Cerebral Blood Flow Threshold and Regional Heterogeneity of Heat Shock Protein 72 Induction Following Transient Forebrain Ischemia in Rats

Heat shock proteins (HSPs) induced by brain ischemia may play an important role in neuroprotection from neuronal degeneration. In this study, we examined the cerebral blood flow (CBF) threshold to produce regional differences in HSP72 induction after transient forebrain ischemia in spontaneously hypertensive rats (SHRs). Female SHRs were subjected to 20 min of cerebral ischemia induced by bilateral carotid artery occlusion. The CBF was measured by laser Doppler flowmetry. At forty-eight hours after cerebral ischemia and reperfusion, the rats were decapitated and the brains were removed. Specific areas (hippocampal CA1, CA2-3, dentate gyrus, dorsolateral and ventromedial striatum, and parietal cortex) were thereafter dissected from the brain. The amounts of HSP72 in these samples were determined using Western blot analysis. In the hippocampus, HSP72 was induced when the CBF decreased to less than 18–25% of the resting level. The mean values of HSP72 produced in the CA1 area, CA2-3 area, and the dentate gyrus following ischemia and reperfusion treatment were 4.44 ± 1.43 (±SD) ng/g prtein, 3.51 ± 0.72 ng/g protein and 3.77 ± 1.05 ng/g protein, respectively. In the parietal cortex, the amount of HSP72 induction was less pronounced (2.55 ± 0.40 ng/g protein), while HSP72 was hardly detected at all in the striatum, even under conditions of very severe CBF reduction and reperfusion. We demonstrated the existence of both a CBF threshold (i.e., approximately 20% of the resting level) for HSP72 induction and regional heterogeneity for the induction of HSP72 protein.     

光合细菌PSB-1菌株的分离鉴定及其生物学特性的研究

光合细菌菌株ＰＳＢ－１,初步定为Ｒｈｏｄｏｐｓｅｕｄｏｍｏｎａｓ ａｃｉｄｏｐｈｉｌａ,系由生活污水中分离获得,革兰氏反应阴性,菌体大小为：长０．２５～０．４５μｍ,宽０．８～２．０μｍ,单个细胞卵圆至球形,出芽生殖,未观察到鞭毛。菌落为玫瑰红色,菌体液体培养物为深红色,菌体中含有丰富的细菌叶绿素ａ和类胡萝卜素,光合内膜结构为片层状,位于质膜之下并与质膜平行。ＰＳＢ－１在黑暗和光照中均能生长,但在黑暗中培养时菌液颜色不变,能利用多种有机碳源和氮源,ＤＮＡ中Ｇ＋Ｃ摩尔分数为６５．７％。     

替米沙坦及吡哆胺对自发性高血压大鼠脑组织氧化应激的影响

目的:探讨替米沙坦及吡哆胺对自发性高血压大鼠脑组织氧化应激的影响。方法:自发性高血压大鼠24只随机分为4组(n=6):高血压对照组(HC组);替米沙坦组(T组);吡哆胺组(P组);联合治疗组(TP组)。同龄WKY大鼠作为正常对照组(NC组)。药物干预16周,测定各组脑组织中丙二醛(MDA)含量、超氧化物歧化酶(SOD)活性及烟酰胺腺嘌呤二核苷酸磷酸(NADPH)氧化酶p47phox mRNA表达。结果:与NC组比较,HC组脑组织中MDA含量明显升高、SOD活性明显减低(P<0.05);与HC组比较T组、P组、TP组MDA含量明显减低,SOD活性明显升高(P<0.05);与NC组比较HC组(NADPH)氧化酶p47phox mRNA表达显著上调(P<0.01);与HC组比较T组、TP组NADPH氧化酶p47phox mRNA表达明显下调(P<0.01);HC组与P组比较NADPH氧化酶p47phox mRNA表达无统计学差异(P>0.05)。结论:自发性高血压大鼠脑组织处于氧化应激状态,替米沙坦及吡哆胺可抑制自发性高血压大鼠脑组织的氧化应激水平,联合治疗并不优于替米沙坦单药治疗。     

