Reactivation of mutant p53 in esophageal squamous cell carcinoma by isothiocyanate inhibits tumor growth.

p53 mutations are prevalent in human cancers; approximately half of patients with esophageal cancer present these mutations. Mutant p53 (mutp53) exerts oncogenic functions that promote malignant tumor progression, invasion, metastasis, and drug resistance, resulting in poor prognosis. Some small molecules have been shown to mitigate the oncogenic function of mutp53 by restoring its wild-type activity. Although these molecules have been evaluated in clinical trials, none have been successfully used in the clinic. Here, we investigated the antitumor effects of phenethyl isothiocyanate (PEITC) in p53-mutant esophageal squamous cell carcinoma (ESCC) and elucidated its mechanism to identify new therapeutic strategies. We observed that p53R248Q is a DNA contact mutation and a structural mutation and that PEITC can restore the activity of p53R248Q in vitro and in vivo, further clarifying the antitumor activity of PEITC in cancers with different types of p53 mutations. PEITC can inhibit ESCC growth, induce apoptosis, and arrest cell cycle progression and has a preferential selectivity for ESCC with p53 mutations. Mechanistic studies showed that PEITC induced apoptosis and arrested cells at G2/M transition in cells expressing the p53R248Q mutant by restoring the wild-type conformation and transactivation function of p53; these effects were concentration dependent. Furthermore, PEITC inhibited the growth of subcutaneous xenografts in vivo and restored p53 mutant activity in xenografts. According to these findings, PEITC has antitumor effects, with its ability to restore p53R248Q activity being a key molecular event responsible for these effects.

Apatinib inhibits tumour progression and promotes antitumour efficacy of cytotoxic drugs in oesophageal squamous cell carcinoma.

Apatinib, a highly selective inhibitor of vascular endothelial growth factor receptor-2 (VEGFR-2), inhibits the angiogenesis of tumours. The function and mechanism of apatinib in oesophageal squamous cell carcinoma (ESCC) remain unknown. In present study, we found that the development of ESCC in patients was controlled by treatment of combination of apatinib and a chemotherapeutic drug. Moreover, apatinib efficiently promotes cell apoptosis, inhibits cell proliferation, invasion, epithelial-mesenchymal transition (EMT) and activity of the Akt/mTOR pathway in ESCC cells. Western blot analysis showed that apatinib significantly increased vimentin protein levels, decreased Bcl2, matrix metalloproteinase 9 (MMP9), E-cadherin, p-Akt and p-mTOR protein levels in ESCC cells. Furthermore, apatinib enhanced chemosensitivity of cytotoxic drugs paclitaxel (TAX), 5-fluorouracil (5-FU) and cisplatin (DDP) by upregulating expression of vimentin protein, and downregulating expression of Bcl2, MMP9 and E-cadherin protein in vitro. Compared with single-agent groups, the combination of apatinib with each chemotherapeutic drug significantly repressed tumour growth and angiogenesis through blocking the expression of Ki67 and VEGFR-2 in vivo. Taken together, apatinib efficiently inhibits cell growth through blocking Bcl2 and Akt/mTOR pathway, and suppresses metastasis via inhibiting MMP9 and EMT in ESCC cells. Apatinib promoted antitumour effect of chemotherapeutic agents through promoting cell apoptosis and inhibiting EMT and angiogenesis in ESCC.

miR-516a-3p inhibits breast cancer cell growth and EMT by blocking the Pygo2/Wnt signalling pathway.

miR-516a-3p has been reported to play a suppressive role in several types of human tumours. However, the expression level, biological function and fundamental mechanisms of miR-516a-3p in breast cancer remain unclear. In the present study, we found that miR-516a-3p expression was down-regulated and Pygopus2 (Pygo2) expression was up-regulated in human breast cancer tissues and cells. Through analysing the clinicopathological characteristics, we demonstrated that low miR-516a-3p expression or positive Pygo2 expression was a predictor of poor prognosis for patients with breast cancer. The results of a dual luciferase reporter assay and Western blot analysis indicated that Pygo2 was a target gene of miR-516a-3p. Moreover, overexpression of miR-516a-3p inhibited cell growth, migration and invasion as well as epithelial-mesenchymal transition (EMT) of breast cancer cells, whereas reduced miR-516a-3p expression promoted breast cancer cell growth, migration, invasion and EMT. Furthermore, we showed that miR-516a-3p suppressed cell proliferation, metastasis and EMT of breast cancer cells by inhibiting Pygo2 expression. We confirmed that miR-516a-3p exerted an anti-tumour effect by inhibiting the activation of the Wnt/ß-catenin pathway. Finally, xenograft tumour models were used to show that miR-516a-3p inhibited breast cancer cell growth and EMT via suppressing the Pygo2/Wnt signalling pathway. Taken together, these results show that miR-516a-3p inhibits breast cancer cell growth, metastasis and EMT by blocking the Pygo2/ Wnt/ß-catenin pathway.

