[Causes of death in STZ-induced rat models of diabetes mellitus].

OBJECTIVE: To identify conditions that may improve the successful rate of STZ-induced rat models of diabetes mellitus (DM). METHODS: 100 male SD rats were randomly divided into control group (n = 10) and experimental group (n = 90). Rats in the experimental group were treated with intraperitoneal injection of STZ 65 mg/kg once, and were then categorized into succeeded DM model group and failed group. Their body masses and levels of fasting blood glucose (FBG), urine glucose (UG), urine protein (UP), urine routine, renal function, liver function, blood lipids and kidney hypertrophy index (KHI) were monitored and compared. Dead rats were dissected to observe diseased organs. Pathological changes of those diseased organs were examined by HE staining. RESULTS: DM rat models were established through a single intraperitoneal injection of STZ, with a success rate of 58.89%. During the experiment, 43.33% of rats died. Compared with the rats in the failed group, the DM rat models had significantly higher levels of body mass, food intake, water intake, urine output, FBG, creatinine, blood urea nitrogen, KHI, urinary tract infections, and mortality; but lower levels of total protein, albumin and cholesterol and triglyceride (P < 0.05). Nine rats died of pulmonary edema; 19 died of renal abscess. The causes of 11 dead rats were not clear. CONCLUSION: DM rat models can be established through a single intraperitoneal injection of STZ 65 mg/kg, but with high mortality rate. The deaths may be associated with infection, malnutrition, suffocation of lymphatic circulation, toxicity of STZ, and changes in environmental and climate conditions.

[Investigate the effects of compound radix notoginseng on renal interstitial fibrosis and kidney-targeting treatment].

OBJECTIVE: Investigate the effects of compound Radix Notoginseng on renal interstitial fibrosis and kidney-targeting treatment. METHODS: 100 healthy Sprague-Dawley rats were randomly divided into 5 groups: Unilateral ureteral obstruction (UUO) group, sham-operation (SOR) group, Radix Notoginseng (RN) group, compound Radix Notoginseng (CRN) group and Losartan (ARB) group. After operation, RN, CRN and ARB groups were intragastric administrated with RN (3 mL/d), CRN (3 mL/d) and ARB [20 mg/(kg x d)] respectively. Each group randomly included 18 rats for statistical analysis. The histological changes of renal interstitial tissues were observed by HE, Masson and PAS staining. Total kidney collagen content was determined by measuring the amount of hydroxyproline. The mRNA of alpha-SMA, collagen I and fibronectin were reverse transcribed and quantified by real-time PCR. The expression of alpha-SMA protein was assessed by immunohistochemistry and Western blot analysis. RESULTS: In UUO model, the obstructed kidney showed typical features of renal tubulointerstitial fibrosis, such as severe tubular loss, dilation, atrophy, infiltration of inflammatory cells, interstitial matrix deposition (P < 0.05). Partial correlation assay showed that the expression of alpha-SMA was related to the renal tubular injury (r = 0.55; P < 0.05). Administration of RN, CRN and ARB improved tubulointerstitial damage and collagen matrix accumulation induced by UUO in different degree. The expression of the alpha-SMA at mRNA and protein levels were significantly increased in the UUO group (P < 0.05), which was also suppressed by treatment with RN, CRN and ARB in different degree. Moreover, more effective role in preventing fibrosis was observed in CRN group than when compared with that of RN group. CONCLUSION: RN and CRN can inhibit UUO-induced renal interstitial fibrosis in rats, and CRN treatment is more effective than RN in reducing interstitial fibrosis.

[Serological screening of autoantigens associated with vasculitis in systemic lupus erythematosus].

OBJECTIVE: To screen autoantigens associated with vasculitis in systemic lupus erythematosus (SLE) by serological analysis of recombinant cDNA expression library (SEREX). METHODS: A cDNA expression library derived from human microvascular endothelial cells (HMVEC) was screened with pooled sera from patients with SLE. Pooled sera were preadsorbed to reduce the background sera activity. The obtained preadsorbed pooled sera of patients were used for immunoscreening. Immunoscreening procedure was done according to the instruction manual provided by the manufacturer (Stratagene). RESULTS: Eleven distinct positive clones were identified. Bioinformatic analysis revealed these 11 positive clones encoding three different proteins: SSA, SSB and YB-1. As for YB-1, there are hitherto no reports unveiling its association with vasculitis in SLE. CONCLUSION: The association of YB-1 with vasculitis in SLE was found for the first time in this study. SEREX has offered a new strategy to explore the autoantigens related to SLE. By SEREX, we may find out the autoantigen which is helpful to the diagnosis and treatment of SLE, and to the prognostication concerned.