Novel Angiotensin I-Converting Enzyme Inhibitory Peptides Found in a Thermolysin-Treated Elastin with Antihypertensive Activity

Angiotensin I-converting enzyme (ACE) inhibitory activity was generated from elastin and collagen by hydrolyzing with thermolysin. The IC₅₀ value of 531.6 µg/mL for ACE inhibition by the elastin hydrolysate was five times less than 2885.1 µg/mL by the collagen hydrolysate. We confirmed the antihypertensive activity of the elastin hydrolysate in vivo by feeding spontaneously hypertensive rats (male) on a diet containing 1% of the elastin hydrolysate for 9 weeks. About 4 week later, the systolic blood pressure of the rats in the elastin hydrolysate group had become significantly lower than that of the control group. We identified novel ACE inhibitory peptides, VGHyp, VVPG and VYPGG, in the elastin hydrolysate by using a protein sequencer and quadrupole linear ion trap (QIT)-LC/MS/MS. VYPGG had the highest IC₅₀ value of 244 µM against ACE and may have potential use as a functional food.     

正常大鼠植入高血压大鼠肾脏后动脉血压的变化

本实验对12周龄的自发性高血压大鼠(spontaneouslyhypertensiverat,SHR)及其对照组WistarKyoto(WKY)大鼠进行了肾脏移植的研究,并观察受肾移植大鼠动脉血压的变化以及免疫抑制剂对动脉血压的影响。用尾套法对接受同窝另一同胞WKY大鼠肾脏移植且存活5周的6只WKY大鼠(A组)及接受SHR肾脏移植且存活5周的6只WKY大鼠(B组)的尾动脉收缩压进行检测,移植前A、B两组受肾移植大鼠的尾动脉收缩压分别为180±093和183±068kPa,无统计学显著差异(P>005);移植后3、4、5周时,B组大鼠的尾动脉收缩压显著高于A组大鼠,移植后5周时,A,B两组大鼠的收缩压分别为190±071和230±069kPa(P<0001);所用剂量的免疫抑制剂CsA对双侧肾脏完整以及右侧肾脏切除的SHR、WKY大鼠的动脉血压无显著影响。以上结果表明,SHR的肾脏在高血压的形成中可能起重要作用     

SHR与WKY大鼠肾脏组织基因表达差异分析

为了观察SHR与WKY大鼠肾脏组织的基因表达的差异,用T11G、AP6引物对12周龄的SHR与WKY大鼠肾脏mRNA进行了差异显示,得到了一条在SHR大鼠肾脏组织中高表达的差异显示条带,进一步分析证明这一差异显示条带含有170 bp,与GenBank 收录的已知的核苷酸序列的同源性低于80%,可能为未知基因的cDNA片段,并定位于SHR大鼠的肾小管上皮细胞内.     

Isolation and Characterization of a Hydrogen Sulfide-Removing Bacterium,Pseudomonas sp. Strain DO-1

Five microbial strains that removed hydrogen sulfide (H₂S) or methylmercaptan (CH₃SH) gas were newly isolated from soil samples. Strain DO-1, one of the isolates, was identified as a member of Pseudomonas sp., and it’s immobilized cells removed 1 or 10 ppm of H₂S gas within 2 hours. When strain DO-1 was cultured aerobically in a flask containing nutrient broth medium, the deodorizing activity increased, depending on the growth of the culture, and the maximum activity was obtained after 48 hours. Even though the immobilized cells were stored at 4 or 25°C in sealed bottles for 6 months, the deodorizing activity remained. Throughout this study, strain DO-1 removed H₂ S gas without preliminary feeding or exposure to sulfur com-pounds as growth substrates or inducers. These characteristics are advantageous for the deodorization of the malodorous gases surrounding us in daily life.     