Sevoflurane prevents miR-181a-induced cerebral ischemia/reperfusion injury.

BACKGROUND: Sevoflurane (sevo) has been reported to be an effective neuroprotective agent in cerebral ischemia/reperfusion injury (CIRI). However, the precise molecular mechanism underlying sevo preconditioning in CIRI remains largely unknown. METHODS: A middle cerebral artery occlusion (MCAO) rat model and primary cortical neurons after oxygen-glucose deprivation and reoxygenation (OGDR) were used as the in vivo and in vitro models of CIRI. The expression profiles of miR-181a and X chromosome-linked inhibitor-of-apoptosis protein (XIAP) in the cerebral cortex of rats and in cortical neurons were examined by qRT-PCR and Western blot, respectively. The infarct volumes were measured by TTC staining and neurological deficits in rats was determined by Zea-Longa scoring criteria. The cell viability, lactate dehydrogenase (LDH) release and apoptotic rate were detected in cortical neurons by MTT assay, LDH analysis and flow cytometry. Western blot analysis was performed to assess the expression of apoptosis-related protein. Luciferase reporter assay was used to confirm the interaction between miR-181a and XIAP. RESULTS: miR-181a was upregulated and XIAP was downregulated in rats after MCAO. Sevo preconditioning attenuated miR-181a expression and promoted XIAP level in a rat model of CIRI. Sevo preconditioning ameliorated anti-miR-181a-mediated protective effects on cerebral ischemia in rat model of CIRI, presented as the decrease of infarct volume, neurological deficit and apoptosis. Moreover, sevo pretreatment abated miR-181a-induced cellular injury in primary cortical neurons after OGD, embodied by the increase of cell viability, the reduction of LDH release and the decline of apoptosis. Furthermore, miR-181a suppressed XIAP expression by binding to its 3'UTR in cortical neurons, and sevo-mediated increase on XIAP expression was counteracted by miR-181 overexpression in OGDR-treated neurons. CONCLUSION: Sevo preconditioning protected against CIRI in vitro and in vivo possibly by inhibiting miR-181a and facilitating XIAP.

ZKSCAN3 promotes breast cancer cell proliferation, migration and invasion.

ZKSCAN3, a zinc-finger transcription factor, which has been shown to be upregulated in several human cancer. However, the expression level, function and mechanism of ZKSCAN3 in breast cancer remains unknown. In the current study, immunohistochemistry, western blot and quantitative real time polymerase chain reaction (qRT-PCR) results showed that ZKSCAN3 was overexpressed in breast cancer tissue compared with normal breast tissue. Through analyzing the clinicopathological characteristics, we demonstrated that positive ZKSCAN3 expression predicted poor prognosis of patients with breast cancer. The expression level of ZKSCAN3 protein/mRNA in breast cancer cells (MCF-7 and MDA-MB-231) was higher than its expression in normal breast cells (HBL-100). Knocking down ZKSCAN3 via its short hairpin RNA (shRNA) in MCF-7 and MDA-MB-231 inhibited cell viability, migration and invasion. Western blot analysis showed that ZKSCAN3 silencing lead to significant decreases in the expression of Cyclin D1, B-cell lymphoma-2 (Bcl-2), and matrix metalloproteinase (MMP)-2/MMP-9, as well as increases in the expression of Bcl2 Associated X Protein (Bax) in breast cancer cells. Additionally, ZKSCAN3-shRNA expression markedly suppressed tumor growth in breast cancer xenograft mice. Finally, we demonstrated that silencing of ZKSCAN3 was able to inhibit Akt/mTOR signaling pathway by blocking p-Akt and p-mTOR protein expression in breast cancer cells. These results demonstrate that ZKSCAN3 plays a significant role in the progression of breast cancer. Therefore, ZKSCAN3 is a potential therapeutic target for breast cancer.

miR-106b promotes cell invasion and metastasis via PTEN mediated EMT in ESCC.

