PIN. Received: 18 April 2000 / Accepted: 11 September 2000     

甲基强的松龙对大鼠脊髓损伤后环氧化酶-2表达的影响

目的：观察甲基强的松龙（MP）对正常及损伤脊髓组织中环氧化酶-2（COX-2）表达的影响。方法：216只Sprague-Dawlev大鼠．随机分为正常大鼠生理盐水处理组、正常大鼠MP处理组、生理盐水预处理脊髓损伤组、MP预处理脊髓损伤组、生理盐水治疗脊髓损伤组、MP治疗脊髓损伤组6组，每组又分为处理后2h、4h、8h、16h、24h、48h6个时间点；采用改良Allen’s打击法制作脊髓损伤动物模型，应用免疫组织化学染色的方法观察脊髓中COX-2蛋白表达的变化。结果：正常脊髓MP处理组16h后COX-2免疫组化染色程度明显降低，48h后仅灰质后角内有个别较小直径神经元显示微弱阳性染色；脊髓损伤后MP治疗组4h开始出现COX-2染色程度增高，并在损伤后48h达到最强程度的染色。但染色程度比生理盐水治疗组最强染色程度弱；MP预处理脊髓损伤组8h开始出现COX-2免疫组化染色程度的增高，并一直持续到损伤后48h，损伤后48h组染色程度比生理盐水预处理组最强染色程度弱、比脊髓损伤后MP治疗组染色程度弱。结论：MP能显著抑制正常和损伤脊髓组织中COX-2蛋白的表达，延迟其在损伤脊髓中的表达高峰时间，但不影响COX-2表达在空间上的分布。MP预处理比MP治疗能更显著地抑制损伤脊髓组织中COX-2蛋白的表达。     

p38 MAP kinase mediates endotoxin-induced expression of cyclooxygenase-2 in enterocytes

BACKGROUND: Necrotizing enterocolitis (NEC) occurs only after bacterial colonization of the intestine, suggesting that bacterial products, including lipopolysaccharide (endotoxin,) interact with enterocytes in the pathogenesis of this disease. Inflammatory molecules such as cyclooxygenase-2 (COX-2) are important mediators of the septic response leading to NEC. We therefore hypothesized that endotoxin activates production of COX-2 in enterocytes and explored the relative contributions of known mitogen-activated protein kinases (MAPK) pathways in this process. METHODS: IEC-6 enterocytes were treated with 5 microg/mL endotoxin, or various stresses, or media alone, and COX-2 protein levels were assayed by immunoblots with anti-COX-2 antibodies. Activation of MAPK was examined by immunoblots with phospho-MAPK antibodies. MAPK activity was blocked by treatment with pharmacologic inhibitors or transfection with dominant-negative MAPK constructs. RESULTS: Endotoxin treatment caused increased expression of the COX-2 protein 24 hours after treatment. This was preceded by rapid and transient activation of the 3 major MAPKs: extracellular-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and p38. SB203580, a specific inhibitor of p38, but not U0126 (ERK inhibitor) or SP600125 (JNK inhibitor), blocked endotoxin-induced accumulation of COX-2 protein. This response was also blocked by expression of dominant-negative p38 but not by the dominant-negative ERK construct. Genotoxic stress that activated p38 but not ERK was an effective inducer of COX-2, whereas stresses that activated both p38 and ERK were not effective. ERK inhibition by U1026 enhanced endotoxin-induced production of COX-2, consistent with negative regulation of COX-2 by ERK. These data point to p38 as the MAPK that mediates endotoxin-induced production of COX-2 in enterocytes. CONCLUSIONS: Endotoxin may be capable of inducing the production of COX-2 in enterocytes via the p38 MAPK pathway, which may be relevant to the development of NEC.     

Hyaluronan-induced cyclooxygenase-2 expression promotes thromboxane A2 production by renal cells

BACKGROUND: Matrix degradation products such as fragmented hyaluronan (HA) display important proinflammatory effects on renal tubular epithelial cells (TECs) and macrophages (MPhis). We hypothesized that HA could up-regulate cyclooxygenase type 2 (COX-2) in these cells and that the subsequent production of thromboxane A2 (TXA2) could play a role in inflammatory renal lesions. METHODS: We used an in vitro approach to examine the expression of COX-1 and COX-2 and the production of TXA2 in response to fragments of HA. COX-2 mRNA, protein, and the resulting TXA2 production were measured in CD44-positive, HA-responsive cells lines of TECs and MPhi. COX-2 mRNA was also measured in vivo in MRL-Faslpr mice and in mice with anti-glomerular basement membrane (anti-GBM) nephritis. RESULTS: In TECs and MPhis, HA increased the steady-state COX-2 mRNA and protein levels markedly, whereas COX-1 mRNA levels did not change. The HA-induced response was comparable to lipopolysaccharide stimulation. In comparison with MPhi, the response was much weaker in TECs. Likewise, the production of TXA2 in response to HA was markedly increased in MPhi, but less in TECs. In TECs and in MPhi, the HA-stimulated TXA2 synthesis was inhibited with the COX-2-selective inhibitors SC58125 (12.5 micromol/L) or celecoxib (0.25 to 5.00 micromol/L). COX-2 mRNA levels were increased in nephritic mice with MRL-Faslpr lupus nephritis and in mice with anti-GBM disease. CONCLUSIONS: HA is a proinflammatory factor that stimulates COX-2 expression and subsequent TXA2 production. Since HA accumulates markedly in renal injury, we speculate that this matrix molecule could therefore play a significant role in thromboxane-mediated immune events in the kidney.     

