芭蕉芯和维生素B6对小鼠草酸钙结晶的抑制作用

观察了维生素Ｂ_６和芭蕉芯提取液对实验性高草酸尿症小鼠体内草酸钙结晶形成的抑制作用。结果发现：湿肾组织钙含量各组之间无显著性差异；湿肾组织草酸含量，维生素Ｂ_６治疗组为０．６９８０±０．４０８２μｍｏｌ／ｇ，芭蕉芯提取液治疗组为０．４０３１±０．２１４７μｍｏｌ／ｇ，均分别明显低于成石组（Ｐ＜０．０５及Ｐ＜０．０１）。偏光显微镜观察发现，服用维生素Ｂ_６及芭蕉芯提取液的小鼠肾脏草酸钙结晶形成明显少于成石组。结果表明：维生素Ｂ_６和芭蕉芯提取液都具有抑制实验性高草酸尿症小鼠肾脏草酸钙结晶形成的作用，其中，芭蕉芯提取液的抑制作用明显比维生素Ｂ_６强。     

Inhibitory effects of taraxasterol and aqueous extract of Taraxacum officinale on calcium oxalate crystallization: in vitro study

Objective: We investigated and compared the effects of taraxasterol, aqueous extract of T. officinale (AET) aerial part, and potassium citrate (PC) on calcium oxalate (CaOx) crystallization in vitro.

Materials and methods: CaOx crystallization was induced by adding sodium oxalate to synthetic urine. Taraxasterol (2.5, 5, 7.5 and 12.5?μg/mL), extract (1, 2, 4 and 8?mg/mL), and PC (100, 150, 200 and 350?mg/mL) were subjected to anti-crystallization activities. The absorbance and %inhibition of nucleation of CaOx crystals were evaluated by spectrophotometer at 2, 4, 6, 8, 10, 20, 30, 40, 50 and 60?min and the number and morphology of crystals were studied by light microscopy after 60?min.

Results: Presence of taraxasterol, extract and PC decreased absorbance in experimental samples compared to control, significantly. The nucleation of crystals is inhibited by taraxasterol, extract, and PC (26–64, 55–63 and 60–70%, respectively). The number of CaOx crystals were decreased in presence of taraxasterol (p?p?p?2O₄ monohydrate, while increased CaC₂O₄ dihydrate crystals, significantly. Also, the diameter of CaC₂O₄ dihydrate crystals was decreased in presence of taraxasterol, extract and PC, significantly.

Conclusions: This research indicated that taraxasterol and extract have anti-crystallization activities and effectiveness of the extract is more potent than taraxasterol. It could be because of another constituent in the extract with the synergistic effect.     

Characterization of Tamm-Horsfall protein in a rat nephrolithiasis model

PURPOSE: The role of Tamm-Horsfall protein in calcium oxalate stone formation is controversial. It is unclear whether Tamm-Horsfall protein has a role in crystallization. If it does, does it act as an inhibitor or promoter of crystallization? To elucidate the nature of its involvement we characterized Tamm-Horsfall protein in a rat model of calcium oxalate nephrolithiasis by in vivo and in vitro techniques. MATERIALS AND METHODS: Calcium oxalate nephrolithiasis was induced in male Sprague-Dawley rats. The amino acid and carbohydrate composition of Tamm-Horsfall protein from normal rats and those with nephrolithiasis was determined. The Tamm-Horsfall protein gene and protein expression in the kidneys were examined by in situ hybridization and immunohistochemistry. Furthermore, the interaction of Tamm-Horsfall protein and calcium oxalate crystals was assessed by an in vitro crystal aggregation assay. RESULTS: Tamm-Horsfall protein from rats with nephrolithiasis was biochemically similar to that from normal rats. Although Tamm-Horsfall protein was associated with crystal deposits in the renal papillae of rats with nephrolithiasis, Tamm-Horsfall protein messenger RNA expression in the kidneys remained unchanged. In each group Tamm-Horsfall protein inhibited calcium oxalate crystal aggregation by 47%, indicating no change in functional capabilities. CONCLUSIONS: The results of this study indicate that urinary excretion, and the biochemical nature and functional capabilities of Tamm-Horsfall protein remain unchanged during experimental calcium oxalate nephrolithiasis. Although staining for Tamm-Horsfall protein was evident in the papillae of rats with nephrolithiasis, the site of Tamm-Horsfall protein synthesis remained cells of the thick ascending limbs of the loop of Henle.     

