1
|
Wu X, Tang W, Tang D, Hu Y, Zhang N, Dai S, Pan Y, Li J, Guan H, Meng J, Zhao X, Xiao X, Yin J. Two a posteriori dietary patterns are associated with risks of hyperuricemia among adults in less-developed multiethnic regions in Southwest China. Nutr Res 2023; 110:96-107. [PMID: 36696716 DOI: 10.1016/j.nutres.2022.12.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 12/20/2022] [Accepted: 12/27/2022] [Indexed: 01/01/2023]
Abstract
Diet is a major determinant of hyperuricemia, but little is known about the association between diet and hyperuricemia in less-developed multiethnic regions (LMERs). This study aimed to assess the hypothesis that dietary patterns (including 2 a-priori and 3 a posteriori dietary patterns) are associated with hyperuricemia in LMERs. The 2 a priori dietary patterns were the Dietary Approaches to Stop Hypertension (DASH) and the alternative Mediterranean diet (aMED). We derived 3 a posteriori dietary patterns from the China Multi-Ethnic Cohort study by principal component factor analysis. Given that those dietary patterns had high geographic discrimination, they were named the Sichuan Basin (economically developed industrial region), Yunnan-Guizhou Plateau (agricultural region), and Qinghai-Tibet Plateau (nomadic region) dietary pattern, respectively. We performed a logistic regression model to investigate associations between dietary patterns and hyperuricemia with potential confounders identified by the directed acyclic graph. Comparing the highest with the lowest quintiles, the Sichuan Basin dietary pattern was positively associated with hyperuricemia, whereas the Yunnan-Guizhou Plateau dietary pattern showed an inverse association with hyperuricemia. For the Qinghai-Tibet Plateau dietary pattern, DASH, or aMED, our results did not show a significant association with hyperuricemia. The results were robust among stratified analyses and different analyzing strategies. The dietary patterns showed great diversity in Southwest China. Both DASH and aMED, which many studies widely recommended, did not show expected beneficial effects on preventing hyperuricemia. However, the plant-based protein dietary pattern in the Yunnan-Guizhou Plateau showed a beneficial association with the risk of hyperuricemia, which can provide insights for dietary guidance in LMERs.
Collapse
Affiliation(s)
- Xinyu Wu
- West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, China
| | - Wenge Tang
- Chongqing Municipal Center for Disease Control and Prevention, Chongqing, China
| | - Dan Tang
- West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, China
| | - Yifan Hu
- West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, China
| | - Ning Zhang
- West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, China
| | - Suyao Dai
- West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, China
| | - Yongyue Pan
- School of Medicine, Tibet University, Lhasa, China
| | - Jingzhong Li
- Tibet Center for Disease Control and Prevention, Lhasa, China
| | - Han Guan
- School of Public Health, the Key Laboratory of Environmental Pollution Monitoring and Disease Control, Ministry of Education, Guizhou Medical University, Guiyang, China
| | - Jiantong Meng
- Chengdu Center for Disease Control and Prevention, Chengdu, China
| | - Xing Zhao
- West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, China
| | - Xiong Xiao
- West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, China.
| | - Jianzhong Yin
- School of Public Health, Kunming Medical University, Baoshan College of Traditional Chinese Medicine, Kunming, China.
| |
Collapse
|
2
|
Zhu J, Duan Y, Duo D, Yang J, Bai X, Liu G, Wang Q, Wang X, Qu N, Zhou Y, Li X. High-altitude Hypoxia Influences the Activities of the Drug-Metabolizing Enzyme CYP3A1 and the Pharmacokinetics of Four Cardiovascular System Drugs. Pharmaceuticals (Basel) 2022; 15:ph15101303. [PMID: 36297415 PMCID: PMC9612038 DOI: 10.3390/ph15101303] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 10/11/2022] [Accepted: 10/18/2022] [Indexed: 11/16/2022] Open
Abstract
(1) Background: High-altitude hypoxia has been shown to affect the pharmacokinetic properties of drugs. Although there is a high incidence of cardiovascular disease among individuals living in high-altitude areas, studies on the effect of high-altitude hypoxia on the pharmacokinetic properties of cardiovascular drugs are limited. (2) Methods: The aim of this study was to evaluate the pharmacokinetics of nifedipine, bosentan, simvastatin, sildenafil, and their respective main metabolites, dehydronifedipine, hydroxybosentan, simvastatin hydroxy acid, and N-desmethyl sildenafil, in rats exposed to high-altitude hypoxia. Additionally, the protein and mRNA expression of cytochrome P450 3A1 (CYP3A1), a drug-metabolizing enzyme, were examined. (3) Results: There were significant changes in the pharmacokinetic properties of the drugs in rats exposed to high-altitude hypoxia, as evidenced by an increase in the area under the curve (AUC) and the half-life (t1/2z) and a decrease in total plasma clearance (CLz/F). However, most of these changes were reversed when the rats returned to a normoxic environment. Additionally, there was a significant decrease in CYP3A1 expression in rats exposed to high-altitude hypoxia at both the protein and mRNA levels. (4) Conclusions: High-altitude hypoxia suppressed the metabolism of the drugs, indicating that the pharmacokinetics of the drugs should be re-examined, and the optimal dose should be reassessed in patients living in high-altitude areas.
Collapse
Affiliation(s)
- Junbo Zhu
- Research Center for High Altitude Medicine, Qinghai University Medical College, Xining 810000, China
- State Key Laboratory of Plateau Ecology and Agriculture, Qinghai University, Xining 810000, China
| | - Yabin Duan
- Department of Clinical Pharmacy, Qinghai University Affiliated Hospital, Xining 810000, China
| | - Delong Duo
- Research Center for High Altitude Medicine, Qinghai University Medical College, Xining 810000, China
| | - Jianxin Yang
- Research Center for High Altitude Medicine, Qinghai University Medical College, Xining 810000, China
| | - Xue Bai
- Research Center for High Altitude Medicine, Qinghai University Medical College, Xining 810000, China
| | - Guiqin Liu
- Research Center for High Altitude Medicine, Qinghai University Medical College, Xining 810000, China
| | - Qian Wang
- Research Center for High Altitude Medicine, Qinghai University Medical College, Xining 810000, China
| | - Xuejun Wang
- Department of Anesthesiology, Red Cross Hospital of Qinghai, Xining 810000, China
| | - Ning Qu
- Department of Anesthesiology, Qinghai Hospital of Traditional Chinese Medicine, Xining 810000, China
| | - Yang Zhou
- State Key Laboratory of Functions and Applications of Medicinal Plants, Guizhou Provincial Key Laboratory of Pharmaceutics, Guizhou Medical University, Guiyang 550004, China
- Correspondence: (Y.Z.); (X.L.)
| | - Xiangyang Li
- Research Center for High Altitude Medicine, Qinghai University Medical College, Xining 810000, China
- State Key Laboratory of Plateau Ecology and Agriculture, Qinghai University, Xining 810000, China
- Correspondence: (Y.Z.); (X.L.)
