Protective effect of oxymatrine on chronic heart failure and ADMA metabolism pathway in isoproterenol-induced chronic heart failure in rats / 中国中药杂志

<p><b>OBJECTIVE</b>To investigate the protective effects of oxymatrine on chronic heart failure induced by isoproterenol (ISO) and to observe its effects on ADMA metabolism pathway in ISO-induced chronic heart failure in rats.</p><p><b>METHOD</b>Male Sprague-Dawley rats were given oxymatrine (100,50 mg kg-1) orally for 14 days. Heart failure was induced in rats by subcutaneous injection of isoproterenol (5 mg kg-1 d-1 ) at the 8th day for 1 week. Serum parameters, haemodynamic parameters, Heart weight, and histopathological variables were analysed. Expression of protein levels were measured by Western blot.</p><p><b>RESULT</b>Oxymatrine (100,50 mg kg-1) significantly attenuated serum content of cTn I, improved left ventricle systolic and diastolic function and left ventricular remodeling, reduced the ISO-induced myocardial pathological changes compared with ISO group. In addition, oxymatrine (100,50 mg kg-1) significantly reduced serum level of ADMA (P <0. 01), normalize the reduced dimethylarginine dimethylaminohydrolase 2 (DDAH2) expression (P <0. 01) , but had no effect on the isoproterenol-induced upregulated protein arginine methyltransferases 1 expression.</p><p><b>CONCLUSION</b>Oxymatrine could ameliorate the experimental ventricular remodeling in ISO-induced chronic heart failure in rats and the mechanism involved in reducing serum content of ADMA and increased DDAH2 expression.</p>

Study on inhibitory effect of lycium pigment on lipopolysaccharide-induced uveitis in rats and its mechanism / 中国中药杂志

<p><b>OBJECTIVE</b>To investigate the inhibitory effect of lycium pigment on lipopolysaccharide (LPS)-induced uveitis in rats and its mechanism.</p><p><b>METHOD</b>The rat uveitis model was established by 30-day oral administration of lycium pigment (50, 100, 200 mg x kg(-1)) and footpad injection of LPS. Ocular tissues were collected for a histopathological inspection. The protein, nitric oxide and ADMA in aqueous humor, level of inducible nitric oxide synthase (iNOS) in retina, activities of serum total antioxidant capacity (T-AOC), superoxide dismutase (SOD) and glutathione peroxidase (GSH-PX), and content of malondialdehyde (MDA) were determined by using Western blot, ELISA and biochemical methods.</p><p><b>RESULT</b>According to the pathological study, lycium pigment (50, 100, 200 mg x kg(-1)) could notably reduce the inflammatory cell infiltration around corpus ciliare matrix of uveitis rats, and the concentration of protein and nitric oxide, and increased ADMA in aqueous humor. Lycium pigment (100, 200 mg x kg(-1)) could significantly inhibit the expression of iNOS in ocular tissues. In addition, lycium pigment (100, 200 mg x kg(-1)) also decrease the activities of serum T-AOC, SOD, GSH-PX, and the content of lipid peroxide MDA.</p><p><b>CONCLUSION</b>Lycium pigment has the inhibitory effect on LPS-induced uveitis in rats. Its mechanism is related to the regulation of nitric oxide/ADMA pathway and the improvement of oxidation resistance.</p>

Relaxant effects of matrine on aortic smooth muscles of guinea pigs / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To determine whether matrine, a kind of traditional Chinese medicinal alkaloid, can relax the aortic smooth muscles isolated from guinea pigs and to investigate the mechanism of its relaxant effects.</p><p><b>METHODS</b>Phenylephrine or potassium chloride concentration-dependent relaxation response of aortic smooth muscles to matrine was studied in the precontracted guinea pigs.</p><p><b>RESULTS</b>Matrine (1 x 10(-4) mol/L -3.3 x 10(3) mol/L) relaxed the endothelium-denuded aortic rings pre-contracted sub-maximally with phenylephrine, in a concentration-dependent manner, and its pre-incubation (3.3 x 10(-3) mol/L) produced a significant rightward shift in the phenylephrine dose-response curve, but had no effects on the potassium chloride-induced contraction. The anti-contractile effect of matrine was not reduced by the highly selective ATP-dependent K+ channel blocker glibenclamide (10(-5) mol/L), either by the non-selective K+ channel blocker tetraethylammonium (10(-3) mol/L), or by the beta-antagonist propranolol (10(-5) mol/L). In either "normal" or "Ca(2+)-free" bathing medium, the phenylephrine-induced contraction was attenuated by matrine (3.3 x 10(-3) mol/L), indicating that the vasorelaxation was due to inhibition of intracellular and extracellular Ca2+ mobilization.</p><p><b>CONCLUSION</b>Matrine inhibits phenylephrine-induced contractions by inhibiting activation of alpha-adrenoceptor and interfering with the release of intracellular Ca2+ and the influx of extracellular Ca2+.</p>

