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Ren H, Zhou P, Shen X. Abnormal Phenylalanine Metabolism of Procapra przewalskii in Chronic Selenosis in Selenium-Enriched Habitats. Metabolites 2023; 13:982. [PMID: 37755262 PMCID: PMC10537570 DOI: 10.3390/metabo13090982] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 08/22/2023] [Accepted: 08/28/2023] [Indexed: 09/28/2023] Open
Abstract
Selenium (Se)-enriched habitats have led to chronic selenosis, seriously affecting the health and survival of Procapra przewalskii (P. przewalskii). Our targets were to explore the molecular mechanisms of chronic selenosis and to look for a new way to protect endangered species. The mineral contents of soils, grass, blood, and muscle were analyzed. The biochemical indices, antioxidant capability, and immune function were also investigated. The analyses of proteomics and metabolomics were also carried out. The results showed that the Se contents in the muscle and blood of P. przewalskii, and the soil and grass in the Se-enriched habitats were significantly higher than those in healthy pastures. The P. przewalskii in the Se-enriched habitats showed symptoms of anemia, decreased antioxidant capability, and low immune function. A total of 44 differential proteins and 36 differential metabolites were screened by analyzing their proteomics and metabolomics. These differential proteins and metabolites were involved in glycolysis pathway, amino acid biosynthesis, carbon metabolism, phenylalanine metabolism, and energy metabolism. In particular, phenylalanine metabolism was the common pathway of proteomics and metabolomics, which was an important finding in studying the mechanism of chronic selenosis in animals. This study will help us to further understand the mechanism of chronic selenosis in P. przewalskii, and it provides a scientific basis for the protection of endangered species in Se-enriched habitats.
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Affiliation(s)
- Hong Ren
- North Sichuan Medical College, Nanchong 637100, China;
| | - Ping Zhou
- State Key Laboratory of Sheep Genetic Improvement and Healthy Production, Xinjiang Academy of Agricultural and Reclamation Sciences, Shihezi 832000, China;
| | - Xiaoyun Shen
- State Key Laboratory of Sheep Genetic Improvement and Healthy Production, Xinjiang Academy of Agricultural and Reclamation Sciences, Shihezi 832000, China;
- School of Life Science and Engineering, Southwest University of Science and Technology, Mianyang 621010, China
- World Bank Poverty Alleviation Project Office in Guizhou, Guiyang 550004, China
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Hu C, Zhuang X, Zhang J, Wang T, Du S, Wang J, Peng X, Cao Q, Zhang M, Jiang Y. Serum Metabolomics in Patients with Coexisting NAFLD and T2DM Using Liquid Chromatography-Mass Spectrometry. Lab Med 2022; 53:360-368. [PMID: 35075477 DOI: 10.1093/labmed/lmab118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
OBJECTIVE Nonalcoholic fatty liver disease (NAFLD) and type 2 diabetes mellitus (T2DM) frequently coexist and can act synergistically to drive adverse outcomes of one another. This study aimed to unravel the metabolomic changes in patients with NAFLD and T2DM, to identify potential noninvasive biomarkers, and to provide insights for understanding the link between NAFLD and T2DM. METHODS Three hundred participants aged 35 to 70 years who were diagnosed with NAFLD (n = 100), T2DM (n = 100), or a comorbidity of NAFLD and T2DM (n = 100) were included in this study. Anthropometrics and routine blood chemistry were assessed after overnight fast. The global serum metabolomic analysis was performed by ultra-performance liquid chromatography-Orbitrap mass spectrometry. Multivariate data analysis methods were utilized to identify the potential biomarkers. RESULTS A set of serum biomarkers that could effectively separate NAFLD from NAFLD + T2DM and T2DM from NAFLD + T2DM were identified. We found that patients with coexisting NAFLD and T2DM had significantly higher levels of total protein (TP), triglycerides (TG), glucose in urine, and gamma-hydroxybutyric acid than those with NAFLD and had significant increased levels of TP, albumin, alanine aminotransferase, aspartate aminotransferase, total cholesterol, cholinesterase, TG, low-density lipoprotein, and apolipoprotein A when compared to patients with T2DM. CONCLUSION The metabolomics results provide evidence that the comorbidity of NAFLD and T2DM considerably altered patients' metabolomics patterns compared to those of patients with only NAFLD or T2DM.