| |
Collapse
|
3
|
Peng H, Feng D, Wang Y, Dong Z, Chen Q, Zhang L, Luo R, Chen J, Wang A, Ma S. Effect of Oral Vitamin C Supplementation on High-Altitude Hyperuricemia in Young Men Initially Migrating to High Altitude: A Pilot Study. High Alt Med Biol 2018; 19:373-381. [PMID: 30358417 DOI: 10.1089/ham.2018.0058] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
OBJECTIVE Clinical studies have shown that oral vitamin C supplementation can reduce serum uric acid levels in multiple populations and may also improve acute mountain sickness. However, it is unclear whether this protocol can improve high-altitude hyperuricemia. Therefore, we aimed to evaluate the role of vitamin C supplementation on high-altitude hyperuricemia. METHODS A preliminary prospective control study was performed in 2015. Young male army recruits (n = 66), who had recently arrived on the Tibetan Plateau for the first time, were recruited for study I. Subjects were assigned to either the vitamin C group, who took an oral daily dose of 500 mg vitamin C for 1 month, or the blank control group, who had no intervention. The levels of serum uric acid, serum creatinine, and blood urea nitrogen were monitored at baseline and at the end of 1 month. In a second study II in 2016 (n = 120), the effect of 500 mg/d vitamin C on high-altitude hyperuricemia was compared with 75 IU/d of vitamin E. RESULTS In study I, the level of serum uric acid at 1 month was significantly higher than at baseline (436.1 ± 79.3 μmol/L vs. 358.0 ± 79.8 μmol/L, p < 0.001) and the prevalence of hyperuricemia was also significantly higher (63.6% [95% confidence interval, CI: 52.0%-75.2%] vs. 19.7% [95% CI: 10.1%-29.3%], p < 0.001). Both the level of serum uric acid (411.5 ± 74.2 μmol/L vs. 460.8 ± 54.8 μmol/L, p = 0.003) and the prevalence of hyperuricemia (48.5% [95% CI: 31.4%-65.6%] vs. 78.8% [95% CI: 64.9%-92.7%], p = 0.020) were significantly lower in the vitamin C group than in the blank control group. In study II, the levels of serum uric acid and the frequency of hyperuricemia also increased over 1 month and were similar in the vitamin C and the vitamin E groups at both baseline and 1 month (p > 0.05). The change in serum uric acid was positively correlated with both the changes in serum creatinine (r = 0.599, p < 0.001) and blood urea nitrogen (r = 0.207, p = 0.005). CONCLUSIONS These findings indicate that healthy young men develop an increase in serum uric acid within a month of moving from low to high altitude. Oral vitamin C supplementation can safely reduce this increase at a low cost.
Collapse
Affiliation(s)
- Hui Peng
- 1 Department of Infectious Disease, Kunming General Hospital of Chengdu Military Command, Kunming, China.,2 Department of Postgraduate, Kunming Medical University, Kunming, China
| | - Dongfang Feng
- 3 Laboratory Department, Tibet Military Region General Hospital, Tibet, China
| | - Yingkai Wang
- 4 Medical Administration Division, Tibet Military Region General Hospital, Tibet, China
| | - Zixi Dong
- 5 Medical Administration Division, Kunming General Hospital of Chengdu Military Region, Kunming, China
| | - Qing Chen
- 1 Department of Infectious Disease, Kunming General Hospital of Chengdu Military Command, Kunming, China.,2 Department of Postgraduate, Kunming Medical University, Kunming, China
| | - Lihong Zhang
- 1 Department of Infectious Disease, Kunming General Hospital of Chengdu Military Command, Kunming, China
| | - Ruigang Luo
- 6 Medical Team, Tibet Military Region 77649 Unit, Tibet, China
| | - Jinsong Chen
- 6 Medical Team, Tibet Military Region 77649 Unit, Tibet, China
| | - Anjun Wang
- 6 Medical Team, Tibet Military Region 77649 Unit, Tibet, China
| | - Shiwu Ma
- 1 Department of Infectious Disease, Kunming General Hospital of Chengdu Military Command, Kunming, China.,7 State Key Laboratory of Organ Failure Research, Department of Infectious Diseases, Nanfang Hospital, Southern Medical University, Guangzhou, China
| |
Collapse
|
4
|
Zhang JB, Wang L, Chen J, Wang ZY, Cao M, Yie SM, Yang H, Yao XQ, Zeng Y, Yang YC, Xie CB, Zhao TQ. Frequency of Polycythemia and Other Abnormalities in a Tibetan Herdsmen Population Residing in the Kham Area of Sichuan Province, China. Wilderness Environ Med 2018; 29:18-28. [PMID: 29338990 DOI: 10.1016/j.wem.2017.09.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2017] [Revised: 09/19/2017] [Accepted: 09/20/2017] [Indexed: 01/02/2023]
Affiliation(s)
- Jian-Bo Zhang
- Core Laboratory, (Drs Zhang, Chen, Z Wang, Cao, and Yie).
| | - Lin Wang
- Health Management Center, (Drs L Wang and H Yang, Mr Yao, and Ms Zeng)
| | - Jie Chen
- Core Laboratory, (Drs Zhang, Chen, Z Wang, Cao, and Yie)
| | - Zhi-Ying Wang
- Core Laboratory, (Drs Zhang, Chen, Z Wang, Cao, and Yie)
| | - Mei Cao
- Core Laboratory, (Drs Zhang, Chen, Z Wang, Cao, and Yie)
| | - Shang-Mian Yie
- Core Laboratory, (Drs Zhang, Chen, Z Wang, Cao, and Yie)
| | - Hua Yang
- Health Management Center, (Drs L Wang and H Yang, Mr Yao, and Ms Zeng)
| | - Xiao-Qin Yao
- Health Management Center, (Drs L Wang and H Yang, Mr Yao, and Ms Zeng)
| | - Yi Zeng
- Health Management Center, (Drs L Wang and H Yang, Mr Yao, and Ms Zeng)
| | - Yong-Chang Yang
- Clinical Laboratory, (Drs L Wang and H Yang, Mr Yao, and Ms Zeng); Sichuan Provincial People's Hospital, Chengdu, China
| | - Chun-Bao Xie
- Clinical Laboratory, (Drs L Wang and H Yang, Mr Yao, and Ms Zeng); Sichuan Provincial People's Hospital, Chengdu, China
| | - Tai-Qiang Zhao
- Clinical Laboratory, (Drs L Wang and H Yang, Mr Yao, and Ms Zeng); Sichuan Provincial People's Hospital, Chengdu, China
| |
Collapse
|
5
|
Shimamoto N. [A pathophysiological role of cytochrome p450 involved in production of reactive oxygen species]. YAKUGAKU ZASSHI 2014; 133:435-50. [PMID: 23546588 DOI: 10.1248/yakushi.12-00263] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Dysregulation of the production of reactive oxygen species (ROS) determines cellular function. Cytochrome P450s (CYPs) regulates ROS production and contributes to the process of cell death. This review summarizes our recent findings, focusing on the involvement of CYPs in pathophysiology induced by ROS. 1. Quinone toxicity in hepatocytes: CYPs require electrons supplied from NADPH-cytochrome P450 reductase (NPR) during the process of metabolism. NPR also provides electrons to quinone compounds, which compete with CYPs over electrons. Inhibition of CYPs shifts NPR's electron flow more to quinones, which accelerates the redox cycle to enhance ROS production and quinone toxicity. 2. Myocardial ischemia-reperfusion injury: Reperfusion of blood flow after coronary artery occlusion induces cell damage, as evident by the extension of myocardial infarct size and caspase-independent cell apoptosis. CYP2C6 appears to be a source for ROS production, since sulfaphenazole, a selective inhibitor of CYP2C6, reduces this damage. ROS produced by CYP2C6 during the reperfusion causes translational activation of Noxa and BimEL, as well as the suppression of caspase activation, resulting in caspase-independent apoptosis. 3. Primary hepatocyte apoptosis: Inhibition of catalase and glutathione peroxidase increases intracellular ROS and elicits caspase-independent hepatocyte apoptosis. SKF-525A, a pan-CYP inhibitor, suppresses these ROS increases and hepatocyte apoptosis. Increased ROS activates ERK and AP-1 by inhibition of tyrosine phosphatase, and inhibits BimEL degradation by proteasome. These results in the accumulation of mitochondrial BimEL, which then induces the release of cytochrome c and endonuclease G (EndoG). Increased ROS also keeps caspases inactivated. As a result, EndoG executes nucleosomal DNA fragmentation.