Metabolism of terephthalic acid and its effects on CYP4B1 induction / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To investgate the metabolism of terephthalic acid (TPA) in rats and its mechanism. Methods Metabolism was evaluated by incubating sodium terephthalate (NaTPA) with rat normal liver microsomes, or with microsomes pretreated by phenobarbital sodium, or with 3-methycholanthrene, or with diet control following a NADPH-generating system. The determination was performed by high performance liquid chromatography (HPLC), and the mutagenic activation was analyzed by umu tester strain Salmonella typhimurium NM2009. Expression of CYP4B1 mRNA was detected by RT-PCR. Results The amount of NaTPA (12.5-200 micromol x L(-1)) detected by HPLC did not decrease in microsomes induced by NADPH-generating system. Incubation of TPA (0.025-0.1 mmol x L(-1)) with induced or noninduced liver microsomes in an NM2009 umu response system did not show any mutagenic activation. TPA exposure increased the expression of CYP4B 1 mRNA in rat liver, kidney, and bladder.</p><p><b>CONCLUSION</b>Lack of metabolism of TPA in liver and negative genotoxic data from NM2009 study are consistent with other previous short-term tests, suggesting that the carcinogenesis in TPA feeding animals is not directly interfered with TPA itself and/or its metabolites.</p>

Effects of terephthalic acid on rat lipid metabolism / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To study the effect of terephthalic acid (TPA) on lipid metabolism in Sprague-Dawley (SD) rats.</p><p><b>METHODS</b>Five groups of SD rats that ingested 0%, 0.04%, 0.2%, 1%, and 5% TPA, respectively, were included in a 90-day subchronic feeding study. Effects of TPA on levels of serum protein, total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL), total antioxidative capability (T-AOC), superoxide dismutase (SOD) and malondialdehyde (MDA) were observed. Urine samples were collected and analyzed for concentration of ion.</p><p><b>RESULTS</b>TPA decreased the level of serum T-AOC in a dose dependent manner. The contents of serum and bladder MDA significantly decreased in 1% and 5% TPA ingestion groups. Serum CuZn superoxide dismutase (CuZnSOD) lowered in groups of 0.2%, 1%, and 5% TPA. TPA subchronic feeding had no significant influences on serum TC, LDL or HDL, but increased serum TG, TP and ALB after administration of 0.04% and/or 0.2% TPA. Concentrations of urinary Ca2+, Mg2+, Na+, and K+ were elevated in 1% and 5% TPA groups.</p><p><b>CONCLUSION</b>Antioxidative potential decreased after TPA exposure. MDA increase in serum and bladder tissues was one of the most important reactions in rats which could protect themselves against TPA impairment. The decrease of serum CuZnSOD was related to the excretion of Zn2+.</p>

Effects of fenvalerate on steroidogenesis in cultured rat granulosa cells / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>This study was designed to examine the in vitro effects of fenvalerate on steroid production and steroidogenic enzymes mRNA expression level in rat granulosa cells.</p><p><b>METHODS</b>Using primary cultured rat granulosa cells (rGCs) as model, fenvalerate of various concentrations (0, 1, 5, 25, 125, 625 micromol/L) was added to the medium for 24 h. In some cases, optimal concentrations of 22(R)-hydroxycholesterol (25 micromol/L), Follicle stimulating hormone (FSH, 2 mg/L), or 8-Bromo-cAMP (1 mmol/L) were provided. Concentrations of 17 beta-estradiol(E2) and progesterone (P4) in the medium from the same culture wells were measured by RIA and the steroidogenic enzyme mRNA level was quantified by semi-quantitative RT-PCR.</p><p><b>RESULTS</b>Fenvalerate decreased both P4 and E2 production in a dose-dependent manner while it could significantly stimulate rGCs proliferation. This inhibition was stronger in the presence of FSH. Furthermore, it could not be reversed by 22(R)-hydroxycholesterol or 8-Bromo-cAMP. RT-PCR revealed that fenvalerate had no significant effect on 3 beta-HSD, but could increase the P450scc mRNA level. In addition, 17 beta-HSD mRNA level was dramatically reduced with the increase of fenvalerate dose after 24 h treatment.</p><p><b>CONCLUSION</b>Fenvalerate inhibits both P4 and E2 production in rGCs. These results support the view that fenvalerate is considered as a kind of endocrine-disrupting chemicals. The mechanism of its disruption may involve the effects on steroidogenesis signaling cascades and/or steroidogenic enzyme's activity.</p>

Induction of bladder lesion by terephthalic acid and its mechanism / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To provide more information for rational evaluation of potential risks of terephthalic acid (TPA), we studied the effects of TPA on rats' bladders in 90 days after TPA exposure.</p><p><b>METHODS</b>Sprague Dawley rats were subdivided into five groups, ingesting 0%, 0.04%, 0.2%, 1%, and 5% TPA respectively for a sub-chronic feeding study lasting for 90 days. Urine, serum and samples of brain, liver, lung, kidney, bladder, etc. were collected and analyzed.</p><p><b>RESULTS</b>TPA ingesting decreased the value of urinary pH, and increased the contents of Ca2+, Zn2+, Mg2+, Na+, K+ in urine. The volume of 24 h urine was significantly increased in male rats in the 1% and 5% TPA groups. Urinary white sediment was found in both sexes, and its formation in male rats seemed more susceptible than that in female rats. Alpha 2u-globulin (AUG) in serum and urine of male rats was markedly increased in a dose-dependent manner. Fifteen cases of hyperplasia (simple or atypical) were determined in the 5% TPA ingesting group, 14/52 in male rats and 1/23 in female rats. Among them 3 male rats had no stone or calculus. Those with either bladder stones or hyperplasia were accompanied with urinary white sediments.</p><p><b>CONCLUSION</b>White sediment accompanied with elevated urine AUG is the basis of TPA induced urolith formation, and is also associated with TPA induced bladder epithelial cell proliferation. It can act as an early biomarker for the potential toxic effect of TPA.</p>