MicroRNA (miR)-106b serves an essential function in a variety of human cancer types, particularly in the process of invasion and metastasis. However, the function and mechanism of miR-106b in the invasion and metastasis of esophageal squamous cell carcinoma (ESCC) has remained elusive. In the present study, it was demonstrated that miR-106b was upregulated in ESCC tissues and cell lines. Furthermore, miR-106b expression in ESCC tissues was positively associated with lymphatic metastasis. Inhibition of miR-106b in EC-1 and EC9706 cells decreased not only the invasion and metastasis ability but also the proliferation ability of EC-1 and EC9706 cells. In addition, miR-106b had the ability to induce epithelial-to-mesenchymal transition (EMT) in EC-1 and EC9706 cells. In terms of the underlying mechanism, it was revealed that miR-106b promoted the invasion, metastasis and proliferation ability of EC-1 and EC9706 cells by directly targeting phosphatase and tension homolog (PTEN). Furthermore, miR-106b induced EMT in EC-1 and EC9706 cells by suppressing the expression of PTEN. In summary, the present study revealed that miR-106b contributed to invasion and metastasis in ESCC by regulating PTEN mediated EMT. Downregulation of miR-106b may be a novel strategy for preventing tumor invasion and metastasis.

Expression of P-EGFR and P-Akt protein in esophageal squamous cell carcinoma and its prognosis.

The phosphorylated epidermal growth factor receptor (P-EGFR) and phosphorylated Akt (P-Akt) protein in esophageal squamous cell carcinoma (ESCC) were studied, and its significance in clinical prognosis of patients was assessed. The expression of P-EGFR and P-Akt protein in 83 cases of ESCC and 83 normal esophageal tissues was determined by immunohistochemical staining. Log-rank test and correlation analysis were used to analyze the prognosis of ESCC. The positive expression of P-EGFR in ESCC was 88% (73/83 cases) compared with 41% in normal esophageal mucosa (34/83 cases) (P<0.05). The rate of P-Akt protein expression in ESCC was 90.4% (75/83 cases), compared with 27.7% seen in normal esophageal mucosa (23/83 cases) (P<0.05). The expression of P-EGFR and P-Akt protein was positively correlated with lymph node metastasis and degree of differentiation (P<0.05) irrespective of sex, age, tumor diameter and TNM stage (P>0.05). The expression of P-EGFR was positively correlated with that of P-Akt protein (r=0.674, P<0.01). P-EGFR expression was negatively correlated with survival time of patients with ESCC (r=-0.526, P<0.01). The Kaplan-Meier survival curves showed that the cumulative survival rate of P-EGFR-positive cases was significantly lower than that of the P-EGFR-negative cases (P<0.01). The expression of P-Akt was negatively correlated with survival in patients with ESCC (r=-0.473, P<0.01). The Kaplan-Meier survival curves showed that the cumulative survival rate of the P-Akt-positive cases was significantly lower than that of the P-Akt-negative cases (P<0.01). In conclusion, P-EGFR and P-Akt protein expression is closely related to the incidence of ESCC and mediates the development of invasive cancer and metastasis. It is used to determine the prognosis of ESCC, and may represent a new therapeutic target for the disease.

Metformin inhibited esophageal squamous cell carcinoma proliferation in vitro and in vivo and enhanced the anti-cancer effect of cisplatin.

Esophageal squamous cell carcinoma (ESCC) is an aggressive malignancy with poor prognosis in China. Chemotherapy now is one of the most frequently used treatments for patients with ESCC in middle or late stage, however the effects were often limited by increased chemoresistance or treatment toxicity. So it is urgent to find new drugs to treat ESCC patients. Metformin with low cost and toxicity has proved to have anti-cancer effects in a numerous cancers, while its role and mechanism in ESCC has seldom been studied. In the present study, we found that metformin exhibited not only an anti-proliferation ability in a dose and time dependent manner but also a proapoptosis effect in a dose dependent manner in ESCC cell line KYSE450. Our in vivo experiment also showed that metformin markedly inhibited KYSE450 xenograft tumors growth compared to those treated with normal saline. What's more, no obvious toxic reactions were observed. To further explore the underlying mechanism, we found that metformin treatment could significantly damp the expression of 4EBP1 and S6K1 in KYSE 450 cells in vitro and in vivo, furthermore, the p-4EBP1 and p-S6K1 expression in KYSE 450 cells were also inhibited greatly in vitro and in vivo. During the therapy of cancer, in order to overcome side effects, combination therapy was often used. In this paper, we demonstrated that metformin potentiated the effects of cisplatin via inhibiting cell proliferation and promoting cell apoptosis. Taken together, metformin owned the potential anti-cancer effect on ESCC in monotherapy or was combined with cisplatin and these results laid solid basis for the use of metformin in ESCC.