Collapse
Affiliation(s)
- Norio Shimamoto
- Laboratory of Pharmacology, Faculty of Pharmaceutical Sciences at Kagawa, Tokushima Bunri University, Kagawa 769-2193, Japan
| |
Collapse
|
6
|
Hurtado A, Escudero E, Pando J, Sharma S, Johnson RJ. Cardiovascular and renal effects of chronic exposure to high altitude. Nephrol Dial Transplant 2013; 27 Suppl 4:iv11-6. [PMID: 23258804 DOI: 10.1093/ndt/gfs427] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Over 140 million people live at high altitude, defined as living at an altitude of 2400 m or more above sea level. Subjects living under these conditions are continuously living under hypoxic conditions and, depending on the population, various adaptations have developed. Interestingly, subjects living chronically at high altitude appear to have a decreased frequency of obesity, diabetes and coronary artery disease. However, these benefits on health are balanced by the frequent development of systemic and pulmonary hypertension. Recently, it has been recognized that subjects living at high altitude are at risk for developing high-altitude renal syndrome (HARS), which is a syndrome consisting of polycythemia, hyperuricemia, systemic hypertension and microalbuminuria, but with preserved glomerular filtration rate. More studies should be performed to characterize the mechanisms and etiology of HARS; as such studies may be of benefit not only to the high-altitude population, but also to better understanding of the renal consequences of acute and chronic hypoxia.
Collapse
Affiliation(s)
- Abdias Hurtado
- Division of Nephrology, Hospital Arzobispo Loayza, Cayetano Heredia University, Lima, Peru.
| | | | | | | | | |
Collapse
|
7
|
Raedschelders K, Ansley DM, Chen DDY. The cellular and molecular origin of reactive oxygen species generation during myocardial ischemia and reperfusion. Pharmacol Ther 2011; 133:230-55. [PMID: 22138603 DOI: 10.1016/j.pharmthera.2011.11.004] [Citation(s) in RCA: 256] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2011] [Accepted: 11/04/2011] [Indexed: 02/07/2023]
Abstract
Myocardial ischemia-reperfusion injury is an important cause of impaired heart function in the early postoperative period subsequent to cardiac surgery. Reactive oxygen species (ROS) generation increases during both ischemia and reperfusion and it plays a central role in the pathophysiology of intraoperative myocardial injury. Unfortunately, the cellular source of these ROS during ischemia and reperfusion is often poorly defined. Similarly, individual ROS members tend to be grouped together as free radicals with a uniform reactivity towards biomolecules and with deleterious effects collectively ascribed under the vague umbrella of oxidative stress. This review aims to clarify the identity, origin, and progression of ROS during myocardial ischemia and reperfusion. Additionally, this review aims to describe the biochemical reactions and cellular processes that are initiated by specific ROS that work in concert to ultimately yield the clinical manifestations of myocardial ischemia-reperfusion. Lastly, this review provides an overview of several key cardioprotective strategies that target myocardial ischemia-reperfusion injury from the perspective of ROS generation. This overview is illustrated with example clinical studies that have attempted to translate these strategies to reduce the severity of ischemia-reperfusion injury during coronary artery bypass grafting surgery.
Collapse
Affiliation(s)
- Koen Raedschelders
- Department of Anesthesiology, Pharmacology and Therapeutics, Faculty of Medicine. The University of British Columbia, Vancouver, BC, Canada.
| | | | | |
Collapse
|
8
|
Arestegui AH, Fuquay R, Sirota J, Swenson ER, Schoene RB, Jefferson JA, Chen W, Yu XQ, Kelly JP, Johnson RJ, Escudero E. High Altitude Renal Syndrome (HARS). J Am Soc Nephrol 2011; 22:1963-8. [PMID: 21566053 DOI: 10.1681/asn.2010121316] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
|
9
|
de Jong JW, Schoemaker RG, de Jonge R, Bernocchi P, Keijzer E, Harrison R, Sharma HS, Ceconi C. Enhanced expression and activity of xanthine oxidoreductase in the failing heart. J Mol Cell Cardiol 2000; 32:2083-9. [PMID: 11040111 DOI: 10.1006/jmcc.2000.1240] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The molecular basis for heart failure is unknown, but oxidative stress is associated with the pathogenesis of the disease. We tested the hypothesis that the activity of xanthine oxidoreductase (XOR), a free-radical generating enzyme, increases in hypertrophied and failing heart. We studied XOR in two rat models: (1) The monocrotaline-induced right ventricular hypertrophy and failure model; (2) coronary artery ligation induced heart failure, with left ventricular failure and compensatory right ventricular hypertrophy at different stages at 3 and 8 weeks post-infarction, respectively. XOR activity was measured at 30 degrees C and the reaction products were analysed by HPLC. In both models XOR activity in hypertrophic and control ventricles was similar. In the monocrotaline model, the hearts showed enhanced XOR activity in the failing right ventricle (65+/-5 mU/g w/w), as compared to that in the unaffected left ventricle (47+/-3 mU/g P<0.05, n=6-7). In the coronary ligation model, XOR activities did not differ at 3 and 8 weeks. In the infarcted left ventricle, XOR activity increased from 29.4+/-1.4 mU/g (n=6) in sham-operated rats, to 48+/-3 and 80+/-6 mU/g (n=8 P<0.05 v sham) in the viable and infarcted parts of failing rat hearts, respectively. With affinity-purified polyclonal antibody, XOR was localized in CD68+ inflammatory cells of which the number increased more in the failing than in sham-operated hearts. Our results show that the expression of functional XOR is elevated in failing but not in hypertrophic ventricles, suggesting its potential role in the transition from cardiac hypertrophy into failure.
Collapse
Affiliation(s)
- J W de Jong
- Thoraxcenter, Erasmus University, Rotterdam, The Netherlands.
| | | | | | | | | | | | | | | |
Collapse
|
10
|
Pinson A, Tirosh R. Reversible and irreversible damage in reoxygenated 'ischemic' ventricular myocytes in culture. Mol Cell Biochem 1996; 160-161:137-41. [PMID: 8901467 DOI: 10.1007/bf00240043] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The LDH release pattern from cardiomyocytes under 'ischemia-like' conditions shows two phases. In the initial slow phase, reoxygenation immediately stops further enzyme release. Accelerated LDH release, which occurs concomitantly with Iysosomal enzyme release, characterizes the second phase of 'ischemia.' Reoxygenation at this stage does not put a stop to further enzyme release. Reoxygenation during the first phase of 'ischemia' rapidly restored ATP level, while in the second phase, ATP levels remained low even after 6 h of reoxygenation. This study as well as previous data seem to suggest that irreversible cellular damage leading to cell death, occurs by synergistic action of many effectors, each of which does not necessarily cause irreversible damage.