Effects of high-sodium diet on lithogenesis in a rat experimental model of calcium oxalate stones

BackgroundThis study aimed to investigate the effects of a high- and low-sodium diets on lithogenesis in a rat experimental model of calcium oxalate stones.MethodsTwenty male Wistar rats were randomly divided into four groups; group A: 4% NaCl+1% ethylene glycol (EG); group B: 8% NaCl+1% EG; group C: 8% NaCl+normal drinking-water; group D: 1% EG +normal diet. All rats were sacrificed 4 weeks later, and blood samples were collected from the heart. The kidneys were collected for Von Kossa staining to evaluate the formation of calcium-containing crystals. The last 24-h urine samples were also gathered for metabolic analysis.ResultsVon Kossa staining demonstrated that the rats in both group A and group B had significantly more renal calcium crystals than those in group D. However, 24-h urinary volume increased significantly (142.26±20.91 mL) in group B compared with group A (100.52±28.23 mL), group C (107.36±14.24 mL), group D (40.79±8.71 mL) (P=0.004, 0.012, and 0.000 respectively). Level of urine sodium (Na), potassium (K), chlorine (Cl), and calcium (Ca), urea nitrogen were significantly higher in group B compared with group D. The urine phosphorus, oxalate, and creatinine levels; urine specific gravity; and urine PH were similar between group B and group D. The level of serum sodium was higher in group B (151.26±4.06 mmol/L) compared with group D (145.56±1.12 mmol/L) (P=0.002).ConclusionsA high sodium intake might increase the risk of lithogenesis in susceptible individuals (given by EG) or in individuals with water restriction.     

Effects of apocynin and losartan treatment on renal oxidative stress in a rat model of calcium oxalate nephrolithiasis

Background  

Tissue culture studies found that renal epithelial cells suffer oxidative injury on exposure to high levels of oxalate (Ox) and calcium oxalate (CaOx) crystals; nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, a major source of reactive oxygen species (ROS) production in kidney, has been shown to be involved in this event. The present study aimed to investigate whether this in vitro feature of NADPH oxidase could be confirmed in vivo.     

Protective effects of pretreatment with Radix Paeoniae Rubra on acute lung injury induced by intestinal ischemia/reperfusion in rats

Objective： To investigate the effect of pretreatment with Radix Paeoniae Rubra （RPR） on acute lung injury induced by intestinal ischemia/reperfusion in rats and its protective mechanism.
Methods： Thirty-two Wistar rats were randomly divided into four groups： Sham-operation group, ischemla/ reperfusion group （I/R group ）, RPR-pretreatment group and hemin group. The model of intestinal ischemia/ reperfusion was established by clamping the superior mesenteric artery for 1 hour followed by 2-hour reperfusion. The effect of RPR on the expression of heme oxygenase-1 （HO-1） in lung tissues was detected by immunohistochemistry and morphometry computer image analysis. Arterial blood gas analysis, lung permeability index, malondialdehyde （MDA） and superoxide dismutase （SOD） contents in lungs were measured. The histological changes of lung tissue were observed under light microscope.
Resalts： The expression of HO-1 in RPR-pretreatment group and hemin group was obviously higher than that in sham-operation group and I/R group （ P 〈 0.01 ）. The level of MDA and lung permeability index in RPR-pretreatment and hemin group were significantly lower than those in I/R group （P〈0.01 or P〈0.05）, while the activity of SOD in RPR-pretreatment and hemin group was obviously higher than that in I/R group （P〈0.01）. Under light microscope, the pathologic changes induced by I/R were significantly attenuated by RPR.
Conclusion： Intestinal ischemia/reperfusion may result in acute lung injury and pretreatment with RPR injection can attenuate the injury. The protective effect of RPR on the acute lung injury is related to its property of inducing HO-1 expression and inhibiting lipid peroxidation.     