己酮可可碱对高糖诱导肾小球系膜细胞结缔组织生长因子表达信号通路的影响

目的 探讨高糖诱导大鼠肾小球系膜细胞结缔组织生长因子（CTGF）表达的变化及其作用通路,并且研究己酮可可碱（PTX）对CTGF表达的影响。 方法 体外培养大鼠系膜细胞,观察不同浓度的高糖在不同时间对系膜细胞转化生长因子β（TGF-β）、CTGF、 p-Smad2/3、Smad7及纤连蛋白（FN）表达的影响;并在高糖培养液中加入TGF-β中和抗体及不同浓度的PTX观察其对上述各指标表达的影响。 结果 高糖可以诱导系膜细胞TGF-β、CTGF mRNA及蛋白表达增加（均P < 0.05）,且呈时间、剂量依赖性,同时伴有p-Smad2/3蛋白表达的增加及Smad7蛋白表达的减少。阻断TGF-β可使高糖诱导的CTGF mRNA及蛋白表达分别下降86.4%及91.8%（均P < 0.05）。PTX可以抑制高糖诱导的系膜细胞CTGF mRNA及蛋白表达,随着PTX浓度的增加其抑制作用更为显著（P < 0.05）,但对于TGF-β的表达没有影响。结论 高糖可通过TGF-β-Smads通路使CTGF mRNA表达增加进而影响其蛋白表达。PTX可以有效的抑制CTGF的表达而对于TGF-β的表达没有直接的抑制作用。     

环氧化酶-2在胃癌组织中的表达及其与血管生成的关系

目的探讨环氧化酶-2(COX-2)在胃癌组织中的表达及其与肿瘤血管生成的关系。方法应用免疫组织化学(免疫组化)法检测96例胃癌手术切除标本中COX-2的表达,采用抗CD34抗体标记微血管内皮细胞,计算微血管密度(MVD)。分析COX-2表达与MVD和胃癌主要临床病理特征的相关性。结果胃癌组织COX-2阳性表达率和MVD分别为80.2%和32.5±8.3,显著高于正常胃黏膜的13.3%和13.1±2.4;P<0.01。临床TNM分期中Ⅲ、Ⅳ期胃癌标本COX-2表达率与MVD为91.4%和34.9±8.7,显著高于Ⅰ和Ⅱ期胃癌标本(P<0.01)。伴有淋巴结转移的胃癌组织中COX-2表达率和MVD分别为87.9%和35.0±8.5,与无淋巴结转移病例相比,差异有统计学意义(P<0.05)。Spearman等级相关分析表明,COX-2表达与MVD呈显著正相关(γ=0.311,P<0.01)。结论COX-2表达在胃癌的肿瘤血管生成中起重要作用,COX-2及其诱导的血管生成与胃癌的浸润和转移密切相关。     

雄激素调控大鼠阴茎海绵体组织中eNOS表达的分子机制

目的:研究雄激素是否通过蛋白激酶B-3(AKT3)、Ⅰ类磷脂酰肌醇-3-激酶的p110催化亚单位(PIK3CA)、钙调蛋白(CALM)、小窝蛋白1(CAV1)调控大鼠阴茎海绵体组织内皮型一氧化氮合酶(e NOS)的表达,并影响阴茎勃起功能。方法:8周龄健康雄性SD大鼠36只,随机均分为6组:4周对照组(A组)、6周对照组(B组)、4周去势组(C组)、6周去势组(D组)、4周去势+睾酮(T)替代组(E组)、6周去势+T替代组(F组)。C、D、E、F组切除双侧睾丸及附睾,1 d后E、F组隔日1次丙酸睾酮3 mg/kg皮下注射,其余各组等量植物油皮下注射。4周后(A、C、E组)、6周后(B、D、F组)分别检测各组大鼠海绵体内压(ICP_(max))/平均动脉压(MAP)、血清T,通过免疫组化法及Western印迹法分别测定e NOS、P-e NOS、AKT3、PIK3CA、CALM、CAV1在各组大鼠阴茎海绵体中的表达。结果:各组实验大鼠体重、MAP无显著差异。血清T值和ICP_(max)/MAP比值:去势组(C、D组)较对照组(A、B组)及去势+T替代组(E、F组)极显著降低(P均0.01),且去势6周组(D组)较去势4周组(C组)显著降低(P均0.05),去势+T替代组(E、F组)及对照组(A、B组)各组间无显著差异。免疫组化结果显示:e NOS、Pe NOS主要表达在血管内皮细胞胞膜和海绵窦血管腔内;AKT3、PIK3CA、CALM、CAV1主要表达于血管内皮细胞胞质和胞膜,少数表达于平滑肌细胞。e NOS、P-e NOS、AKT3、PIK3CA、CALM、CAV1Western印迹结果显示:去势组(C、D组)与对照组(A、B组)、去势+T替代组(E、F组)相比极显著降低(P均0.01),去势+T替代组(E、F组)与对照组(A、B组)相比无显著差异,且6周去势组(D组)比4周去势组(C组)表达显著降低(P均0.05),6周去势+T替代组(F组)与4周去势+T替代组(E组)相比无显著差异,6周对照组(B组)与4周对照组(A组)相比无显著差异。结论:雄激素可能通过上调AKT3、PIK3CA、CALM、CAV1蛋白的表达,磷酸化e NOS后激活e NOS,促进勃起;然而,确切的机制还应该采用AKT3、PIK3CA、CALM、CAV1等的阻滞剂或者激活剂,以及采用基因转染或者基因敲除等方法,进一步明确分子机制。