Collapse
Affiliation(s)
- A Pinson
- Laboratory for Myocardial Research, Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | | |
Collapse
|
11
|
Tavenier M, Skladanowski AC, De Abreu RA, de Jong JW. Kinetics of adenylate metabolism in human and rat myocardium. BIOCHIMICA ET BIOPHYSICA ACTA 1995; 1244:351-6. [PMID: 7599155 DOI: 10.1016/0304-4165(95)98595-c] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Pathways producing and converting adenosine have hardly been investigated in human heart, contrasting work in other species. We compared the kinetics of enzymes associated with purine degradation and salvage in human and rat heart cytoplasm assaying for adenosine deaminase, nucleoside phosphorylase, xanthine oxidoreductase, AMP deaminase, AMP- and IMP-specific 5'-nucleotidases, adenosine kinase and hypoxanthine guanine phosphoribosyltransferase (HGPRT). Xanthine oxidoreductase was not detectable in human heart. The Km-values of the AMP-catabolizing enzymes were 2-5 times higher in human heart; the substrate affinity of the other enzymes was in the same order of magnitude in both species. The maximal activity (Vmax) of adenosine kinase was the same in both species, but HGPRT in man was only 12% of that in the rat. For human heart the Vmax-values of adenosine deaminase, nucleoside phosphorylase, AMP- and IMP-specific 5'-nucleotidases, and AMP deaminase were 25-50% of those for rat heart. We conclude that human heart is less geared to purine catabolism than rat heart as is evident from the lower activities of the catabolic enzymes. Maintenance of the nucleotide pool may thus play a more important role in human heart.
Collapse
Affiliation(s)
- M Tavenier
- Cardiochemical Laboratory, Thoraxcenter, Erasmus University Rotterdam, Netherlands
| | | | | | | |
Collapse
|
12
|
Lazzarino G, Raatikainen P, Nuutinen M, Nissinen J, Tavazzi B, Di Pierro D, Giardina B, Peuhkurinen K. Myocardial release of malondialdehyde and purine compounds during coronary bypass surgery. Circulation 1994; 90:291-7. [PMID: 8026011 DOI: 10.1161/01.cir.90.1.291] [Citation(s) in RCA: 84] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
BACKGROUND Free radicals and lipid peroxidation have been suggested to play an important role in the pathophysiology of myocardial reperfusion injury. The purpose of the present study was to monitor myocardial malondialdehyde (MDA) production as an index of lipid peroxidation during ischemia-reperfusion sequences in patients undergoing elective coronary bypass grafting. There has been a lot of debate on the role of xanthine oxidase as a potential superoxide anion generator and thus lipid peroxidation in human myocardium. To evaluate the activity of xanthine oxidase pathway, we measured the changes in the transcardiac concentration differences in adenosine, inosine, hypoxanthine, xanthine, and uric acid. METHODS AND RESULTS The coronary sinus-aortic root differences (CS-Ao) of MDA, oxypurines, and nucleosides were measured by a recently developed ion-pairing high-performance liquid chromatographic (HPLC) method. Fifteen patients were included in the study, and 13 of them demonstrated a more than 10-fold increase in net myocardial production of MDA on intermittent reperfusion during the aortic cross-clamp period. In 2 patients, MDA was not detectable in any of the CS or Ao samples. Before aortic cross-clamping, the CS-Ao concentration differences in adenosine, inosine, hypoxanthine, xanthine, and uric acid were 0.59 +/- 0.19, 0.23 +/- 0.05, 0.89 +/- 0.36, 0.58 +/- 0.32, and 11.4 +/- 4.9 mumol/L, respectively. After aortic cross-clamping, the sum of the transcardiac differences of these compounds increased up to 2.8-fold and then gradually decreased after declamping of the aorta. There was a weak positive correlation between transcardiac concentration differences of MDA and xanthine plus uric acid (r = .48, P < .01). The postoperative functional recovery or leakage of cardiac enzymes was not affected by the level of MDA net release during the aortic cross-clamp period, however. CONCLUSIONS We conclude that myocardial lipid peroxidation, estimated as MDA formation, is common during intermittent ischemia-reperfusion sequences in coronary bypass surgery, although some patients may be better protected. Xanthine oxidase appears to be operative in human myocardium, and free radicals generated in this reaction might also be involved in the observed lipid peroxidation process. Increased degradation of myocardial adenine nucleotides and concomitant lipid peroxidation may play a specific role in the development of reperfusion injury. In this study, however, more extensive lipid peroxidation was not associated with impaired functional recovery.
Collapse
Affiliation(s)
- G Lazzarino
- Department of Experimental Medicine and Biochemical Sciences, II University of Rome Tor Vergata, Italy
| | | | | | | | | | | | | | | |
Collapse
|
13
|
Janssen M, Tavenier M, Koster JF, de Jong JW. In vitro and ex vivo xanthine oxidoreductase activity in rat and guinea-pig hearts using hypoxanthine or xanthine as substrate. BIOCHIMICA ET BIOPHYSICA ACTA 1993; 1156:307-12. [PMID: 8461322 DOI: 10.1016/0304-4165(93)90048-d] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Through oxyradical formation xanthine oxidoreductase (XOD) could play a role in the etiology of cardiac damage. Its measurement poses problems, due to little substrate specificity, self-inactivation and endogenous inhibitors. Perfusion of guinea-pig hearts with hypoxanthine gave rise to only little xanthine release; in contrast rat hearts showed vivid xanthine production. Therefore, xanthine breakdown was hypothesized to exceed its formation in guinea-pig hearts. The kinetics of both substrates for XOD in cardiac homogenates were therefore compared with those obtained in perfused hearts. Oxypurine contents and effluent catabolites were determined by HPLC. Regardless of substrate, Vmax values in homogenates were about 38 and 13 mU/g for rat and guinea-pig heart, respectively. Km values were in the 3-5 microM range; therefore the hypothesis concerning the low xanthine release in guinea-pig hearts must be rejected. Activities in hearts perfused with hypoxanthine (50 microM) were 40 and 18 mU/g for rat and guinea pig, respectively; perfusion with xanthine produced < 50% of the activities observed with hypoxanthine (p < 0.002). Intracellular xanthine concentration, estimated from sorbitol distribution space and myocardial xanthine content was negative in both species, contrasting intracellular hypoxanthine levels, which approached extracellular concentrations. This disparate distribution indicates that hypoxanthine transport across the cell membrane far exceeds that of xanthine. Consequently, hypoxanthine is preferable to xanthine as substrate in perfused hearts to estimate XOD activity in situ.