Decreased renal expression of the putative calcium oxalate inhibitor Tamm-Horsfall protein in the ethylene glycol rat model of calcium oxalate urolithiasis

PURPOSE: Tamm-Horsfall protein is believed to inhibit calcium oxalate crystallization, aggregation or adhesion to the renal epithelium. We determined whether ethylene glycol induced urolithiasis changes the expression of renal and urinary Tamm-Horsfall protein. For comparison the expression of another calcium oxalate inhibitor, osteopontin, was also analyzed. MATERIALS AND METHODS: Male rats were treated with 0.75% ethylene glycol plus an AIN-76 diet (Dyets, Bethlehem Pennsylvania) (ethylene glycol group) or standard rat chow and water (control group) for up to 8 weeks (6 per group for 8 weeks and 3 per group for 3 days to 6 weeks). Kidneys and urine (8 weeks only) were harvested and analyzed by Northern and Western blot analysis, and immunohistochemistry. RESULTS: Tamm-Horsfall protein message and protein (membrane bound form) were decreased, while those of osteopontin were increased in the kidneys of rats treated with ethylene glycol for 8 weeks. As judged by immunochemistry Tamm-Horsfall protein and osteopontin were consistently present in a few tubules in rats in the ethylene glycol and control groups, respectively. In urine expression of the free form of Tamm-Horsfall protein (approximately 75 kDa.) was decreased but detectable in ethylene glycol treated rats. Although readily detected in tissue, osteopontin was not detected in the urine of control or ethylene glycol treated rats. In the time course experiment Tamm-Horsfall protein did not decrease until 4 weeks, when calcium oxalate crystals were detectable in the kidneys of treated rats. In contrast, osteopontin was increased, although inconsistently, beginning at 3 days. CONCLUSIONS: Unlike other calcium oxalate inhibitors, such as osteopontin, renal message and protein for Tamm-Horsfall protein was decreased in ethylene glycol treated rats. Tamm-Horsfall protein expression did not decrease until aggregates of crystals had been deposited in the kidneys, while osteopontin expression began to increase almost immediately. Comparisons of the data on kidneys and urine obtained by RNA or protein blot analysis and immunochemistry underscore the need to examine tissue and urine by multiple techniques to obtain the most accurate assessment of how protein expression is changed by a given treatment.     

苦参灵芝发酵液在2.2.15细胞中抗HBV作用

比较苦参的灵芝发酵液和苦参与灵芝发酵液的混合液体外抗乙肝病毒(HBV)的效果.用HBVDNA转染的2.2.15细胞作为模型,放射免疫法测定2种药物作用后细胞培养上清液中HB sAg和HBeAg量,计算其对HBsAg和HBeAg分泌的抑制率,用MTT法检测细胞毒性.结果表明:剂量在12.5～200μg/mL的范围内,均能不同程度地减少细胞培养上清液中的HBsAg和HBeAg量,发酵液细胞的毒作用不明显,而混合液具有一定的细胞毒作用.结果显示发酵液具有一定的体外抗HBV作用.     

Klotho基因多态性与新疆地区维吾尔族特发性草酸钙肾结石的相关性研究

目的:探讨Klotho基因rs1207568与新疆地区维吾尔族特发性草酸钙肾结石的相关性。方法:选择400例维吾尔族草酸钙肾结石患者(病例组)和410例维吾尔族健康体检者(对照组),应用SNaPshot方法对Klotho基因rs1207568进行基因检测,并分析其与特发性草酸钙肾结石发病的相关性以及对血脂、血生化的影响。结果:对照组的基因型分布均符合Hardy-Weinberg平衡。病例组和对照组rs1207568基因型比较差异有统计学意义(P<0.01),且病例组携带等位基因C的风险高于对照组(OR=1.295,95%CI:1.019～1.645,P<0.05)。CC基因型患者的血钙、血磷、血氯、尿素氮、尿酸均高于CT+TT基因型,差异有统计学意义(P<0.05),而二者血镁、血钾、血钠水平比较差异无统计学意义。在血脂方面,二者甘油三酯(TG)、总胆固醇(TC)比较差异有统计学意义(P<0.05)。结论:Klotho基因rs1207568在维吾尔族人群中与特发性草酸钙肾结石发病风险显示有相关性,rs1207568C等位基因是其危险因素。     