P-mTOR Expression and Implication in Breast Carcinoma: A Systematic Review and Meta-Analysis.

OBJECTIVE: Phosphorylated mammalian target of rapamycin (p-mTOR) is a promising prognostic marker in many types of cancer. However, its survival benefit in patients with breast carcinoma remains unknown. The aim of the present study was to assess the relationship between p-mTOR expression and prognosis in breast carcinoma based on a systematic review and meta-analysis. MATERIALS AND METHODS: Electronic databases (including Pubmed, Embase, ISI web of science, and Cochrane Library) were searched up to November 24, 2015. The outcome measures were hazard ratios (HRs) with 95% confidence interval (CI) for the association between the prognosis of breast carcinoma patients and p-mTOR expression. Primary end points were disease-free survival (DFS), overall survival (OS), and recurrence-free survival (RFS). Statistical analysis was performed with STATA 12.0. RESULTS: Nine cohort studies including 3051 patients met full eligibility criteria. The pooled HRs (95% CI) for OS, DFS, and RFS were 0.84 (0.27-2.63), 0.71 (0.40-1.23), and 0.48 (0.20-1.18), respectively. CONCLUSIONS: Our findings suggested that p-mTOR overexpression was not significantly related to prognosis in breast carcinoma regarding OS and disease recurrence. Prospective studies are warranted to examine the association between p-mTOR expression and survival outcomes in breast carcinoma.

NFAT1 promotes cell motility through MMP-3 in esophageal squamous cell carcinoma.

Esophageal squamous cell carcinoma (ESCC) is one of the most common malignant tumors and the prognosis of patients remains poor. Increasing evidence suggests that nuclear factor of activated T cell (NFAT1) plays an important role in the development and progression of cancers. Herein, we show that NFAT1 was overexpressed in human ESCC, which was significantly associated with advanced tumor stage and lymph node metastasis. Functional studies found that NFAT1 silencing could suppress cell migration and invasion through MMP-3. The data therefore suggest that NFAT1 plays an important adverse role in the development and progression of ESCC, implicating possible application in clinics as a biomarker and a potential new therapeutic target.

N-cadherin participated in invasion and metastasis of human esophageal squamous cell carcinoma via taking part in the formation of vasculogenic mimicry.

Vasculogenic mimicry (VM) refers to the unique ability of highly aggressive tumor cells to mimic the pattern of embryonic vasculogenic networks, and the presence of VM correlates to an increased risk of metastasis and poor clinical outcome of cancers. Several key molecules, including N-cadherin, have been implicated in VM. However, the role of N-cadherin in the formation of VM in esophageal squamous cell carcinoma (ESCC) had not been elucidated. In this study, firstly we aimed to identify VM patterns in ESCC tissues and to explore their clinical significance. VM was present in 12 out of 56 samples, and ESCC with lymph node metastasis had a higher incidence of VM than that without lymph node metastasis. More importantly, VM channels were associated with the expression of N-cadherin in ESCC tissues. In order to further explore the role of N-cadherin in VM formation and invasion and metastasis in ESCC, secondly, we silenced the expression of N-cadherin with small hairpin RNA in ESCC cell line KYSE-70; herein, we showed that KYSE-70 cells with N-cadherin silencing lost not only the capacity to form tube-like structures on collagen (VM) but also the invasion, metastasis and proliferation ability in KYSE-70 cells in vitro. Taken together, antivascular therapies targeting tumor cell VM may be an effective approach to the treatment of patients with highly metastatic ESCC.

[Enhanced expression of caveolin-1 in articular chondrocytes in osteoarthritis].