Collapse
Affiliation(s)
- M Janssen
- Cardiochemical Laboratory, Erasmus University Rotterdam, The Netherlands
| | | | | | | |
Collapse
|
14
|
Tabayashi K, Suzuki Y, Nagamine S, Ito Y, Sekino Y, Mohri H. A clinical trial of allopurinol (Zyloric) for myocardial protection. J Thorac Cardiovasc Surg 1991. [DOI: 10.1016/s0022-5223(19)36703-0] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
15
|
The isolated neonatal rat-cardiomyocyte used in an in vitro model for 'ischemia'. I. A morphological study. BIOCHIMICA ET BIOPHYSICA ACTA 1991; 1091:270-7. [PMID: 2001410 DOI: 10.1016/0167-4889(91)90189-5] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Cultured heart cells have been recently shown to be useful for analysing states of oxygen- and volume-restrictions, conditions that are known to simulate anoxia and ischemia at the cellular level. In the present study, we examined the ultrastructural damage caused to cultured neonatal rat heart cells when they were subjected to simulated ischemia by volume restricted anoxia ('ischemia') in an in vitro system. Both thin-sectioning and freeze-fracturing electron microscopy revealed a mitochondrial reorganization after 30 min of 'ischemia', whereas multilamellar structures could be detected inside the mitochondria after another 30 min. At this time-point, changes were also observed regarding the organization of the sarcolemma. In addition to a slight aggregation of the intramembranous particles (IMP's) we found an extensive extrusion of particle-free multilamellar membrane-structures, possibly due to a loss of the sarcolemma/cytoskeleton-interaction. These morphological changes are comparable to those previously observed in in vivo and Langendorff studies and the results of the present study therefore underline the usefulness of this recently introduced model for ischemia.
Collapse
|
16
|
Zoref-Shani E, Bromberg Y, Shirin C, Sidi Y, Sperling O. Hypoxanthine and inosine metabolism in cultured rat cardiomyocytes. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1991; 309A:321-5. [PMID: 1789235 DOI: 10.1007/978-1-4899-2638-8_73] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- E Zoref-Shani
- Department of Chemical Pathology, Sackler School of Medicine, Tel Aviv University, Israel
| | | | | | | | | |
Collapse
|
17
|
Bernauer W. Post-ischemic release of nucleosides and oxypurines in isolated rat hearts. Possible involvement of ventricular fibrillation. Basic Res Cardiol 1991; 86:1-10. [PMID: 2021384 DOI: 10.1007/bf02193866] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
In isolated perfused rat hearts global ischemia for 2, 5, and 15 min was produced. Depending on the duration of the ischemia, postischemic reperfusion led to the release of adenosine and its catabolites, and to more or less severe ventricular tachyarrhythmias. When ventricular fibrillation occurred, a highly significant increase in the purine release was observed compared with non-fibrillating hearts. Prevention of fibrillation by antiarrhythmic drugs decreased the purine release in a highly significant way. After only 2 min of ischemia, reperfusion did not lead to ventricular fibrillation. Electrical induction of fibrillation during the reperfusion in these hearts provoked the release of very high amounts of the purine compounds. A similar effect of electrically-induced fibrillation was also obtained in hearts without a previous ischemic period. The findings suggest that ventricular fibrillation is able to induce the release of purine derivatives from the heart.
Collapse
Affiliation(s)
- W Bernauer
- Department of Pharmacology, University of Freiburg, FRG
| |
Collapse
|
18
|
de Jong JW, van der Meer P, Nieukoop AS, Huizer T, Stroeve RJ, Bos E. Xanthine oxidoreductase activity in perfused hearts of various species, including humans. Circ Res 1990; 67:770-3. [PMID: 2397579 DOI: 10.1161/01.res.67.3.770] [Citation(s) in RCA: 80] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Oxygen free radicals generated by xanthine oxidase have been implicated in cardiac damage. The activity of xanthine oxidase/reductase in adult rat heart is considerable. Its assay gives controversial results for other species, for example, rabbits and humans. Therefore, we perfused isolated hearts of various species, including explanted human hearts, to measure the conversion of exogenous hypoxanthine to xanthine and urate. We assayed these purines with high-performance liquid chromatography. The apparent xanthine oxidoreductase activities, calculated as release of xanthine plus 2x urate, were (milliunits per gram wet weight, mean +/- SEM) mice 33 +/- 3 (n = 5), rats 28.5 +/- 1.4 (n = 9), guinea pigs 14.4 +/- 1.0 (n = 5), rabbits 0.59 +/- 0.09 (n = 5), pigs less than 0.1 (n = 6), humans 0.31 +/- 0.04 (n = 7), and cows 3.7 +/- 0.8 (n = 4). In rabbit heart the conversion of hypoxanthine to xanthine was slow, and that of xanthine to urate was even slower. On the other hand, guinea pig and human heart released little xanthine, indicating that xanthine breakdown exceeds its formation. We conclude that isolated perfused mouse, rat, guinea pig, and also bovine hearts show considerable xanthine oxidoreductase activity, contrasting rabbit, porcine, and diseased human hearts.
Collapse
Affiliation(s)
- J W de Jong
- Thoraxcenter, Erasmus University Rotterdam, Netherlands
| | | | | | | | | | | |
Collapse
|
19
|
|
20
|
LoBalsamo L, Bergsland J, Lajos P, Feldman MJ. Prevention of reperfusion injury in ischemic-reperfused hearts by oxypurinol and allopurinol. Transpl Int 1989; 2:218-22. [PMID: 2627264 DOI: 10.1007/bf02414538] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
We investigated the effects of the xanthine oxidase inhibitor allopurinol and its metabolite oxypurinol on isolated rabbit hearts. To assess the potential role of these drugs in preventing reperfusion injury, hearts were perfused using Langendorff techniques, held globally ischemic for 3 h at 15 degrees C, and then reperfused. During perfusion, hearts received Krebs-Henseleit solution maintained at 37 degrees C. Aortic perfusion pressure was held constant at 80 cm H2O. Prior to ischemia, hearts were arrested with a constant volume of KCl cardioplegia. Using a left ventricular (LV) balloon, developed pressures were measured prior to and following global ischemia. In addition, coronary circulation (CC) was measured before and after ischemia. All hearts were paced at 260 beats/min. We studied four groups: group 1 received 1 mM allopurinol, group 2 received 1 mM oxypurinol, group 3 received 90 IU/ml superoxide dismutase (SOD) plus 8085 IU/ml catalase (CAT), and group 4 received no treatment and served as a control. Each group consisted of 8 animals. Hearts receiving drug treatment did so during the first 5 min of reperfusion. Displaying all data as a function of LV volume, postischemic values were compared to preischemic values. Multivariate analysis and Tukey tests were used to detect significant differences between groups. When compared to the control group, all drug-treated groups significantly recovered end-diastolic function. Peak systolic pressure decreased significantly in the SOD/CAT group as compared to all other groups.(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
Affiliation(s)
- L LoBalsamo
- Department of Surgery, Buffalo Veterans Administration Medical Center, NY
| | | | | | | |
Collapse
|
21
|
Smoleński RT, Składanowski AC, Perko M, Zydowo MM. Adenylate degradation products release from the human myocardium during open heart surgery. Clin Chim Acta 1989; 182:63-73. [PMID: 2752581 DOI: 10.1016/0009-8981(89)90150-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Purine degradation products were determined in the human heart coronary sinus effluent collected from patients undergoing cardiac surgery, during infusion of a cardioplegic solution. At the onset of cardiopulmonary bypass the mean concentrations of adenosine, inosine and hypoxanthine were 0.1, 0.5 and 0.3 mumol/l, respectively. Ischemic arrest leads to a progressive increase of the respective levels to 1.4 17.8 and 9.6 mumol/l after 60-80 min of ischemia. Xanthine concentration was undetectable (less than 0.2 mumol/l) throughout. A substantial urate release (20 mumol/l) was observed which decreased with the duration of ischemia. Xanthine oxidoreductase activity in human myocardium was found to be below the detection limit (0.1 mU/g wet weight). Thus, urate release represented wash out of urate which had accumulated in the tissue.