补肾化痰方对去势骨质疏松大鼠钙沉积的影响

目的观察补肾化痰方对去势骨质疏松大鼠钙沉积的影响。方法 6月龄SD大鼠40只,随机分为4组,每组10只,即假手术组、模型组、补肾化痰组和补肾组。采用micro CT检测大鼠的骨密度((bone mineral density,BMD),酶联免疫吸附法(enzyme linked immunosorbent assay,ELISA)检测血清胎球蛋白(fetuin-A)、基质gla蛋白(matrix gla protein,MGP)水平,蛋白质印迹法(Western blot,WB)检测骨组织Fetuin-A、MGP蛋白的表达,免疫组化(immunohistochemical,IHC)检测其定位。结果与假手术组相比,模型组、补肾化痰组及补肾组的BMD均降低,血清Fetuin-A、MGP水平及骨组织Fetuin-A水平均降低,骨组织MGP水平升高,差异有统计学意义(P0.001);与模型组相比,补肾化痰组及补肾组的BMD均升高,血清Fetuin-A、MGP水平及骨组织Fetuin-A水平均升高,而骨组织MGP水平降低,差异有统计学意义(P0.001);补肾化痰组与补肾组相比较,补肾化痰组血清Fetuin-A、MGP水平升高明显,差异有统计学意义(P0.001),而两组的BMD、骨组织Fetuin-A、MGP含量则没有明显的差异(P0.05)。结论补肾化痰方能够影响血清胎球蛋白-基质gla蛋白-钙磷矿化复合物的形成,从而改善钙沉积,促进骨矿化,起到防治骨质疏松的作用。     

A traditional Chinese herbal antilithic formula,Wulingsan, effectively prevents the renal deposition of calcium oxalate crystal in ethylene glycol-fed rats

We investigated the effects of a traditional Chinese herbal formula, Wulingsan (WLS), on renal stone prevention using an ethylene glycol-induced nephrocalcinosis rat model. Forty-one male Sprague-Dawley (SD) rats were divided into four groups. Group 1 (n = 8) was the normal control; group 2 (n = 11) served as the placebo group, and received a gastric gavage of starch and 0.75% ethylene glycol (EG) as a stone inducer; group 3 received EG and a low dose of WLS (375 mg/kg); and group 4 received EG and a high dose of WLS (1,125 mg/kg). Baseline and final 24 h urine samples were collected individually; biochemical data of urine and serum were also obtained at the beginning and at the end of the experiment. After 4 weeks, animals were killed and kidneys were harvested. The kidney specimens were examined by polarized light microscopy and the crystal deposits were evaluated by a semi-quantitative scoring method using computer software (ImageScoring). The results revealed that the rats of placebo group gained the least significant body weight; in contrast, the rats of WLS-fed groups could effectively reverse it. The placebo group exhibited lower levels of free calcium (p = 0.059) and significantly lower serum phosphorus (p = 0.015) in urine than WLS-fed rats. Histological findings of kidneys revealed tubular destruction, damage and inflammatory reactions in the EG-water rats. The crystal deposit scores dropped significantly in the WLS groups, from 1.40 to 0.46 in the low-dose group and from 1.40 to 0.45 in the high-dose group. Overall, WLS effectively inhibited the deposition of calcium oxalate (CaOx) crystal and lowered the incidence of stones in rats (p = 0.035). In conclusion, WLS significantly reduced the severity of calcium oxalate crystal deposits in rat kidneys, indicating that Wulingsan may be an effective antilithic herbal formula.     

