AIM To investigate effect of Iosartan, an AT1 receptor antagonist, on hepatic fibrosis induced by CCI4; and to determine whether or not AT1 receptors are expressed on hepatic stellate cells. M~THODS AND RESULTS Fifty male SpragueDawley rats, weighing (180 ± 20) g, were randomized into five groups (control group, model group, and three Iosartan treated groups ), in which all rats were given the subcutaneous injection of 40% CCl4 (every 3 days for 6 weeks) except for rats of control group. Rats of Iosartantreated groups were treated with Iosartan (20 mg/ kg, 10 mg/kg, 5 mg/kg, daily gavage). After 6 weeks liver tissue and serum samples of all rats were examined. Serum hyaluronic acid (HA), procollagen type Ⅲ (PC Ⅲ ) were detected by radioimmunoassays. van Giesion collagen staining was used to evaluate the extracellular matrix of rats with liver fibrosis. The expression of AT1 receptors, transforming growth factor-beta (TGFβ), and alpha-smooth muscle actin (α-SMA) in liver tissue were determined by immunohistochemical techniques. Compared with model group, serum ALT and AST of Iosartantreated groups were significantly reduced (t = 4.20, P < 0.01 and t = 4.57, P < 0.01 ). Serum HA and PC Ⅲ also had significant differences (t = 3.53, P<0.01 and t=2.20, P<0.05). The degree of fibrosis was improved by Iosartan and correlated with the expressions of AT1 receptors, TGF-β, and α-SMA in liver tissue. CONCLUSION AT1 receptor antagonist, Iosartan, could limit the progression of the hepatic fibrosis induced by CCl4. The mechanism may be related to the decrease in the expression of AT1 receptors and TGF-β, ameliorating the injury of hepatocytes; activation of local renin-angiotensin system might relate to hepatic fibrosis; and during progression of fibrosis, activated hepatic stellate cells might express AT1 receptors.

Purpose　To review evidence-based management of nephropathy in patients with type 2 diabetes.Data sources　A literature search (MEDLINE 1966 to 2000) was performed using the key word “diabetic nephropathy". Relevant book chapters were also reviewed.Study selection　Well-controlled, prospective landmark studies and expert review articles on diabetic nephropathy were selected.Data extraction　Data and conclusions from the selected articles that provide solid evidence to the optimal management of diabetic nephropathy were extracted and interpreted in light of our clinical research experience with many thousands of Hong Kong Chinese patients.Results　Hypertension, long diabetes duration, poor glycaemic control and central obesity are the most important risk factors. Microalbuminuria is a practical marker to predict overt nephropathy in type 2 diabetic patients. Risk factor modification, renal function monitoring and combined therapies are the current integrated approaches to manage patients with diabetic kidney disease. Optimal glycaemic control is the mainstay of treatment but effective antihypertensive therapy is also key to delaying the progression of diabetic nephropathy. Angiotensin-converting enzyme inhibitors and angiotensin Ⅱ receptor antagonists have important renoprotective actions independent of their blood pressure lowering actions. Conclusions　Diabetic nephropathy is the leading cause of end-stage renal disease worldwide. Monitoring renal function and screening for microalbuminuria will allow the identification of patients with nephropathy at a very early stage for intervention. Tight glycaemic control and aggressive antihypertensive treatment as well as the use of renin-angiotensin system inhibitors should substantially delay the progression of nephropathy.

Objective:To investigate the expressions of AT1-R, AT2-R and angiotensin converting enzyme (ACE) in mesenchymal stem cells (MSCs) under hypoxia and serum deprivation condition. Methods:Bone MSCs were isolated, cultured and identiifed by anti-CD29 and anti-CD11b/c with flow cytometry. The ischemic injury model was established by exposing MSCs to hypoxia and serum deprivation (Hypoxia/SD). Cell viability and apoptotic rate were detected by trypan blue staining, CCK8 assays and Annexin V-FITC staining. The mRNA expressions of AT1-R, AT2-R and ACE were determined by Reverse Transcription-PCR and Real-time Quantitative PCR, The expression of AT1-R, AT2-R and ACE protein were measured by Western-blot. Results:MSCs expressed CD29, but not the CD11b/c. The purity of MSCs employed was up to 97%. The results of trypan blue staining along with CCK8 and Annexin V-FITC staining proved that the injury model induced by Hypoxia/SD was successfully established. MSCs under hypoxia and serum deprivation for 24 h induced a rapid increase in mRNA expression of AT1-R, AT2-R and ACE as well as their protein expressions. Conclusion:The local RAS in MSCs is activated by Hypoxia/SD stimulation and the mRNA and protein expressions of AT1-R, AT2-R and ACE are up-regulated.