Collapse
Affiliation(s)
- R T Smoleński
- Department of Biochemistry, Academic Medical School, Debinki, Poland
| | | | | | | |
Collapse
|
22
|
LoBalsamo L, Bergsland J, Lajos P, Feldman MJ. Prevention of reperfusion injury in ischemic-reperfused hearts by oxypurinol and allopurinol. Transpl Int 1989. [DOI: 10.1111/j.1432-2277.1989.tb01870.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
23
|
Crome R, Manning AS. Allopurinol and reperfusion-induced arrhythmias: increased protection by simultaneous administration of anti-oxidant enzymes. Cardiovasc Drugs Ther 1988; 2:295-304. [PMID: 3154913 DOI: 10.1007/bf00054636] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
We have assessed whether the xanthine oxidase inhibitor, allopurinol, can afford maximal protection against the formation of reperfusion-induced arrhythmias or whether the addition of free radical scavengers and anti-oxidants can increase this protection. Using an anesthetized rat preparation with transient coronary artery occlusion, we have compared the ability of allopurinol pretreatment alone to that of a combination therapy of allopurinol, superoxide dismutase, and catalase to reduce the incidence of reperfusion-induced arrhythmias. While both regimes reduced the incidence of reperfusion-induced ventricular fibrillation (from 87% to 40%, p less than 0.05 by allopurinol alone; and to 13%, p less than 0.01 by combination therapy), and both treatments eliminated mortality, only combination therapy reduced the incidence of reperfusion-induced ventricular tachycardia (from 87% to 40%, p less than 0.05). Furthermore, using an arrhythmia score analysis, combination therapy was shown to offer significantly greater protection than allopurinol alone. This additional protection afforded by combination therapy was also demonstrated by significant decreases in log10 duration of fibrillation and log10 number of premature ventricular complexes compared with allopurinol alone. Both allopurinol and combination therapy also significantly delayed the ischemia-induced increases in ST segment elevation, although there was no difference between the two drug-treated groups. We conclude from these results that allopurinol does not offer maximal protection against reperfusion-induced arrhythmias and that the addition of more general anti-oxidant therapy can increase this protection.
Collapse
Affiliation(s)
- R Crome
- Department of Biology, Roche Products Limited, Welwyn Garden City, Hertfordshire, England
| | | |
Collapse
|
24
|
Bailey IA, Blackwell CP, Woodward B. Chemiluminescence measurements of xanthine oxidase and xanthine dehydrogenase activity in four types of cardiovascular cell. Basic Res Cardiol 1988; 83:392-400. [PMID: 3190657 DOI: 10.1007/bf02005825] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The activity and location of xanthine oxidase (EC.1.2.3.2.) and xanthine dehydrogenase (EC.1.2.1.37) have been measured using luminol-enhanced chemiluminescence in four types of cell from the cardiovascular system (neonatal and adult rat cardiac myocytes, rat aortic vascular smooth muscle cells, rat cardiac fibroblasts and human umbilical vein endothelial cells). The detection system developed was both rapid and reproducible and could be used on sub-milligram quantities of cells. Xanthine oxidase was located primarily in cells derived from the vasculature and especially in endothelial cells, as was xanthine dehydrogenase. Only neonatal myocytes had more dehydrogenase activity than oxidase. The significance of the location and activity of these enzymes is discussed in relation to the pathology of myocardial ischaemia, arrhythmogenesis and microvascular disorders.
Collapse
Affiliation(s)
- I A Bailey
- ICI Pharmaceuticals Division, Macclesfield, Cheshire, U.K
| | | | | |
Collapse
|
25
|
Brown JM, Terada LS, Grosso MA, Whitmann GJ, Velasco SE, Patt A, Harken AH, Repine JE. Xanthine oxidase produces hydrogen peroxide which contributes to reperfusion injury of ischemic, isolated, perfused rat hearts. J Clin Invest 1988; 81:1297-301. [PMID: 3127425 PMCID: PMC329662 DOI: 10.1172/jci113448] [Citation(s) in RCA: 107] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Three lines of investigation indicated that hydrogen peroxide (H2O2) from xanthine oxidase (XO) contributes to cardiac dysfunction during reperfusion after ischemia. First, addition of dimethylthiourea (DMTU), a highly permeant O2 metabolite scavenger (but not urea) simultaneously with reperfusion improved recovery of ventricular function as assessed by ventricular developed pressure (DP), contractility (+dP/dt), and relaxation rate (-dP/dt) in isolated Krebs-Henseleit-perfused rat hearts subjected to global normothermic ischemia. Second, hearts from rats fed tungsten or treated with allopurinol had negligible XO activities (less than 0.5 mU/g wet myocardium compared with greater than 6.0 mU/g in control hearts) and increased ventricular function after ischemia and reperfusion. Third, myocardial H2O2-dependent inactivation of catalase occurred after reperfusion following ischemia, but not after ischemia without reperfusion or perfusion without ischemia. In contrast, myocardial catalase did not decrease during reperfusion of ischemic hearts treated with DMTU, tungsten, or allopurinol.
Collapse
Affiliation(s)
- J M Brown
- Department of Surgery, University of Colorado, Health Sciences Center, Denver 80262
| | | | | | | | | | | | | | | |
Collapse
|
26
|
|
27
|
Bindoli A, Cavallini L, Rigobello MP, Coassin M, Di Lisa F. Modification of the xanthine-converting enzyme of perfused rat heart during ischemia and oxidative stress. Free Radic Biol Med 1988; 4:163-7. [PMID: 3162724 DOI: 10.1016/0891-5849(88)90024-x] [Citation(s) in RCA: 58] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The reversible and irreversible conversion of xanthine dehydrogenase to xanthine oxidase during ischemia/reperfusion and oxidative stress induced by hydrogen peroxide or diamide and its relationship with glutathione and protein SH groups were studied. The direct spectrophotometric measurement of the various forms of the xanthine-converting enzyme indicates that, in the fresh rat heart or after normoxic perfusion, there always is a basal level of 80% xanthine dehydrogenase and 20% of xanthine oxidase (15% irreversible and 5% reversible) that could contribute to the background production of free radicals. There is no significant increase of irreversible xanthine oxidase during ischemia nor during reperfusion. After global ischemia the reversible oxidase shows almost no increase while, when ischemia is followed by reperfusion, there is a limited increase (less then 9%) of the reversible xanthine oxidase. In the latter conditions there is a decrease of glutathione and of SH groups of about 70% and 25%, respectively. Perfusion for 1 h with oxidizing agents like hydrogen peroxide (60 microM) or diamide (100 microM) determines a marked conversion of xanthine dehydrogenase to reversible xanthine oxidase of about 40% and 60%, respectively; this oxidase activity partially reconverts to the dehydrogenase after withdrawing the oxidizing agents from the perfusion medium. The level of irreversible xanthine oxidase remains unchanged in all the conditions tested. Both hydrogen peroxide and diamide induce a strong decrease in SH groups and depletion of glutathione. The xanthine dehydrogenase----xanthine oxidase conversion thus appears to be sensitive to the redox state of thiol groups.