Inhibitions of urinary oxidative stress and renal calcium level by an extract of Quercus salicina Blume/Quercus stenophylla Makino in a rat calcium oxalate urolithiasis model

Objectives:   To clarify the mechanism of Urocalun, an extract of Quercus salicina Blume /Quercus stenophylla Makino (QS), in the treatment of urolithiasis.
Methods:   Rat calcium oxalate urolithiasis was induced by oral administration of ethylene glycol and the vitamin D₃ analog alfa-calcidol for 14 days. QS extract was repeatedly given to rats. After the last administration, biochemistries in urine and plasma, renal calcium, and urinary malondialdehyde (an oxidative stress marker) were measured.
Results:   Ethylene glycol and alfa-calcidol treatment increased urinary malondialdehyde and renal calcium levels. This increase was significantly suppressed by the administration of QS extract, suggesting that the inhibition of renal calcium accumulation by QS extract is due to its antioxidative activity.
Conclusions:   These findings suggest that the antioxidative activity of QS extract plays a role in the prevention of stone formation and recurrence in urolithiasis.     

中医不同治法对绝经后骨质疏松症大鼠骨骼、骨骼肌SDF-1含量影响的比较研究

目的探究用中医滋补肾阴、温补肾阳、健脾、补肾健脾治法治疗绝经后骨质疏松症是否会引起骨骼、骨骼肌中SDF-1水平的变化,从而扩展中医防治骨质疏松症的现代医学机制。方法除正常组外,将去卵巢致骨质疏松症的大鼠随机分为模型组、补肾阴组、补肾阳组、健脾组、补肾健脾组和福善美组。采用酶联免疫吸附法检测各组大鼠血清ALP、TRACP及骨骼、骨骼肌中SDF-1的水平。结果模型组大鼠血清ALP和TRACP水平均比正常组显著升高(P<0.01);各治疗组均比模型组显著降低(P<0.01),以福善美组降低最为明显,其次为补肾健脾组。②模型组大鼠的骨骼和骨骼肌SDF-1水平均比正常组显著升高(P<0.01);与模型组相比,补肾阳组、福善美组大鼠骨组织SDF-1水平显著降低(P<0.01),健脾组、补肾阴组也降低(P<0.05),福善美组、健脾组大鼠的骨骼肌SDF-1水平显著降低(P<0.01)。结论骨质疏松症的发生与骨骼、骨骼肌中SDF-1水平的升高有关。②补肾阴、补肾阳、健脾和补肾健脾法可以减少绝经后骨质疏松症大鼠骨骼、骨骼肌中SDF-1的水平,从而对骨质疏松症起到一定的防治作用。     

维生素C对大鼠肾结石模型体内活性氧及成石的影响

目的　观察不同剂量维生素C(VitC)对大鼠肾结石模型体内活性氧 (ROS)的影响及VitC、ROS与肾结石形成的关系。　方法　用乙二醇诱导Wistar大鼠产生肾草酸钙结石。 30只大鼠分为正常组 ,成石组 ,治疗组 (分三个不同剂量 ,VitC 2 5、10 0、4 0 0mg·kg-1·d-1) ,喂养 15d。测定血和右肾组织中丙二醛 (MDA)、过氧化氢酶 (CAT)、超氧化物歧化酶 (SOD)、谷胱甘肽过氧化物酶(GSH Px)含量 ;左肾冰冻切片 ,偏光显微镜观察结晶情况。　结果　成石组血和组织中的MDA分别为 (43.89± 5 .10 )nmol/ml和 (6 .2 0± 2 .0 0 )nmol/gpr,较正常组增高 ,差别有显著性意义 (P <0 .0 1和P <0 .0 0 1) ,而抗氧化酶显著降低 (P <0 .0 1和P <0 .0 0 1)。VitC 4 0 0mg·kg-1·d-1治疗组血MDA(30 .80± 4 .6 9)nmol/ml,较成石组降低 (P <0 .0 5 ) ,与正常组比较差别无显著性意义 (P >0 .0 5 ) ,血SOD较成石组降低 (P <0 .0 5 ) ,血CAT、GSH Px较成石组升高 (P <0 .0 1) ;VitC 4 0 0mg·kg-1·d-1治疗组肾组织中MDA(11.96± 2 .4 4 )nmol/gpr ,较成石组升高 (P <0 .0 5 ) ,SOD较成石组升高 (P <0 .0 5 ) ,CAT、GSH Px较成石组有所降低。肾组织晶体形成与VitC剂量呈正相关 (r =0 .6 6 85 ,P <0 .0 1)。　结论　高草酸尿可使机体活性     