OBJECTIVE: To study the expression level of caveolin-1 in articular chondrocytes in patients with osteoarthritis (OA), and whether catabolic factor IL-1beta stimulate caveolin-1 expression in articular chondrocytes. METHODS: In human OA cartilage, caveolin-1 mRNA was investigated by quantitative real-time RT-PCR while caveolin-1 protein was detected by immunohistologic analysis in 8 cases. OA model was prepared by unilateral anterior cruciate ligament and medial collateral ligament transection in 20 rats. In cultured OA chondrocytes, caveolin-1 mRNA expression was studied by RT-PCR and quantitative real-time RT-PCR, and caveolin-1 protein was analyzed by Western blotting. RESULTS: In 6 of 8 OA cases, human OA articular cartilage, higher expression levels of both caveolin-1 mRNA and caveolin-1 protein were found in advanced degenerated cartilage than less degenerated cartilage of the same joints. In rat OA model, upregulated caveolin-1 expression was found, which was associated with the degree of cartilage destruction. IL-1beta (10 ng/ml) upregulated caveolin-1 mRNA/protein expression in cultured OA chondrocytes for at least 48 hours. CONCLUSION: Enhanced expression level of caveolin-1 is associated with cartilage degeneration in OA. IL-1beta stimulates caveolin-1 expression in articular chondrocytes, which may be responsible for OA development.

Cellular targets of interleukin-18 in rheumatoid arthritis.

Recent data are presented which indicate a critical role for interleukin (IL)-18 in rheumatoid arthritis (RA). The T cells and macrophages invading the synovium or in the synovial fluid are the chief cellular targets of IL-18 in RA. Neutrophils, dendritic cells and endothelial cells may also be cellular mediators of IL-18. The direct effect of IL-18 on fibroblast-like synoviocytes or chondrocytes may not be essential or important. In RA, IL-18, which is mainly produced by macrophages, activates T cells and macrophages to produce proinflammatory cytokines, chemokines, adhesion molecules and RANKL which, in turn, perpetuate chronic inflammation and induce bone and cartilage destruction.

Catabolic stress induces features of chondrocyte senescence through overexpression of caveolin 1: possible involvement of caveolin 1-induced down-regulation of articular chondrocytes in the pathogenesis of osteoarthritis.

OBJECTIVE: Articular chondrocyte senescence is responsible, at least in part, for the increased incidence of osteoarthritis (OA) with increased age. Recently, it was suggested that caveolin 1, a 21-24-kd membrane protein, participates in premature cellular senescence. Caveolin 1 is the principal structural component of caveolae, vesicular invaginations of the plasma membrane. This study was undertaken to investigate whether the catabolic factors oxidative stress and interleukin-1beta (IL-1beta) induce features of premature senescence of articular chondrocytes through up-regulation of caveolin 1 expression. METHODS: Caveolin 1 expression was investigated in human OA cartilage by real-time polymerase chain reaction and in rat OA cartilage by immunohistologic analysis. We studied whether IL-1beta and H2O2 induce caveolin 1 expression in OA chondrocytes and analyzed the relationship between cellular senescent phenotypes and caveolin 1 expression in human chondrocytes. RESULTS: In human and rat OA articular cartilage, caveolin 1 positivity was associated with cartilage degeneration. Both IL-1beta and H2O2 up-regulated caveolin 1 messenger RNA and protein levels, and both treatments induced marked expression of senescent phenotypes: altered cellular morphology, cell growth arrest, telomere erosion, and specific senescence-associated beta-galactosidase activity. Caveolin 1 overexpression induced p38 MAPK activation and impaired the ability of chondrocytes to produce type II collagen and aggrecan. In contrast, down-regulation of caveolin 1 with antisense oligonucleotide significantly inhibited the features of chondrocyte senescence induced by catabolic factors. Caveolin 1 induction and stresses with both IL-1beta and H2O2 up-regulated p53 and p21 and down-regulated phosphorylated retinoblastoma (Rb), suggesting that the p53/p21/Rb phosphorylation pathway, as well as prolonged p38 MAPK activation, may mediate the features of chondrocyte senescence induced by stress. CONCLUSION: Our findings suggest that IL-1beta and oxidative stress induce features of premature senescence in OA chondrocytes, mediated, at least in part, by stress-induced caveolin 1 expression. This indicates that caveolin 1 plays a role in the pathogenesis of OA via promotion of chondrocyte down-regulation.

A potential role of 15-deoxy-delta(12,14)-prostaglandin J2 for induction of human articular chondrocyte apoptosis in arthritis.