自发性高血压大鼠心肌和血管组织牛磺酸的转运障碍

在自发性高血压大鼠（SHR）的心肌和主动脉血管组织上观察牛磺酸（taurine)转运和牛磺酸转运体（taurine transporter,TAUT) mRNA 的改变,结果显示,与对照组WKY大鼠相比,SHR组血浆牛磺酸水平和牛磺酸释放量增加,而心肌和血管组织牛磺酸水平和TAUT mRNA含量均降低,牛磺酸最大转运速率（Vmax)分别低24％和35％（P＜0．05）,米氏常数（Km)值分别高16％和39％（P＜0．05）,这些结果提示,SHR的心肌和血管组织牛磺酸转运障碍可能与TAUT活性和亲和力降低及TAUT基因水平的下调有关。     

Increased mRNA expression of cardiac renin-angiotensin system and collagen synthesis in spontaneously hypertensive rats

Hypertensive cardiac hypertrophy is associated with the accumulation of collagen in the myocardial interstitium. Previous studies have demonstrated that this myocardial fibrosis accounts for impaired myocardial stiffness and ventricular dysfunction. Although cardiac fibroblasts are responsible for the synthesis of fibrillar collagen, the factors that regulate collagen synthesis in cardiac fibroblasts are not fully understood. We investigated the effects of angiotensin II on cardiac collagen synthesis in cardiac fibroblasts. Cardiac fibroblasts of 10 week old spontaneously hypertensive rats and age-matched Wistar-Kyoto rats were prepared and maintained in culture medium supplemented with 10% fetal calf serum. The expression of mRNA of the renin-angiotensin system (renin, angiotensinogen, angiotensin converting enzyme) was determined by using a ribonuclease protection assay. Basal collagen synthesis in cardiac fibroblasts from spontaneously hypertensive rats was 1.6 fold greater than that in the cell of Wistar-Kyoto rats. Angiotensin II stimulated collagen synthesis in cardiac fibroblasts in a dose-dependent manner. The responsiveness of collagen production to angiotensin II was significantly enhanced in cardiac fibroblasts from spontaneously hypertensive rats (100 nM angiotensin II resulted in 185 ± 18% increase above basal levels, 185 ± 18 versus 128 ± 19% in Wistar-Kyoto rats p < 0.01). This effect was receptor-specific, because it was blocked by the competitive inhibitor saralasin and MK 954. These results indicate that collagen production was enhanced in cardiac fibroblasts from spontaneously hypertensive rats, that angiotensin II had a stimulatory effect on collagen synthesis in cardiac fibroblasts, and that cardiac fibroblasts from spontaneously hypertensive rats were hyper-responsive to stimulation by angiotensin II.Level of angiotensin and renin mRNA expressed in ventricles, and angiotensinogen mRNA expressed in fibroblasts from SHR were higher than those from WKY.These findings suggest that the cardiac renin-angiotensin system may play an important role in collagen accumulation in hypertensive cardiac hypertrophy.     

Antihypertensive Effect of an Extract of Passiflora edulis Rind in Spontaneously Hypertensive Rats

Orally administered methanol extract of Passiflora edulis rind (10 mg/kg or 50 mg/kg) or luteolin (50 mg/kg), which is one of consistent polyphenols of the extract, significantly lowered systolic blood pressure in spontaneously hypertensive rats (SHRs). Quantitative analysis by liquid chromatography tandem mass spectrometry (LC-MS/MS) showed that the extract contained 20 μg/g dry weight of luteolin and 41 μg/g dry weight of luteolin-6-C-glucoside. It also contained γ-aminobutyric acid (GABA, 2.4 mg/g dry weight by LC-MS/MS or 4.4 mg/g dry weight by amino acid analysis) which has been reported to be an antihypertensive material. Since the extract contained a relatively high concentration of GABA, the antihypertensive effect of the extract in SHRs might be due mostly to the GABA-induced antihypertensive effect and partially to the vasodilatory effect of polyphenols including luteolin.     

