Improvement of myocardial glycolipid metabolic disorder in diabetic hamster with Astragalus polysaccharides treatment.

The objective of the present study is to observe the effect of Astragalus polysaccharide (APS) on myocardial glucose and lipid metabolism in diabetes (DM) hamster and to explore its mechanism in intervention of DM cardiomyopathy. Low-dose- streptozotocin-induced hamsters (STZ, 40 mg/kg × 3 days, i.p.) with blood glucose >13.9 mmo/L were considered as type 2 diabetic models. We measure blood glucose, serum lipid, insulin, C-peptide, myocardial enzyme levels, myocardial glycogen staining, myocardial ultrastructure, fluorescence quantitative RT-PCR detection of myocardial PPAR-α and the target genes (FATP, ACS) and GLUT4 mRNA expression in normal control group, DM group and APS treatment group hamsters. There was significant glycolipid metabolic disorders in DM group compared with normal group. Glucose, glycosylated serum protein, myocardial enzymes and lipid levels in APS treatment group decreased significantly than DM group, but insulin and C-peptide levels was no difference. Myocardial glycogen staining and abnormal myocardial ultrastructure in APS treatment group were significantly improved than in DM group. Gene expression of myocardial PPAR-α and its target genes (FATP, ACS) in APS group were significantly lower than in DM group, while gene expression of GLUT4 in APS group was higher than DM group. APS can partially improve myocardial glucose and lipid metabolism disorders in diabetic hamsters and protect myocardium in some extent.

Astragalus polysaccharides inhibited diabetic cardiomyopathy in hamsters depending on suppression of heart chymase activation.

Diabetic cardiomyopathy is associated with high morbidity and mortality of heart failure. Overactivation of the local chymase-Ang II system plays a dominant role in diabetic cardiomyopathy. Astragalus polysaccharide (APS) is used in traditional Chinese medicine to boost immunity. To study the effect of APS on local system of chymase-Ang II in diabetic cardiomyopathy, we investigated APS/normal saline (NS)-administrated streptozotocin-induced diabetic hamsters. After APS/NS administration at a dose of 1 g/kg per day for 10 weeks, hemodynamic parameters, levels of insulin (INS), C-peptide (C-P), glycosylated serum protein (GSP), lipoproteins, myocardial enzymes, and Ang II (plasma and myocardial) were tested; myocardial collagen (type I and III), myocardial ultrastructure, and activities of matrix metalloproteinase (MMPs) were measured; activities and expression of cardiac chymase and ACE were detected by using quantitative real-time RT-PCR and RIA; protein expression of cardiac phosphoric extracellular signal-regulated kinase 1/2 (p-ERK1/2) was measured by Western blot. AP-administrated diabetic hamsters had lower levels of GSP, lipoproteins, myocardial enzymes, myocardial Ang II, expression of collagen I and I/ III, activities of pro-MMP-2 and MMP-2, activities and expression of chymase, and expression of p-ERK1/2 than NS-administrated diabetic hamsters and could better protect the myocardial ultrastructure. There was no difference in hemodynamic parameters between two groups. These results indicate that APS could inhibit diabetic cardiomyopathy in hamsters depending on the suppression of the local cardiac chymase-Ang II system.

Beneficial effects of astragalus polysaccharides treatment on cardiac chymase activities and cardiomyopathy in diabetic hamsters.