The cyclopentenone prostaglandin (PG) J2 is formed within the cyclopentenone ring of the endogenous prostaglandin PG D2 by a nonenzymatic reaction. The PG J family is involved in mediating various biological effects including the regulation of cell cycle progression and inflammatory responses. Here we demonstrate the potential role of 15-deoxy-Delta(12,14)-prostaglandin J2 (15d-PG J2) in human articular chondrocyte apoptosis. 15d-PG J2 was released by human articular chondrocytes and found in joint synovial fluids taken from osteoarthritis or rheumatoid arthritis patients. Proinflammatory cytokines such as interleukin-1beta (IL-1beta) and tumor necrosis factor-alpha (TNF-alpha) up-regulated chondrocyte release of 15d-PG J2. PG D2 synthase mRNA expression was up-regulated by IL-1beta, TNF-alpha, or nitric oxide. 15d-PG J2 induced apoptosis of chondrocytes from osteoarthritis or rheumatoid arthritis patients as well as control nonarthritic subjects in a time- and dose-dependent manner and in a peroxisome proliferator-activated receptor gamma-dependent manner. Peroxisome proliferator-activated receptor gamma expression was up-regulated by IL-1beta and TNF-alpha. Inhibition of NF-kappaB, and the activation of p38 MAPK were also found to be involved in 15d-PG J2-induced chondrocyte apoptosis. Such signal pathways led to the activation of the downstream pro-apoptotic molecule p53 and caspase cascades. Together, these results suggest that 15d-PGJ2 may play an important role in the pathogenesis of arthritic joint destruction via a regulation of chondrocyte apoptosis.

Changes of central norepinephrine, beta-endorphin, LEU-enkephalin, peripheral arginine-vasopressin, and angiotensin II levels in acute and chronic phases of sino-aortic denervation in rats.

We and others have demonstrated that impaired arterial baroreceptor reflex (ABR) function is one of the major causes of hypertension-associated end organ damage. The goal of this study was to clarify the potential neuro-humoral mechanisms responsible for impaired ABR-induced end organ damage. The sino-aortic denervated (SAD) rat was used as an animal model of ABR dysfunction. One-week SAD rats were characterized by hypertension, tachycardia, increased norepinephrine content, and decreased beta-endorphin and leu-enkephalin content in hypothalamus and medulla oblongata, and increased plasma levels of arginine-vasopressin. In 18-week SAD rats, the 24-hour average arterial pressure, heart rate, beta-endorphin, and leu-enkephalin content in hypothalamus and medulla oblongata and plasma levels of arginine-vasopressin and angiotensin II were not different from those measured in ABR-intact rats. However, blood pressure variability and angiotensin II content in kidney and left ventricle increased. When exposed to chronic stress, exaggerated changes in arterial pressure, blood pressure variability, the levels of central norepinephrine, beta-endorphin and leu-enkephalin, plasma arginine-vasopressin and angiotensin II, and tissue angiotensin II were found in 18-week SAD rats. These data indicate that a long-term impairment of ABR leads to chronic activation of central noradrenergic neurons and tissue renin-angiotensin system, and that stress induces exaggerated responses of neuro-humoral factors and hemodynamics in SAD rats. Thus, if the present results hold true for humans, one can expect abnormal neurotransmitter/neuromodulator responses to environmental insults in patients with impaired ABR function.

[Angiotensin II contents in plasma, and cardiac and renal tissues of sinoaortic denervated rats].

Our previous data demonstrate that impairment of arterial baroreceptor reflex (ABR) plays an independent role in hypertension target organ damage. To elucidate the mechanisms responsible for the dysfunction of ABR associated organ damage, sinoaortic denervated (SAD) rats were used as an animal model of ABR dysfunction. Twenty-four-hour continuous blood pressure (SBP and DBP), blood pressure variability (BPV), heart rate (HR) and HR variability (HRV) were measured in conscious and unrestrained rats. Angiotensin II (Ang II) in plasma, heart and kidney was assayed by raio-immunological assay (RIA) 1 or 18 weeks after denervation. In short-term SAD rats, twenty-four-hour mean SBP and DBP increased compared with that of sham-operated rats and long-term SAD rats. No significant difference in SBP, DBP or HR was found between long-term SAD rats and sham-operated ones. Compared with the sham-operated rats, long-term SAD rats had elevated BPV. No significant change in Ang II levels of caridiac and renal tissues was found in short-term SAD rats. In long-term SAD rats, Ang II level of plasma was not increased while the Ang II content in the heart and kidney increased. Ang II contents of plasma and tissues in long-term SAD rats exposed to chronic stress were higher than those in the control rats. These results show (1) in short-term SAD rats blood pressure increased, while in long-term SAD rats 24 h mean blood pressure did not increase, although BPV elevated in long-term SAD rats; (2) in long-term SAD rats, secretion of Ang II in cardiac and renal tissues was enhanced and more Ang II released when the animals were exposed to chronic stress. These results suggest that elevated BPV and secretion of Ang II may be related to the development of organ damage induced by ABR dysfunction.