Orally administered collagen peptide protects against UVB-induced skin aging through the absorption of dipeptide forms,Gly-Pro and Pro-Hyp

Collagen hydrolysate is a well-known nutritional supplement for the improvement of healthy skin. Here, collagen peptide NS (CPNS) from fish scale was prepared, and its physicochemical properties were investigated. Gly-Pro was revealed as a representative low molecular weight peptide of CPNS, by performing prep-HPLC and LC-MS/MS. CPNS treatment attenuated matrix metalloproteinase-1 production and increased the synthesis of type 1 procollagen in HDF cells. After orally administering CPNS to rats, the plasma concentrations of Gly-Pro and Pro-Hyp increased dramatically. To examine the protective effects of CPNS against ultraviolet B (UVB)-induced photoaging in vivo, the dorsal skins of hairless mice were exposed to UVB and supplemented with CPNS for 12 weeks. The CPNS consumption significantly attenuated UVB-induced wrinkle formation, transepidermal water loss, and epidermis thickness, and increased skin hydration. Collectively, these results suggest that bioactive peptides of CPNS, Gly-Pro and Pro-Hyp, exert beneficial effects on skin health.     

自发性高血压大鼠多组织炎症状态

高血压是一种慢性血管性疾病,易累及肾、肝、心、脑等组织,引起脑卒中和心、肾损害等并发症.本研究对高血压时肾、肝、心、脑等组织的炎症状态进行了观察.实验采用自发性高血压大鼠(spontaneously hypertensive rat,SHR)和正常血压的Wistar-Kyoto(WKY)大鼠,用RT-PCR和Western blot法观察肾、肝、心、脑等组织炎症相关因子IL-1p、TNFα、ICAM-1、iNOS、C/EBPδ和PPARγ的基因表达;紫外分光光度法观察蛋白质羰基化水平和FRAP法检测组织总抗氧化能力.结果显示(1)SHR组织炎症相关因子表达较对照WKY增强,除IL-1βmRNA在肝和脑的增加不明显外,其余均有显著性差异(P＜0.05);(2)SHR和WKY大鼠肾、心、脑蛋白质羰基化水平(nmol/mg蛋白)分别为8.93±1.08和2.27±0.43、2.23±0.23和0.17±0.02、13.42±1.10和5.72±1.01,SHR明显增加(P＜0.05);而肝脏蛋白质羰基化水平无明显变化;(3)SHR肾、肝、心、脑总抗氧化能力水平显著低于WKY大鼠(P＜0.05).以上结果表明,SHR多个组织(肾、肝、心和脑)均存在炎症因子被诱导和氧化应激反应等明显的炎症状态,提示炎症可能在高血压及其并发症的病理改变中起重要作用.     

Effects of Various Polyunsaturated Fatty Acids on Blood Cholesterol and Eicosanoids in Rats

The hypocholesterolemic efficacy of various polyunsaturated fatty acids was compared in rats given cholesterol-enriched diets with (0.004%) or without indomethacin, the cyclooxygenase inhibitor. Evening primrose oil (EPO, linoleic+ γ-linolenic), safflower oil (SFO, linoleic) or soybean oil (SBO, linoleic + α-linolenic) were added to diets at the 10% level. The serum cholesterol level of the EPO group was consistently lower than the other groups and after 3 weeks, it was significantly different from the SFO group without indomethacin and the SBO group with indomethacin. In rats fed EPO, the aorta tended to produce more prostacyclin whereas the concentration of plasma thromboxane B₂ was much lower than in rats fed SFO or SBO. The effects of indomethacin on these eicosanoids were less evident in rats fed EPO. Thus, in addition to the hypocholesterolemic action of β-linolenic acid (GLA) in preference to linoleic and possibly α-linolenic acid, GLA appears to cultivate an environment suitable for the prevention of carbiovascular disease even in the presence of excess cholesterol in the diet.     