Over-activation of the local chymase-angiotensin II (Ang II) system has a dominant role in diabetic cardiomyopathy. Astragalus polysaccharides (APS) are used in traditional Chinese medicine to boost immunity. In this study, we investigated the effects of APS treatment on cardiac function, myocardial collagen expression, cardiac ultrastructure, cardiac matrix metalloproteinase (MMP) activity, levels of plasma glycosylated serum protein (GSP), and myocardial enzymes, and the expression of Ang II, chymase, and angiotensin-converting enzyme (ACE) in the diabetic hamster myocardium. Diabetes was induced by a single injection of streptozotocin (60 mg/kg ip). The experimental groups consisted of normal control (n = 15), diabetic (n = 15), insulin-treated diabetic (n = 15, NPH 1-2 U/day ip), and APS-treated diabetic (n = 30, APS 1-2 g/kg/day orally for 10 weeks) hamsters. Diabetic hamsters treated with insulin or APS exhibited significantly decreased blood glucose, plasma GSP, and myocardial enzymes, as well as improvements in cardiac function and cardiac ultrastructure. Compared with insulin treatment, APS treatment significantly reduced myocardial collagen (type I and III) expression and lowered cardiac MMP-2 activity, myocardial Ang II levels, myocardial chymase expression, and p-ERK1/2 kinase expression. In diabetic hamsters, myocardial ACE expression and plasma Ang II levels was not altered by insulin or APS treatment. These results indicate that treatment of diabetic hamsters with APS inhibited the local chymase-Ang II system and improved markers of diabetic cardiomyopathy.

Effects of Astragalus polysaccharides on chymase, angiotensin-converting enzyme and angiotensin II in diabetic cardiomyopathy in hamsters.

This study investigated the effects of Astragalus polysaccharides (APS), the main active extract from the traditional Chinese medicinal herb Astragalus membranaceus, on myocardial chymase, angiotensin-converting enzyme (ACE) and angiotensin II (Ang II) in diabetic cardiomyopathic hamsters. Plasma levels of insulin, C-peptide and glycosylated serum protein (GSP), plasma and myocardial levels of Ang II, and myocardial gene expression and activity of chymase and ACE were measured after treatment with APS at a dose of 1 g/kg per day or 1 ml of normal saline per day (controls) for 10 weeks. GSP levels, myocardial Ang II levels, and myocardial gene expression and activity of chymase were significantly decreased in diabetic hamsters after treatment with APS compared with controls. These results suggest that APS can inhibit the local chymase-Ang II system in diabetic cardiomyopathy.

[The expression of galectin-3 in nodular thyroid goitre].

OBJECTIVE: To investigate the expression of galectin-3 in benign and malignant thyroid nodules. METHODS: Galectin-3 expression was assayed with immunohistochemical and RT-PCR methods in thyroid specimens. RESULTS: The majority of the specimens of thyroid carcinomas expressed galectin-3 with immunohistochemical and RT-PCR methods (89.7% and 91.7%) and the expression was significantly in different histological types. Papillary and follicular thyroid malignancies showed high expression of galectin-3 (100% positive). Comparing the specimens of thyroid carcinomas with metastases and those without metastases, the expression of galectin-3 was significantly higher in the former than in the latter. Among 25 specimens of benign adenomas and 13 specimens of nodular hyperplasia, only 3 were weakly positive and other were negative. Neither 10 specimens of normal thyroid tissue nor 25 specimens of paracarcinomatous thyroid tissue expressed galectin-3. CONCLUSION: Galectin-3 may be used as a marker for differentiating benign and malignant thyroid nodules.

Determination of vitamin C in plasma and dialysate from uremia patients by high performance liquid chromatography with electrochemical detection.

A convenient and valid method for the determination of ascorbic acid(AA) and dehydroascorbic acid(DHAA) in plasma and dialysate from patients with uremia by high performance liquid chromatography with electrochemical detection is described. A mixture of 0.8 g/L metaphosphoric acid and 18% (volume fraction) perchloric acid was used as a protein precipitant and the extractant for AA from biosamples. It was also a good stabilizer for AA in samples. The proposed method is satisfied for routine screening of vitamin C in clinical applications with a correlation coefficient of more than 0.99 in the range of 2 mumol/L-40 mumol/L AA. The within-day precision was less than 8.9% and 10.55% for AA and DHAA, respectively. The recoveries of AA in plasma and dialysate were over 95% and 78%, respectively.