镉诱发大鼠肾重吸收钙障碍的机理(英文)

给雄性Wistar大鼠sc不同剂量的镉金属硫蛋白(CdMT),结果表明镉接触组尿镉、尿钙和尿蛋白浓度都高于对照组,并与镉剂量间存在剂量效应关系,而血清游离钙浓度无变化;镉接触组肾皮质钠泵和钙泵活性低于对照组,体外试验结果也显示镉能抑制钙泵活性,谷胱甘肽(GSH)和半胱氨酸对这种抑制有保护作用}镉接触组肾皮质GSH含量低于对照组,而丙二醛(MDA)含量则高于对照组,高剂量组肾皮质cAMP/cGMP比值低于对照组。肾皮质钙泵活性、cAMP/cGMP比值、GSH含量三者都与尿钙浓度间呈负相关,MDA含量则与尿钙呈正相关,揭示镉引起的钙尿症是由肾重吸收钙障碍造成的,可能与镉引起的肾脏钠泵、钙泵、环核苷酸、GSH和脂质过氧化等改变有关。

尿钙结石患者和健康人群饮食及尿液成石风险因素的对比

目的评估比较特发性肾结石患者和健康人群的饮食习惯以及成石尿液风险因素。方法选取108例肾结石患者和210例健康成人,评估比较其饮食习惯及形成石的尿液风险因素。所有受试者均在1年时间内完成。通过调查问卷,了解受试者的饮食习惯和个人特征,并对受试者进行尿生化等检查。结果肾结石患者中,有结石家族史的患者较健康成人者多,分别为42.9%、17.6%。肾结石患者的体质量较健康成人重,分别为76.8 kg、72.8 kg。肾结石患者钙摄入量较健康人少,分别为(794.8±294.1)mg、(943.6±345.4)mg。尿生化检查结果显示,肾结石患者的钙和草酸排量、尿素氮和尿素含量均较高。在肾结石患者和健康受试者中,尿钙和尿素的相关性均很明显,但是在肾结石患者中更加明显。尿钙和尿钠只在健康受试者中有存在相关性。结论肾结石患者和健康人群的主要统计学差异表现在结石家族史、高体质量、日常低钙摄入和较高的草酸钙排,这些结果揭示了基因和饮食营养因素在肾结石发病机制中存在联合作用。

实验性镉中毒大鼠尿钙症及其机理的探讨

经皮下一次注射镉金属硫蛋白诱发大鼠急性中毒,作为慢性镉中毒之模型,观察中毒大鼠肾皮质的组织病理学改变和脂质过氧化作用,测定尿液主要生化指标变化。结果显示尿总蛋白、葡萄糖含量,r-谷氨酰转移酶、碱性磷酸酶、N-乙酰-β-D-氨基葡萄糖苷酶活性均明显增加,尿钙增加较早。结合光镜和电镜下肾近曲小管病损,以及肾皮质脂质过氧化作用加剧,提示肾脏钙代谢紊乱是镉中毒性肾损害的始动因素,脂质过氧化作用是镉中毒性肾损害的机理之一。

Structure and Composition of Non-Infectious Phosphate Calculi Formed in Patients with Low and High Urinary Phosphate Concentrations

Objective: The aim of this paper was to assess the relationships among chemical, phase and structural composition and?etiopathogenic factors of non-infectious phosphate calculi formed in patients with low and high urinary phosphate concentrations, and to characterize the mechanism of their formation related on biochemical results. Material and Methods: Twelve samples of phosphate renal calculi were obtained, 4 from patients with low phosphaturia and 6 from patients with high urinary phosphate concentrations. Their chemical composition was determined qualitatively by energy dispersive X-ray analysis and quantitatively by spectrophotometric and thermal analysis;and their phase composition was determined by Fourier transform infrared transmission spectroscopy and X-ray diffraction. The structure of the calculi was assessed by scanning electron microscopy. Results: Non-infectious phosphate renal calculi of patients with low phosphaturia consist of poorly crystalline carbonate hydroxyapatite, whereas those of patients with high urinary phosphate concentrations consist of poorly crystalline hydroxyapatite with some amount of calcium oxalate crystals. Calculi of patients with high urinary phosphate concentrations are formed at urinary supersaturation with respect to hydroxyapatite and calcium oxalate about 4 times higher than in patients with low phosphaturia. Conclusion: In patients with low phosphaturia, the non-infectious phosphate renal calculi are formed in urine near pH 7 and contain only poorly crystalline carbonate hydroxyapatite. In patients with high urinary phosphate concentrations and hypercalciuria, the calculi are formed in urine near pH 6 and consist of both poorly crystalline hydroxyapatite and some amount of calcium oxalate crystals.

CdMT对大鼠的急性毒性与脂质过氧化的关系

一次皮下注射不同剂量CdMT(0,0.3,0.6和0.9mgCd/kg)后12小时,大鼠肝GSH、MDA和TG无明显变化,但引起肾皮质GSH含量降低、MDA含量增高、钙尿症和蛋白尿,且都与给予的镉剂量间存在剂量效应关系。肾皮质GSH和MDA含量均与尿钙和尿蛋白浓度间存在相关关系。提示LPO是引起镉肾毒性的机理之一,而LPO可能与GSH耗竭有关。