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Affiliation(s)
- Cheng Hu
- Experiment Center for Science and Technology, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Xiaoyu Zhuang
- Experiment Center for Science and Technology, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Jiaqi Zhang
- Experiment Center for Science and Technology, Shanghai University of Traditional Chinese Medicine, Shanghai, China
- Shanghai TCM-Integrated Institute of Vascular Anomalies, Shanghai TCM-Integrated Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Tao Wang
- Department of Gastroenterology, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Shengnan Du
- Department of Gastroenterology, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Jinping Wang
- Department of Gastroenterology, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Xuelian Peng
- Department of Gastroenterology, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Qin Cao
- Department of Gastroenterology, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Mingcai Zhang
- Shuguang Hospital affiliated with Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Yuanye Jiang
- Experiment Center for Science and Technology, Shanghai University of Traditional Chinese Medicine, Shanghai, China
- Department of Gastroenterology, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
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Hu C, Wang T, Zhuang X, Sun Q, Wang X, Lin H, Feng M, Zhang J, Cao Q, Jiang Y. Metabolic analysis of early nonalcoholic fatty liver disease in humans using liquid chromatography-mass spectrometry. J Transl Med 2021; 19:152. [PMID: 33858428 PMCID: PMC8050915 DOI: 10.1186/s12967-021-02820-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Accepted: 04/09/2021] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Nonalcoholic fatty liver disease (NAFLD) is a common metabolic disease that affects 20-30% of individuals worldwide. Liver puncture remains the gold standard for the diagnosis of liver diseases despite limitations regarding invasive nature and sample variability. It is of great clinical significance to find noninvasive biomarkers to detect and predict NAFLD. OBJECTIVE The aims of this study were to identify potential serum markers in individuals with early-stage NAFLD and to advance the mechanistic understanding of this disease using a high-throughput mass spectrometry-based untargeted metabolomics approach. METHODS One hundred and twelve patients with early-stage NAFLD aged 18-55 were recruited according to the guidelines. The control group included 112 healthy participants. The demographic, anthropometric, clinical and laboratory data of all participants were systematically collected. Serum samples were obtained after an overnight fast. The comprehensive serum metabolomic analysis was performed by ultra-performance liquid chromatography-Orbitrap mass spectrometry. The resultant data was processed by Compound Discover and SIMCA-P software to validate the potential biomarkers. Significantly altered metabolites were evaluated by variable importance in projection value (VIP > 1) and ANOVA (p < 0.01). Pathway analysis was performed using MetaboAnalyst 4.0. RESULTS The liver function test of early NAFLD patients showed no statistical differences to control group (p > 0.05). However, obvious differences in blood lipids were observed between subjects with NAFLD and controls (p < 0.001). In total, 55 metabolites showed significant changes in experimental group were identified. The area under curve (AUC) values deduced by receiver operating curve (ROC) analysis indicated that these newly identified biomarkers have high predictability and reliability. Of these, 15 metabolites with AUC greater than 0.9 were of great diagnostic value in early NAFLD patients. CONCLUSION In this study, a total of 15 serum metabolites were found to strongly associate with early NAFLD. These biomarkers may have great clinical significance in the early diagnosis of NAFLD, as well as to follow response to therapeutic interventions.
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Affiliation(s)
- Cheng Hu
- Experiment Center for Science and Technology, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China
| | - Tao Wang
- Department of Gastroenterology, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, 164 Lanxi Road, Shanghai, 200062, China
| | - Xiaoyu Zhuang
- Experiment Center for Science and Technology, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China
| | - Qiaoli Sun
- Institute of Digestive Diseases, Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, 200032, China
| | - Xiaochun Wang
- Department of Gastroenterology, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, 164 Lanxi Road, Shanghai, 200062, China
| | - Hui Lin
- Department of Gastroenterology, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, 164 Lanxi Road, Shanghai, 200062, China
| | - Mingli Feng
- Department of Gastroenterology, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, 164 Lanxi Road, Shanghai, 200062, China
| | - Jiaqi Zhang
- Experiment Center for Science and Technology, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China.
- Shanghai TCM-Integrated Institute of Vascular Anomalies, Shanghai TCM-Integrated Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, 200082, China.
| | - Qin Cao
- Department of Gastroenterology, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, 164 Lanxi Road, Shanghai, 200062, China.
| | - Yuanye Jiang
- Department of Gastroenterology, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, 164 Lanxi Road, Shanghai, 200062, China.
