Effects of unclipping and converting enzyme inhibition on bilateral renal function in Goldblatt hypertensive rats

Effects of unclipping and converting enzyme inhibition on bilateral renal function in Goldblatt hypertensive rats. Previous studies have demonstrated that blockade of the renin-angiotensin system in two-kidney, one clip Goldblatt hypertensive rats induced arterial pressure associated reductions in the function of the renin rich, clipped kidney even though the renin-depleted, contralateral kidney exhibited enhanced renal hemodynamics and excretory function. This study was performed to evaluate the influence of inhibition of the activity of the renin-angiotensin system on the function of each kidney following the unclipping of the clipped kidney. Renin-angiotensin system blockade was accomplished by intravenous infusion of converting enzyme inhibitor (CEI, SQ 20881, 3 mg/hr · kg), either before (group 1, N = 15) or after (group 2, N = 16) removal of the clip. CEI infusion before unclipping decreased arterial blood pressure (BP), from 157 ± 3 to 124 ± 3mm Hg and led to increases in renal blood flow (RBF), GFR, urinary volume and sodium excretion in the nonclipped kidney. When the clip was still in place, renal function decreased in the clipped kidney during CEI infusion. Upon removal of the clip, there were immediate increases in RBF and GFR, and pronounced diuresis; natriuresis and kaliuresis ensued despite a further reduction of BP from 124 ± 3 to 110 ± 3mm Hg. In group 2, unclipping of the clipped kidney prior to administration of CEI reduced BP from 161 ± 4 to 118 ± 3mm Hg within 2hr. Nevertheless, RBF, GFR, urine flow, and sodium and potassium excretion rates increased in this newly undipped kidney. Subsequent infusion of CEI decreased BP further, but RBF, GFR, and urinary excretion rates of both kidneys increased significantly. These results suggest that hemodynamic and excretory function of both the nonclipped and clipped kidneys are influenced substantially by the renin-angiotensin system; however, this influence on the clipped kidney can be unmasked only after the clip has been removed.Effets de l'ablation du clip et de l'inhibition de l'enzyme de conversion sur la fonction rénale bilatérale chez des rats hypertendus selon Goldblatt. Les études antérieures ont démontré que le blocage du système rénine-angiotensine chez des rats hypertendus selon Goldblatt à deux reins et un clip entrainait des réductions de la fonction du rein riche en rénine clippé, en rapport avec la pression artérielle, bien que le rein contralatéral, déplété en rénine, ait une augmentation de l'hémodynamique et de la fonction excrétoire rénales. Cette étude a été entreprise afin d'évaluer l'influence de l'inhibition de l'activité du système rénine-angiotensine sur la fonction de chaque rein après ablation du clip du rein clippé. Le blocage du système rénine-angiotensine a été effectué par perfusion intra-veineuse de l'inhibiteur de l'enzyme de conversion (CEI, SQ 20881, 3 mg/hr · kg) soit avant (groupe 1, N = 15) soit après (groupe 2, N = 16) ablation du clip. La perfusion de CEI avant l'ablation du clip a abaissé la pression artérielle (BP) de 157 ± 3 à 124 ± 3mm Hg, et a augmenté le flux sanguin (RBF), le GFR, le volume urinaires et l'excrétion sodée du rein non clippé. Lorsque le clip était encore en place, la fonction rénale diminuait du côté du rein clippé pendant la perfusion de CEI. Lors de l'ablation du clip, il y avait des augmentations immédiates du RBF et de GFR et une diurèse; une natriurèse et une kaliurèse prononcées se produisaient malgré une réduction supplémentaire de la BP de 124 ± 3 à 110 ± 3mm Hg. Dans le groupe 2, l'ablation du clip avant l'administration de CEI a réduit la BP du rein clippé de 161 ± 4 à 118 ± 3mm Hg en 2hr. Cependant, le RBF, le GFR, le débit urinaire, et l'excrétion de sodium et de potassium se sont élevés dans ce rein dont le clip a été récemment enlevé. La perfusion ultérieure de CEI diminuait BP plus mais RBF, GFR, et les excrétions urinaires des deux reins ont augmenté significativement. Ces résultats suggèrent que les fonctions hémodynamique et excrétoire des reins clippés et non-clippés sont substantiellement influencées par le système rénine-angiotensine; cependant, cette influence sur le rein clippé ne peut être démasquée qu'après ablation du clip