The effectiveness of Hedyotis diffusa Willd extract in a mouse model of experimental autoimmune prostatitis

Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) is a frustrating and often debilitating disease. Current studies have shown that Traditional Chinese Medicine (TCM) can improve patients’ quality of life and alleviate CP/CPPS symptoms. In this study, the efficacy of Hedyotis diffusa Willd aqueous extraction in experimental autoimmune prostatitis (EAP) mice models was revealed. The C57BL/6 mice were randomly assigned to three groups. Except for the control group, all other groups were subcutaneously injected with 0.2 ml emulsion of T2 peptide, on day 0 and day 14, for inducing EAP models. After the EAP modelling, oral saline was given to the model group, while the H. diffusa group was treated with aqueous extract of H. diffusa Willd. Micturition habits and withdrawal response frequencies were measured. Haematoxylin and eosin staining and immunohistochemistry were used to investigate inflammatory cell infiltration and TNF-α in the prostate tissue respectively. TNF-α levels in the serum were evaluated by ELISA. The H. diffusa Willd aqueous extraction considerably reduced the urine spots number and increased the pain threshold in H. diffusa group. H. diffusa group showed significantly reduced inflammatory lesion and inflammatory cell infiltration than the model group. The levels of TNF-α in H. diffusa group were considerably reduced.     

中药葛根对去卵巢大鼠骨代谢生化指标的影响

目的　研究中药葛根对去卵巢大鼠骨代谢生化指标的影响 ,探讨葛根治疗骨质疏松症的药理作用。方法　采用去卵巢大鼠模型 ,分A去势组、B假手术组、C去势服葛根组、D去势服西药组 (阳性对照组 ,程序治疗 ) ,去势 1个月后C、D组服药 50d ,放免法测定血清雌二醇 (E2 )、邻甲酚酞络合酮法测定尿钙 ,ELISA法测定尿脱氧吡啶啉 (Dpd) ,放免法测定血清骨钙素 (BGP)水平 ,组间进行比较。结果　E2 测定B、C、D组高于A组 (P <0 0 0 1 ) ,C、D组低于B组 (P <0 0 1 ,P <0 0 0 1 )。尿钙测定B、C、D组低于A组 (P <0 0 1 )。Dpd测定B、C、D组低于A组 (P <0 0 0 1 ) ,C、D组低于B组 (P <0 0 5 ,P <0 0 1 )。BGP测定B组低于A组 (P <0 0 1 ) ,C、D组高于A组 (P <0 0 1 ,P <0 0 5) ,同时高于B组(P <0 0 0 1 )。结论　中药葛根有增加E2 ,抑制骨吸收 ,促进骨形成 ,对骨质疏松症有治疗作用     

骨碎补总黄酮对去卵巢大鼠下颌骨显微结构及最大载荷的影响

目的应用Micro-CT和骨生物力学技术,探讨骨碎补总黄酮对去卵巢大鼠的下颌骨显微结构及最大载荷的影响。方法40只3月龄雌性SD大鼠,随机分为5组:假手术组(sham operation group,Sham)、去卵巢模型组(ovariectomized group,OVX)、骨碎补总黄酮高剂量组(high-dose drynaria total flavonoids group,GB-H)、骨碎补总黄酮低剂量组(low-dose drynaria total flavonoids group,GB-L)和戊酸雌二醇组(Estradiol Valerate group,EV),建模成功后连续给药12 w。实验结束后,取下颌骨进行显微CT扫描及三维重建,然后进行最大载荷测量。结果与Sham组相比,OVX组大鼠下颌骨微结构:骨密度、相对骨体积、骨小梁厚度、骨小梁数目明显减小(P0.05),骨表面积体积比、骨小梁间隙明显增高(P0.05);下颌骨的最大载荷明显减少(P0.05)。与OVX组相比,EV组大鼠下颌骨微结构获得良好修复,最大载荷也明显修复。骨碎补总黄酮低剂量组相对骨体积、骨小梁数目较OVX组显著升高(P0.05),骨小梁间隙显著减小(P0.05)。骨碎补总黄酮高剂量组疗效优于低剂量组,大鼠下颌骨的相对骨体积、骨表面积体积比、骨小梁间隙、骨小梁数目以及下颌骨骨密度均得到一定程度修复,下颌骨最大载荷也较OVX组显著增加(P0.05)。结论骨碎补总黄酮能够修复去卵巢大鼠下颌骨微结构,提高下颌骨骨密度和最大载荷,这将可能为颌骨骨质疏松的防治提供一种新的途径。     

