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Hyperpolarized 13C magnetic resonance evaluation of renal ischemia reperfusion injury in a murine model 下载免费PDF全文
Aisha True‐Yasaki Jeremy W. Gordon Cornelius von Morze Justin Delos Santos David M. Wilson Robert Raffai Patrick M. Cowley Anthony J. Baker John Kurhanewicz David H. Lovett Zhen Jane Wang 《NMR in biomedicine》2017,30(10)
Acute kidney injury (AKI) is a major risk factor for the development of chronic kidney disease (CKD). Persistent oxidative stress and mitochondrial dysfunction are implicated across diverse forms of AKI and in the transition to CKD. In this study, we applied hyperpolarized (HP) 13C dehydroascorbate (DHA) and 13C pyruvate magnetic resonance spectroscopy (MRS) to investigate the renal redox capacity and mitochondrial pyruvate dehydrogenase (PDH) activity, respectively, in a murine model of AKI at baseline and 7 days after unilateral ischemia reperfusion injury (IRI). Compared with the contralateral sham‐operated kidneys, the kidneys subjected to IRI showed a significant decrease in the HP 13C vitamin C/(vitamin C + DHA) ratio, consistent with a decrease in redox capacity. The kidneys subjected to IRI also showed a significant decrease in the HP 13C bicarbonate/pyruvate ratio, consistent with impaired PDH activity. The IRI kidneys showed a significantly higher HP 13C lactate/pyruvate ratio at day 7 compared with baseline, although the 13C lactate/pyruvate ratio was not significantly different between the IRI and contralateral sham‐operated kidneys at day 7. Arterial spin labeling magnetic resonance imaging (MRI) demonstrated significantly reduced perfusion in the IRI kidneys. Renal tissue analysis showed corresponding increased reactive oxygen species (ROS) and reduced PDH activity in the IRI kidneys. Our results show the feasibility of HP 13C MRS for the non‐invasive assessment of oxidative stress and mitochondrial PDH activity following renal IRI. 相似文献
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Growth hormone responses to acute resistance exercise with vascular restriction in young and old men
Todd M. Manini Joshua F. Yarrow Thomas W. Buford Brian C. Clark Christine F. Conover Stephen E. Borst 《Growth hormone & IGF research》2012,22(5):167-172
ObjectiveResistance exercise (RE) stimulates growth hormone (GH) secretion in a load-dependent manner, with heavier loads producing larger GH responses. However, new research demonstrates that low-load RE performed with blood flow restriction (BFR) produces potent GH responses that are similar to or exceed those produced following high-load RE. We hypothesized that low-load RE with vascular restriction would attenuate the known age-related reduction in GH response to RE.DesignIn a randomized crossover design, ten young (28 ± 7.8 years) and ten older (67.4 ± 4.6 years) men performed bilateral knee extension RE with low-load [20% of one-repetition maximum (1RM)] with BFR and high-load (80% 1RM) without BFR. GH and lactate were measured every 10 minutes throughout a 150-minute testing session (30 minutes prior to and 120 minutes following completion of the exercise); IGF-I was measured at baseline and 60 minutes post-exercise.ResultsArea under the GH curve indicated that both age groups responded similarly to each exercise condition. However, young men had a significantly greater maximal GH response to low-load RE with BFR than the high-load condition without BFR. Additionally, younger men had greater maximal GH concentrations to low-load RE with BFR than older men (p = 0.02). The GH responses were marginally correlated to lactate concentration (r = 0.13, p = 0.002) and IGF-I levels were unchanged with RE.ConclusionsGH responses to low-load RE with vascular restriction are slightly higher than high-load RE without vascular restriction in young men. However, low-load RE with vascular restriction did not attenuate the known age-related reduction in GH response with exercise. These data suggest that while low-load RE with vascular restriction is as effective for inducing a GH response than traditionally-based high-load RE, there is a more potent response in young men. 相似文献
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Cornelius Anna Pilger Daniel Riechardt Aline Reitemeyer Emanuel Rübsam Anne Winterhalter Sibylle Maier Anna-Karina B. 《Albrecht von Graefes Archiv fur klinische und experimentelle Ophthalmologie》2022,260(3):957-965
Graefe's Archive for Clinical and Experimental Ophthalmology - To compare the blood flow situation in primary open-angle glaucoma (POAG) and pseudoexfoliation glaucoma (PXG) using optical... 相似文献
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