Protection of rhein on IgA nephropathy mediated by inhibition of fibronectin expression in rats.

OBJECTIVE: To investigate the protective effects of rhein on IgA nephropathy (IgAN) in the rat model. MATERIALS AND METHODS: Twenty-eight female sprague dawley rats were divided randomly into four groups, namely control, IgAN, rhein-prevented and rhein-treated. The pathologic changes on renal tissue were observed by the H and E, staining and the amount of urinary red blood cells and 24-h urinary protein excretion were measured. The glomerular deposition of immune globulin A (IgA) was measured by immunofluorescence staining. Fibronectin (FN) and α-smooth muscle actin (α-SMA) expression on renal tissue were measured via immunohistochemistry. RESULTS: The model of IgAN was established according to Bovine serum albumin-Lipopolysaccharide-Carbon tetrachloride protocol, which was evidenced by histological structural lesions of glomeruli, IgA deposition and urinary measurement. Histological examination of kidney sections from both rhein-prevented group and rhein-treated group showed that glomerular hypertrophy, mesangial expansion, excessive extracellular matrix, and renal capsule dilation were markedly ameliorated compared with IgAN group. Moreover, rhein treatment significantly reduced IgA deposition in glomerulus, the volume of urinary red blood cells and 24-h urinary protein excretion. More importantly, increased FN expression in IgAN was back to normal level in rhein-prevented and rhein-treated group, which was along with the reduction of α-SMA expression in renal tissues. CONCLUSIONS: These findings indicate that rhein prevents the development of glomerulosclerosis and halts the progression of IgAN via inhibition of FN and α-SMA expression.

Influence of induced nitric oxide synthase expression on apoptosis of thymocyte in burn rats / 中华烧伤杂志

<p><b>OBJECTIVE</b>To investigate the influence of induced nitric oxide synthase (iNOS) expression on apoptosis of thymocyte in burn rats, and to explore the relationship between NO and pathological lesion of the thymus gland in burn rats.</p><p><b>METHODS</b>Fifty-six male Wistar rats were enrolled in the study and randomized into control( C, n = 8,without treatment) , burn ( B, n = 24) , and S-methylisothiourea( SMT, n = 24) groups. Equal amount of isotonic saline solution and SMT(7. 5 mg/kg) were respectively intravenously infused into the rats in B and SMT groups after being inflicted with 30% TBSA full-thickness burns. The weight of thymus gland in each group were weighed, and thymocyte apoptosis and iNOS expression were determined with TUNEL method and immunohistochemistry, respectively at 6,24,72 postburn hours( PBH) , with 8 rats at each time-point. The number of apoptotic cells and the density of iNOS positive cells in thymus was measured by stereological method.</p><p><b>RESULTS</b>The weight of thymus in B group at 24 and 72 PBH [ (153+/- 14) , (91+/-22) mg] were obviously heavier than those in C group, but much lighter than those in SMT group ( P < 0.01). A few apoptotic cells and iNOS positive cells were observed in cortex and medulla of thymus in C group, while they were observed in B group at 6 PBH, and the number of cells began to increase at 24 PBH, distributing in medulla,parenchyma, the boundary of cortex, and medulla under capsule. The iNOS positive cells in B group at 24 PBH were distributed around the interlobular septum. A large number of cortical cells with brown staining were observed in B group at 72 PBH, and the number of iNOS positive cells also increased, with scattered distribution and clear cell boundary. Fewer positive cells with uneven distribution, no iNOS positive cells, and few apoptotic foci were observed in SMT group after burns. The density of apoptotic cells in B group at 24 and 72 PBH was (2. 428 +/-0. 728) x 10(-5)/microm(3) and (5. 586 +/- 1.233) x 10(-5)/microm(3), respectively, which was obviously higher than that in C and SMT group. The density of iNOS positive cells in B group was increased in a time-dependent manner( P <0. 05).</p><p><b>CONCLUSION</b>The apoptotic rate of thymocyte in severely burn rats increases early after burns. The up-regulation of iNOS expression in thymus can promote apoptosis of thymocytes, while SMT can partially ameliorate this phenomenon.</p>