Inhibitory effect of bikunin on calcium oxalate crystallization in vitro and urinary bikunin decrease in renal stone formers

Two proteins of 17 and 24 kDa, respectively, which were immunologically related to bikunin, were purified from urine of healthy men, using in the last step a trypsin CNBr-sepharose affinity column. These proteins strongly inhibited calcium oxalate (CaOx) crystallization in two in vitro models. In the first model, the presence of 8 μg/ml protein in a medium containing 0.76 mM CaCl₂ (with ⁴⁵Ca) and 0.76 mM ammonium oxalate inhibited the crystallization process by 80%, as estimated by supernatant radioactivity after 60 min of incubation. A similar inhibition was observed in the second turbidimetric model, where the CaOx crystallization kinetics were followed for 10 min at 620 nm in a medium containing 4 mM CaCl₂ and 0.5 mM Na₂Ox. These proteins were used as standard protein for the development of an enzyme-linked immunosorbent assay (ELISA) in urine. Mean (± SEM) urinary bikunin concentration in 18 healthy subjects was 5.01 ± 0.91 μg/ml. This was a concentration range of strong inhibitory activity in vitro. Bikunin values were nearly 50% lower (2.54 ± 0.42 μg/ml, P=0.007) in 31 CaOx renal stone formers (having weddelite crystals in their first morning urine) than in the healthy volunteers. A correlation was found between urinary bikunin and alpha-1 microglobulin concentrations in the control group (y=0.73x + 1.09, r ²=0.8) while no such correlation existed in the lithiasis group. In conclusion, bikunin exerts a strong inhibitory action of CaOx crystallization in vitro. Its involvement in urinary CaOx crystallization of stone formers is highly probable, based on the significant decrease in its urinary concentration in the majority of stone formers studied. Received: 16 December 1997 / Accepted: 23 June 1998     

左旋精氨酸对大鼠心脏移植物血管病变的抑制作用

目的　研究左旋精氨酸对大鼠心脏移植物血管病变的抑制作用及其机理。方法　采用大鼠异位心脏移植模型。对照组 :移植后不用左旋精氨酸 ;实验组 :移植后按 80 0mg·kg-1·d-1将左旋精氨酸加入饮水中。于移植后 2个月和 3个月检测各组的心脏移植物 ,血管病变评分和血浆一氧化氮含量。结果　移植后 2个月 ,实验组的移植物存活率为 90 .5 % ,显著高于对照组的 6 1.5 % (P <0 .0 5 )。移植后 2个月和 3个月 ,实验组血浆一氧化氮含量均显著高于对照组 ,分别为 ( 10 5 .37± 10 .6 6 ) μmol/Lvs( 6 8.5 4± 6 .83) μmol/L(P <0 .0 5 ) ,和 ( 10 4.5 3± 12 .31) μmol/Lvs ( 6 6 .32± 10 .5 4) μmol/L(P <0 .0 5 ) ;而对照组心脏移植物血管病变评分显著高于实验组 ,分别为 2 .4± 0 .7vs 1.1± 0 .6 (P <0 .0 5 ) ,和 3.0±0 .8vs 1.6± 0 .9(P <0 .0 5 )。实验组心脏移植物的冠状动脉内膜病变轻微 ,内皮和内弹力层基本保持完整 ,平滑肌细胞增殖不明显。结论　补充左旋精氨酸可改善心脏移植物血管病变 ,其机理与一氧化氮合成增加有关。一氧化氮具有保持内皮功能 ,抑制平滑肌细胞增殖的作用。