Šio darbo tikslas ištirti išemijos/reperfuzijos poveikį žiurkės inkstų mitochondrijų funkcijoms. Pagrindiniai darbo uždaviniai: 1) įvertinti išemijos (20, 40, 60 minučių) in vitro poveikį inkstų mitochondrijų kvėpavimo funkcijoms; 2) įvertinti išemijos (60 minučių) ir reperfuzijos (30 minučių) in vivo poveikį inkstų mitochondrijų kvėpavimo funkcijoms; 3) ištirti išemijos poveikį inkstų mitochondrijų kvėpavimo grandinės I komplekso aktyvumui. Išemijos poveikio žiurkės inkstų mitochondrijų funkcijų tyrimui buvo pasirinkti du eksperimentiniai modeliai, t.y. in vitro ir in vivo modelis. Mitochondrijas išskyrėme diferencinio centrifugavimo būdu, baltymą nustatėme biureto metodu. Išskirtų mitochondrijų kvėpavimo greitį vertinome poliarografiniu metodu. I komplekso aktyvumą nustatėme spektrofotometriniu būdu. Rezultatai parodė, kad mitochondrijų pažaida išryškėja labai anksti - jau po 20 minučių, t.y. slopinamas maksimalus (ADP stimuliuotas) mitochondrijų kvėpavimo greitis tiek oksiduojant glutamatą/malatą, tiek sukcinatą. Ilginant išemijos trukmę, mitochondrijų pažaida didėjo. Išorinės mitochondrijų membranos pažaida taip pat didėjo ilginant išemijos trukmę. Tiek išemija (60 minučių), tiek reperfuzija (30 minučių) slopina mitochondrijų kvėpavimo greitį trečioje metabolinėje būsenoje. 60 minučių išemija/30 minučių reperfuzija nepadidino mitochondrijų vidinės membranos pralaidumo. Rezultatai rodo, jog išemijos poveikyje (60 minučių) mitochondrijos pasižeidžia labiau nei... [toliau žr. visą tekstą] / The aim of this work is to explore the effect of ischemia/reperfusion on rat kidney mitochondrial function. The main objectives of this work are to: 1) evaluate the effect of ischemia (20, 40, 60 minutes) in vitro on kidney mitochondrial function; 2) evaluate the effect of ischemia (60 minutes) and reperfusion (30 minutes) in vivo on kidney mitochondrial function; 2) explore the effect of ischemia/reperfusion on kidney mitochondrial respiratory chain complex I activity. We chose two experimental models of ischemia for investigation of its effects on rat kidney mitochondrial functions, i.e. in vitro and in vivo models. The mitochondria were isolated by a differential centrifugation method, while the protein was determined using biuret method. Mitochondrial respiration rate was measured polarographically. Complex I activity was evaluated spectrophotometrically. The results showed that mitochondrial damage become apparent very early - after 20 minutes, i.e. the maximal (ADP- stimulated) mitochondrial respiration rate decreased with both, glutamate/malate and succinate. It is obvious that by increasing the duration of ischemia, the mitochondrial damage increased. The damage of mitochondrial outer membrane increased by increasing the duration of ischemia. We found that both, ischemia (60 minutes) and reperfusion (30 minutes) decreased the mitochondrial State 3 respiration rate. 60 minutes ischemia/30 minutes reperfusion had no effect on mitochondrial inner membrane permeability... [to full text]

国立情報学研究所で電子化したコンテンツを使用している。

Reperfusion injury may mediate renal dysfunction following ischaemia. A murine model was developed to investigate the role of the tissue factor-thrombin-protease activated receptor pathway in renal ischaemia reperfusion injury (IRI). In this model, mice received 25 minutes of ischaemia and subsequent periods of reperfusion. C57BL6, protease activated receptor-1 (PAR-1) knockout mice, and tissue factor (TF) deficient mice were used. Following 24 hours IRI, PAR-1 deficiency resulted in protection against severe renal failure compared to the C57BL6 mice (creatinine, 118.2 ?? 6.3 vs 203 ?? 12 ??mol/l, p&lt0.001). This was confirmed by lesser tubular injury. By 48 hours IRI, this resulted in a survival benefit (survival, 87.5% vs 0%, p&lt0.001). Treatment of C57BL6 mice with hirudin, a specific thrombin inhibitor, offered renoprotection at 24 hours IRI (creatinine, 107 ?? 10 ??mol/l, p&lt0.001), leading to a 60% survival rate at 48 hours IRI (p&lt0.001). TF deficient mice expressing less than 1% of C57BL6 mouse TF were also protected (creatinine, 113.6 ?? 7 ??mol/l, p&lt0.001), with a survival benefit of 75% (p&lt0.001). The PAR-1 knockout, hirudin treated C57BL6 and TF deficient mice had reduced myeloperoxidase activity and tissue neutrophil counts compared to the C57BL6 mice, along with reduced KC and MIP-2 chemokine mRNA and protein expression. Hirudin treatment of PAR-1 knockout mice had no additional benefit over PAR-1 absence alone, suggesting no further contribution by activation of other protease activated receptors (creatinine at 24 hours IRI, 106.5 ?? 10.5 ??mol/l, p&gt0.05). Furthermore, immunofluoresence staining for fibrin(ogen) showed no difference between C57BL6 and PAR-1 knockout mice, suggesting no major contribution by fibrin in this model. Renal IRI resulted in increased levels of TF mRNA expression in the C57BL6, PAR-1 knockout, and hirudin treated C57BL6 mice compared to normal controls, suggesting that TF mRNA expression was upregulated in this model. This resulted in increased TF functional activity in the C57BL6 and PAR-1 knockout mice, but TF activity was negligible in hirudin treated C57BL6 and TF deficient mice. The data therefore suggests that the TF-thrombin cascade contributes to renal IRI by signalling via PAR-1 that then regulates chemokine gene expression and subsequent neutrophil recruitment.

Diss. (sammanfattning) Göteborg : Göteborgs universitet, 2007. / Härtill 4 uppsatser.

Thèse (D. en biochimie)--Université du Québec à Montréal, 2005. / En tête du titre: Université du Québec à Montréal. Bibliogr.: f. 182-208. Publié aussi en version électronique.

Thesis (M. Phil.)--University of Hong Kong, 2007. / Also available in print.

Thesis (M. Phil.)--University of Hong Kong, 2008. / Also available in print.

Diss. (sammanfattning) Göteborg : Göteborgs universitet , 2007. / Härtill 5 uppsatser.

Diss. (sammanfattning) Stockholm : Karol. inst., 2003. / Härtill 5 uppsatser.

Thesis (M. Med. Sc.)--University of Hong Kong, 200.