Collapse
Affiliation(s)
- A Bindoli
- Centro Studio Fisiologia Mitochondriale, C. N. R., Padova, Italy
| | | | | | | | | |
Collapse
|
28
|
Suleiman SA, Stevens JB. Purification of xanthine dehydrogenase from rat liver: a rapid procedure with high enzyme yields. Arch Biochem Biophys 1987; 258:219-25. [PMID: 3478001 DOI: 10.1016/0003-9861(87)90338-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Xanthine dehydrogenase (EC 1.2.1.37) was purified approximately 1000-fold from liver homogenates of adult male Sprague-Dawley rats. Enzyme recovery was good (greater than 20% of the starting activity was obtained), and the homogeneously pure enzyme had a molecular mass of approximately 300,000 Da. The purified protein exhibited a specific activity of 2470 units/mg protein and spectral properties identical to those of the best preparations of this enzyme reported by other investigators. Routine preparations of this enzyme also possess higher dehydrogenase:oxidase ratios (typically between 5 and 6) than do other xanthine dehydrogenase preparations so far reported in the literature. Maximum dehydrogenase:oxidase ratios, greater than 10, could be obtained from this procedure if only peak dehydrogenase fractions from the chromatography columns were saved. The present small-scale purification method, which can be completed in 48-60 h, utilizes ammonium sulfate fractionation, Sephadex G-200 column chromatography, Blue Dextran-Sepharose column chromatography, and preparative gel electrophoresis.
Collapse
Affiliation(s)
- S A Suleiman
- Division of Environmental Health, School of Public Health, University of Minnesota, Minneapolis 55455
| | | |
Collapse
|
29
|
Abstract
Myocardial xanthine oxidase has been associated with reoxygenation injury induced by oxygen radicals. The damage due to myocardial ischemia and reperfusion increases with age; therefore, one would expect to find more xanthine oxidase in adult than in young hearts. Consequently, we studied the age-dependence of xanthine oxidoreductase activity in hearts, in addition to the localization of the enzyme in cultured rat-heart cells. We measured xanthine oxidase plus dehydrogenase activity in homogenates of hearts and in homogenates of cultured neonatal myocytes and nonmuscular cells. In rat heart homogenates, xanthine oxidoreductase increased from 0.5 +/- 0.1 mU/g wet wt (newborn, mean +/- SD) to 25 +/- 4 mU/g (age 15 weeks, p less than 0.001). The value for adult rabbit heart was more than 1,000 times lower and hardly detectable. Therefore, we did not study young rabbit hearts. In rat myocyte cultures, xanthine oxidoreductase activity increased from 4.2 +/- 1.6 mU/g protein (2nd day of culture) to 17 +/- 4 mU/g (4th day, p less than 0.005). The activity in nonmuscular cells increased much more, from 10.1 +/- 1.1 to 117 +/- 25 mU/g (p less than 0.002). The age-related increase of xanthine oxidoreductase activity in rat heart is in agreement with the implied role in reperfusion damage by the enzyme. Whether myocytes, in which the enzyme has a low activity, could be damaged in this way, remains to be studied.
Collapse
Affiliation(s)
- B Schoutsen
- Cardiochemical Laboratory, Thoraxcenter, Erasmus University Rotterdam, The Netherlands
| | | |
Collapse
|
30
|
Muxfeldt M, Schaper W. The activity of xanthine oxidase in heart of pigs, guinea pigs, rabbits, rats, and humans. Basic Res Cardiol 1987; 82:486-92. [PMID: 3426527 DOI: 10.1007/bf01907096] [Citation(s) in RCA: 110] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
We isolated and purified xanthine oxidase by Sephadex gel filtration and assayed the activity of the enzyme by urate production which we measured by HPLC and UV absorption at 290 nm. We applied this method to extracts of liver and heart of rats, guinea pigs, rabbits, and pigs and to heart of dogs and humans. We found that pig hearts do not exhibit xanthine oxidase activity and that human and rabbit hearts produced small amounts of urate only after hours of incubation. We conclude that xanthine oxidase does probably not play an important part in the mechanisms leading to myocardial infarction using the free radical generating pathway, because it is absent in one species (pig) and barely detectable in two others (rabbit and man) that are known for their rapid and complete infarction following acute coronary occlusion.
Collapse
Affiliation(s)
- M Muxfeldt
- Max Planck Institute, Department of Experimental Cardiology, Bad Nauheim, FRG
| | | |
Collapse
|
31
|
|
32
|
Moorhouse PC, Grootveld M, Halliwell B, Quinlan JG, Gutteridge JM. Allopurinol and oxypurinol are hydroxyl radical scavengers. FEBS Lett 1987; 213:23-8. [PMID: 3030809 DOI: 10.1016/0014-5793(87)81458-8] [Citation(s) in RCA: 302] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Allopurinol is a scavenger of the highly reactive hydroxyl radical (k2 approx. 10(9) M-1 X s-1). One product of attack of hydroxyl radical upon allopurinol is oxypurinol, which is a major metabolite of allopurinol. Oxypurinol is a better hydroxyl radical scavenger than is allopurinol (k2 approx. 4 X 10(9) M-1 X s-1) and it also reacts with the myeloperoxidase-derived oxidant hypochlorous acid. Hence the protective actions of allopurinol against reperfusion damage after hypoxia need not be entirely due to xanthine oxidase inhibition.
Collapse
|
33
|
Abstract
Little is known about postnatal changes in myocardial purine metabolism. We therefore studied how ATP catabolism was affected by hypothermia and ischaemia in neonatal and adult hearts. Hypothermia during ischaemia protected isolated adult and newborn hearts against ATP decline. Reperfusion after normothermic ischaemia resulted in higher ATP levels in newborn hearts with less release of ATP-catabolites. During normoxia adult hearts released mainly urate (80% of total purine release), while newborns released mainly hypoxanthine (64%). During early reperfusion adult and newborn hearts released mainly inosine (50-60%). The very low xanthine oxidase activity in the neonatal heart could be an important factor in the observed ATP preservation during reperfusion.
Collapse
Affiliation(s)
- J W de Jong
- Cardiochemical Laboratory, Erasmus University Rotterdam, The Netherlands
| | | |
Collapse
|
34
|
Grum CM, Ragsdale RA, Ketai LH, Shlafer M. Absence of xanthine oxidase or xanthine dehydrogenase in the rabbit myocardium. Biochem Biophys Res Commun 1986; 141:1104-8. [PMID: 3468948 DOI: 10.1016/s0006-291x(86)80157-7] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
We directly measured the activity of the enzymes xanthine oxidase and xanthine dehydrogenase in rabbit and rat hearts, using a sensitive radiochemical assay. Neither xanthine oxidase activity nor xanthine dehydrogenase activity was detected in the rabbit heart. In the rat heart, xanthine oxidase activity was 9.1 +/- 0.5 mIU per gram wet weight and xanthine dehydrogenase activity was 53.0 +/- 1.9 mIU per gram wet weight. These results argue against the involvement of the xanthine oxidase/xanthine dehydrogenase system as a mechanism of tissue injury in the rabbit heart, and suggest that the ability of allopurinol to protect the rabbit heart against hypoxic or ischemic damage must be due to a mechanism other than inhibition of these enzymes.