Strain Differences in SA Gene Expression in Brain and Kidney of Normotensive and Hypertensive Rats

SUMMARY 1. In situ hybridization done using a ³⁵S-cRNA probe was carried out to obtain information on the expressions of the SA gene in brains and kidneys of the spontaneously hypertensive rat (SHR) strain obtained from the Izumo colony (/Izm) and from Charles River Laboratories (/Crj).2. In the brain, SA mRNA expression was most abundantly observed in epithelial cells of the choroid plexus. High to moderate levels was present on neurons of the CA1–CA4 pyramidal cell layer and the dentate gyrus of the hippocampus and the cerebellar Purkinje cell layer. The solitary tract nucleus and the dorsal motor nucleus of the vagus expressed the SA gene at very low levels. An increase in the expression was noted in the choroid plexus of WKY/Crj; there was no difference, however, in expression levels of other brain areas between WKY/Izm, SHR/Izm, and SHRSP/Izm, and between WKY/Crj and SHR/Crj.3. In the kidney, expression signals of SA mRNA were observed in renal medullary rays and focal cortex of WKY/Izm, SHR/Izm, SHRSP/Izm, and SHR/Crj, whereas mRNA expression in the WKY/Crj kidney was observed in medullary rays and outer strips of the outer medulla. Microscopically, hybridization signals were predominant in the proximal tubules.4. Expression densities decreased only in the kidney of WKY/Crj in 4-and 8-week-old rats, but not in the WKY/Izm kidney, compared with findings in SHR and SHRSP kidneys. These observations are in good agreement with data from Northern blot analysis.5. The SA gene expressions in the brain and the kidney seem not to relate to states of elevated blood pressure, but rather to strain differences. Abundant expressions in the brain and the kidney may mean that the SA gene plays a role in the water–electrolyte transport system. It is noteworthy that there are neuronal expressions of the SA gene in hippocampal pyramidal cells and cerebellar Purkinje cells.     

Identification and Subcellular Distribution of Carotenoids in the Aerobic Photosynthetic Bacterium, Pseudomonas radiora Strain MD-1

The carotenoid compositions in the aerobic methylotrophic photosyntheticbacterium, Pseudomonas radiora (Methylobacterium radiotolerans)strain MD-1, were investigated. Carotenoids bound to the BChl-proteincomplex were identified as spirilloxanthin, anhydrorhodovibrinand rhodovibrin, which have been generally found in purple photosyntheticbacteria. The ratio of BChl a to carotenoid in the BChl-proteincomplex was about 2 to 1. The transfer of excitation energyfrom carotenoids to BChl in the BChl-protein complex was observedalthough its efficiency was as low as that in the purple bacterialcomplexes which have spirilloxanthin as the major carotenoidcomponent. By contrast, carotenoic acids were found as majorforms of carotenoids in the cells, and most of them were notbound to the BChl-protein complex. These carotenoic acids werealso found as the major carotenoids in other methylotrophs thathave been characterized as aerobic photosynthetic bacteria. (Received November 28, 1994; Accepted April 21, 1995)     

Potent hypotensive activity of 1-O-hexadecyl-2-O-acetyl-sn-glycero-3-phosphocholine in spontaneously hypertensive rat

Chemically synthesized 1-O-hexadecyl-2-O-acetyl-$\text{sn}$-glycero-3-phosphocholine possessed the most potent hypotensive activity compared with bradykinin, prostagrandin E₂ and I₂ when 5 nano moles/kg body weight of each drug were administered intravenously in spontaneously hypertensive rat. The potency and the duration of hypotensive activity of 1-O-hexadecyl-2-O-acetyl-$\text{sn}$-glycero-3-phosphocholine were dose dependent. Exogenous norepinephrine or angiotensin II showed pressor activity during the hypotensive action of 1-O-hexadecyl-2-O-acetyl-$\text{sn}$-glycero-3-phosphocholine, but did not disturb the hypotensive pattern of this ether lipid. These may suggest that 1-O-alkyl-2-O-acetyl-$\text{sn}$-glycero-3-phosphocholine plays an important role for the regulation of blood pressure.     