INFLUENCE OF CONSTITUTION OF HYBRID FERROCENYL ALKANETHIOLS SELF-ASSEMBLED MONOLAYERS TO INTERFACIAL CHARACTERISTICS ON GOLD SURFACE

[[abstract]]The interfacial characteristics of self-assembled monolayer (SAM), that are applied in miniaturized sensor design, were strongly influenced by the SAM constitution. The electrochemical and interfacial characteristics of hybrid SAMs that constituted with ferrocenyl octanethiol (FcC8SH) and unsubstituted octanethiol (C8) or 2-mercaptopyrimidine (2-MPD) were investigated in this study. The peaks of anodic oxidation were observed at around 0.49 V (vs. Ag/AgCl) in the FcC8SH/C8 hybrid SAM. However, the oxidation potentials descended from 0.42–0.38 V as the molar fraction of FcC8SH was decreased from 0.8–0.2 in the FcC8SH/2-MPD hybrid SAM. On the other hand, the interfacial hydrophilicity of FcC8SH/2-MPD hybrid SAM was measured to be higher than the FcC8SH/C8 hybrid SAM due to the random arrangement of SAM caused by the shape of 2-MPD. Then, the surface roughness of hybrid SAM and chain length of ferrocenyl alkanethiols were all considered to be the parameters of interfacial characteristics. In summary, doping of 2-MPD in SAMs might reduce the rigidity of ferrocenyl alkanethiol SAMs and increase the interfacial hydrophilicity. This result will be useful in the development of the low power consumption portable bioanalytical system. And a miniaturized bioanalytical system based on ferrocenyl SAMs would be developed in the future.[[notice]]補正完畢[[journaltype]]國外[[incitationindex]]SCI[[incitationindex]]EI[[booktype]]紙本[[countrycodes]]SG

Pre-Treatment with Ten-Minute Carbon Dioxide Inhalation Prevents Lipopolysaccharide-Induced Lung Injury in Mice via Down-Regulation of Toll-Like Receptor 4 Expression

Various animal studies have shown beneficial effects of hypercapnia in lung injury. However, in patients with acute respiratory distress syndrome (ARDS), there is controversial information regarding the effect of hypercapnia on outcomes. The duration of carbon dioxide inhalation may be the key to the protective effect of hypercapnia. We investigated the effect of pre-treatment with inhaled carbon dioxide on lipopolysaccharide (LPS)-induced lung injury in mice. C57BL/6 mice were randomly divided into a control group or an LPS group. Each LPS group received intratracheal LPS (2 mg/kg); the LPS groups were exposed to hypercapnia (5% carbon dioxide) for 10 min or 60 min before LPS. Bronchoalveolar lavage fluid (BALF) and lung tissues were collected to evaluate the degree of lung injury. LPS significantly increased the ratio of lung weight to body weight; concentrations of BALF protein, tumor necrosis factor-α, and CXCL2; protein carbonyls; neutrophil infiltration; and lung injury score. LPS induced the degradation of the inhibitor of nuclear factor-κB-α (IκB-α) and nuclear translocation of NF-κB. LPS increased the surface protein expression of toll-like receptor 4 (TLR4). Pre-treatment with inhaled carbon dioxide for 10 min, but not for 60 min, inhibited LPS-induced pulmonary edema, inflammation, oxidative stress, lung injury, and TLR4 surface expression, and, accordingly, reduced NF-κB signaling. In summary, our data demonstrated that pre-treatment with 10-min carbon dioxide inhalation can ameliorate LPS-induced lung injury. The protective effect may be associated with down-regulation of the surface expression of TLR4 in the lungs