Collapse
|
35
|
Abstract
The enzyme xanthine: acceptor oxidoreductase found in rat heart equilibrates between three forms differing in electron acceptor specificity. Form D transfers electrons exclusively to NAD+ and accounts for 85% of total oxidoreductase activity. Form O transfers electrons to molecular oxygen and accounts for 8%. The D/O form prefers NAD+, but without NAD+ transfers electrons to oxygen. Interconversion from D to O and O to D forms is catalyzed by sulfhydryl group-modifying reagents: Cd2+, Cu2+, disulfiram, and heating with dithiothreitol. This suggests that sulfhydryl groups participate in the first stage of enzyme conversion. The NADH/NAD+ concentration ratio may regulate the dehydrogenase activity of xanthine:acceptor oxidoreductase (NAD+-dependent activity of D and D/O forms). Accumulating NADH inhibits hypoxanthine hydroxylation. The amount of form O increases during cardiac ischemia, facilitating superoxide radical-ion generation. Also, NADH/NAD+ does not regulate form O, promoting adenylate nucleotide pool depletion, especially in the heart which has low de novo purine nucleotide synthesis.
Collapse
|
36
|
Ambrosio G, Becker LC, Hutchins GM, Weisman HF, Weisfeldt ML. Reduction in experimental infarct size by recombinant human superoxide dismutase: insights into the pathophysiology of reperfusion injury. Circulation 1986; 74:1424-33. [PMID: 3779923 DOI: 10.1161/01.cir.74.6.1424] [Citation(s) in RCA: 341] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
To determine the importance of reperfusion injury and the ability of the free-radical scavenger recombinant human superoxide dismutase (h-SOD) to prevent it, open-chest dogs underwent 90 min of proximal circumflex coronary artery occlusion, and only at the moment of reperfusion received either h-SOD (400,000 IU bolus into the left atrium followed by a 300,000 IU iv infusion over 1 hr) or saline. After 48 hr the surviving animals were killed and measurements were made of the risk region (by postmortem angiography) and infarct size (by gross pathology). All measurements were made by investigators blinded to treatment given, and the code was broken only at the end of the study. Hemodynamic variables and collateral flow during ischemia were similar in the two groups. Infarct size in control animals (n = 8) averaged 22.4 +/- 3.1% of the left ventricle and 52.2 +/- 7.1% of the risk region, compared with 13.3 +/- 0.8% of the left ventricle and 33.6 +/- 2.1% of the risk region in h-SOD-treated dogs (n = 8) (p less than .05). Infarcts in treated animals were not only smaller, but also exhibited a distinctive "patchiness," suggesting protection along vascular distributions. Furthermore, analysis of the relationship between infarct size and collateral flow measured during ischemia in the two groups indicated that protection by h-SOD was greatest in animals with the lowest collateral flows. This study supports the concept that reperfusion of ischemic myocardium results in a separate component of cell damage, presumably linked to the generation of oxygen free radicals on reflow. Since the h-SOD preventable reperfusion component of injury was most pronounced in hearts with the most severe ischemia, scavenging of oxygen radicals at the time of reflow may offer a novel and particularly promising therapeutic approach for the protection of ischemic myocardium.
Collapse
|
37
|
Achterberg PW, Stroeve RJ, De Jong JW. Myocardial adenosine cycling rates during normoxia and under conditions of stimulated purine release. Biochem J 1986; 235:13-7. [PMID: 3741375 PMCID: PMC1146641 DOI: 10.1042/bj2350013] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Formation and rephosphorylation of adenosine (adenosine cycling) was studied in isolated rat hearts during normoxia and under conditions of stimulated purine formation. Hearts were infused with an inhibitor of adenosine kinase (5-iodotubercidin, 2 microM). In addition, perfusions were carried out with or without acetate, which is converted into acetyl-CoA, with simultaneous breakdown of ATP to AMP and purines. We found a linear, concentration-dependent, increase in normoxic purine release by acetate (5-20 mM). Differences in total purine release with or without iodotubercidin were taken as a measure of adenosine cycling. In normoxic hearts, iodotubercidin caused a minor increase in purine release (2.7 nmol/min per g wet wt.). Acetate (12.5 mM) increased purine release by 4.9 nmol/min per g, and its combination with inhibitor gave a large increase, by 14.2 nmol/min per g. This indicates a strongly increased adenosine cycling rate during acetate infusion. However, no significant differences in purine release were observed when iodotubercidin was infused during hypoxia, anoxia or ischaemia. The hypothesis that adenosine cycling is near-maximal during normoxia was not confirmed. Increased myocardial adenosine formation appears to be regulated by the availability of AMP and not by inhibition of adenosine kinase. This enzyme mainly functions to salvage adenosine in order to prevent excessive loss of adenine nucleotides.
Collapse
|
38
|
Mura U, Osman AM, Mohamed AS, Ipata PL. Studies on purine turnover in the camel (Camelus dromedarius) and zebu (Bos indicus). COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. B, COMPARATIVE BIOCHEMISTRY 1986; 84:589-93. [PMID: 3019607 DOI: 10.1016/0305-0491(86)90127-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Significantly higher hypoxanthine over uric acid ratios were found in camel plasma and urine, with respect to those of zebu. Enzyme levels of purine catabolism were markedly lower in camel than in zebu liver. Oxidation of hypoxanthine appears to be the limiting step of purine metabolism in camel liver. Any hepatic hypoxanthine appears to be actively converted into IMP in camel liver, rather than oxidized to uric acid.
Collapse
|
39
|
Abstract
We studied the effect of the calcium entry blocker nisoldipine on ATP catabolism in the rat heart, perfused according to Langendorff. Even 1 nM nisoldipine induced vasodilatation; concentrations of 30 nM and higher caused significant negative inotropy. The drug had a very strong affinity for silicon rubber tubing. Myocardial ischaemia was induced by lowering the perfusion pressure, which reduced flow without nisoldipine by 85%. The efflux of purine nucleosides and oxypurines rose 14 fold. Nisoldipine reduced this efflux of ATP catabolites dose-dependently. The highest concentration, 300 nM, suppressed ischaemic purine production completely. The action of the drug was antagonized by an increase in Ca2+-concentration in the perfusion fluid. We also showed the protective effect of nisoldipine on adenine nucleotides in freeze-clamped hearts. A concentration of 20 nM partially prevented the reduction of ATP and adenylate energy charge due to ischaemia. We conclude that relatively low doses of nisoldipine effectively prevent ATP breakdown in ischaemic rat heart.
Collapse
|
40
|
Schoutsen B, De Jong JW. Xanthine oxidase in rabbit plasma after application of a bovine milk preparation to small intestine. ARCHIVES INTERNATIONALES DE PHYSIOLOGIE ET DE BIOCHIMIE 1984; 92:379-84. [PMID: 6085554 DOI: 10.3109/13813458409080614] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The absorption of xanthine oxidase into the bloodstream was studied in rabbits given a milk/cream preparation, fortified with 130 U bovine milk xanthine oxidase or the milk/cream preparation alone (control). The preparations were injected trans-abdominally into the intestines. The rise of plasma xanthine oxidase/dehydrogenase activity was studied with a radioenzymatic assay with and without NAD+. In rabbits, which received the fortified mixture, the plasma xanthine oxidase increase in 8 h was six times more than the increase in control animals (P less than 0.001). In both groups plasma xanthine dehydrogenase activity increased 3-4 times (P less than 0.001), without a significant difference between the two groups. We estimate that only 0.003%, or about 3 micrograms, of the xanthine oxidase added, is absorbed as an active enzyme from the intestine.
Collapse
|