心钠素表达细胞移植降低高血压大鼠的血压和增加其尿量

为探讨心钠素基因转移治疗高血压和慢性心肾功能衰竭等慢性疾病的潜力,首先利用逆转录病毒载体获得可表达和分泌人心钠素的遗传工程细胞,然后将这种细胞植于自发性高血压大鼠SHR的皮下。结果发现,人心钠素遗传工程细胞的移植可使动物血浆中的心钠素浓度在移植后第7天时明显升高。在整个实验期间,虽然实验组动物的血压会随个体发育而逐渐升高,但在实验开始后的42 d内却始终明显低于空载体组,其中第14天血压的差异高达33 mm Hg。在实验开始后的第14天和第21天,实验组动物的尿量也明显增加。以上结果说明,人心钠素遗传工程细胞的皮下移植可明显抑制SHR大鼠血压的上升趋势和改善其泌尿功能,提示该方法具有治疗高血压和慢性心肾功能衰竭等慢性疾病的潜力。     

自发性高血压大鼠和Wistar-Kyoto大鼠心血管组织肾上腺髓质素和肾上腺髓质素原N-末端20肽的水平

本工作观察了自发性高血压大鼠 (SHRs)和Wistar kyoto (WKY)大鼠心肌和主动脉肾上腺髓质素 (a drenomedullin ,ADM)和肾上腺髓质素原N 末端 2 0肽 (proadrenomedullinNterminal 2 0peptide ,PAMP)的水平。以放射免疫分析方法测定血浆、心肌和主动脉ADM含量。用竞争性定量逆转录多聚酶链式反应 (RT PCR)方法测定心肌和主动脉ProADMmRNA含量。结果发现 ,SHRs心肌和主动脉ProADMmRNA水平分别比WKY大鼠高 66 7%和 73 % (均P <0 0 1)。SHRs血浆、心肌和主动脉ADM ir含量分别较WKY大鼠高 2 9%、76 7%和 79% (均P <0 0 1)。SHRs血浆、心肌和主动脉PAMP ir水平分别较WKY大鼠高 42 5 % (P <0 0 1)、47 2 % (P <0 0 1)和 2 7 3 % (P <0 0 5 )。另外 ,SHRs的ADM和PAMP的比值较WKY大鼠明显增高 (心肌和主动脉分别为 2 0± 0 2 5vs 1 64± 0 3和 2 2± 0 18vs 1 5 6± 0 2 8)。结果提示 ,SHRs心肌和主动脉ProADM基因表达上调 ,ADM和PAMP水平升高 ,但二者升高的比例不一致。SHRs的ADM和PAMP升高不一致的病理生理意义有待进一步研究     

一株吡嘧磺隆降解菌S8-1的分离鉴定及生物学特性

以多年连续施用吡嘧磺隆除草剂的水稻试验田泥土为材料,采用富集培养、平板反复划线分离方法,分离到一株能以吡嘧磺隆为唯一碳源和能源生长的光合细菌(Photosynthetic Bacterium,简称PSB),命名为S8-1。通过菌落形态特征观察、菌体形态学观察、活细胞吸收光谱特征、培养特性、生理生化特性及16SrRNA同源性序列分析(GenBank登录号:GQ180069)等试验,初步鉴定该菌为红假单胞菌属(Rhodopseudomonas sp.)。利用高效液相色谱(HPLC)测定了菌株S8-1的降解性能,得出该菌降解吡嘧磺隆的最佳条件为:pH值为7.0-7.5,温度为30°C-35°C;在30°C与pH7.0的光合细菌培养基中培养7d,对100mg/L的吡嘧磺隆降解率为52.07%;并且该菌对浓度高达800mg/L的吡嘧磺隆仍保持降解活性,外加发酵提取物能够明显提高菌体的生长及其降解效率,显示了该菌在高浓度农药废水处理及土壤农药残留生物修复方面潜在的开发价值。