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Serum phenylalanine concentration as a marker of liver function in obese patients before and after bariatric surgery. Obes Surg 2008; 19:883-9. [PMID: 18431611 DOI: 10.1007/s11695-008-9521-z] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2008] [Accepted: 03/27/2008] [Indexed: 02/07/2023]
Abstract
BACKGROUND Human obesity is associated with increased serum phenylalanine concentration, which is probably caused by liver dysfunction related to liver steatosis. This study examines whether improvements of liver function after bariatric surgery is associated with a decrease of serum phenylalanine concentration caused by an increase of phenylalanine metabolism. METHOD Serum phenylalanine and alanine aminotransferase (an independent predictor of liver steatosis) concentrations as well as several parameters related to obesity were measured in 16 obese patients (seven men and nine women) before and 6 months after vertical banded gastroplasty. Ten (six men and four women) lean, healthy subjects served as controls. RESULTS Obese patients before surgery had approximately twofold higher serum phenylalanine concentration than control subjects. The serum phenylalanine concentration decreased 6 months after bariatric surgery. Serum alanine aminotransferase (ALT) concentration was higher in obese patients before surgery, and decreased 6 months after bariatric surgery. Changes in serum phenylalanine concentration correlated positively with changes of ALT concentration (r = 0.75; p < 0.001). The body weight, BMI, HOMA-IR, serum triacylglycerol, LDL-cholesterol/HLD-cholesterol ratio, leptin, insulin, and glucose concentrations were higher in obese patients, and decreased 6 months after bariatric surgery. Serum HDL-cholesterol concentration was lower in obese patients before surgery than in control subjects and increased 6 months after surgery. CONCLUSION Results obtained indicate that bariatric surgery-induced weight loss had beneficial effects on several laboratory parameters including serum phenylalanine, ALT, lipid concentrations and insulin resistance. A strong positive correlation between serum phenylalanine and serum ALT concentrations suggests that deterioration of liver function in obese patients is contributing to a decrease in phenylalanine metabolism and consequently to the increase of serum phenylalanine concentration. One can suppose that serum phenylalanine concentration could be noninvasive marker of liver dysfunction associated with liver steatosis in obese patients.
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Gallardo-Wong I, Morán S, Rodríguez-Leal G, Castañeda-Romero B, Mera R, Poo J, Uribe M, Dehesa M. Prognostic value of 13C-phenylalanine breath test on predicting survival in patients with chronic liver failure. World J Gastroenterol 2007; 13:4579-85. [PMID: 17729409 PMCID: PMC4611830 DOI: 10.3748/wjg.v13.i34.4579] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To evaluate the prognostic value of percentage of 13C-phenylalanine oxidation (13C-PheOx) obtained by 13C-phenylalanine breath test (13C-PheBT) on the survival of patients with chronic liver failure.
METHODS: The hepatic function was determined by standard liver blood tests and the percentage of 13C-PheOx in 118 chronic liver failure patients. The follow-up period was of 64 mo. Survival analysis was performed by the Kaplan-Meier method and variables that were significant (P < 0.10) in univariate analysis and subsequently introduced in a multivariate analysis according to the hazard model proposed by Cox.
RESULTS: Forty-one patients died due to progressive liver failure during the follow-up period. The probability of survival at 12, 24, 36, 48 and 64 mo was 0.88, 0.78, 0.66, 0.57 and 0.19, respectively. Multivariate analysis demonstrated that Child-Pugh classes, age, creatinine and the percentage of 13C-PheOx (HR 0.338, 95% CI: 0.150-0.762, P = 0.009) were independent predictors of survival. When Child-Pugh classes were replaced by all the parameters of the score, only albumin, bilirubin, creatinine, age and the percentage of 13C-PheOx (HR 0.449, 95% CI: 0.206-0.979, P = 0.034) were found to be independent predictors of survival.
CONCLUSION: Percentage of 13C-PheOx obtained by 13C-PheBT is a strong predictor of survival in patients with chronic liver disease.
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Affiliation(s)
- I Gallardo-Wong
- Laboratory of Gastrohepatology Research, Hospital de Pediatria, CMN, Siglo XXI, IMSS. Av Cuauhtemoc 330, Colonia Doctores, Delegacion Cuauhtemoc, Mexico
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Kohno T, Ito A, Hosoi I, Hirayama J, Shibata K. Synthetic 13C-dipeptide breath test for the rapid assessment of pancreatic exocrine insufficiency in rats. Scand J Gastroenterol 2007; 42:992-9. [PMID: 17613930 DOI: 10.1080/00365520601155472] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
OBJECTIVE (13)C-breath tests have been investigated in order to assess pancreatic exocrine function using various (13)C-compounds, but they have not been accepted for routine clinical use. One of the barriers to their acceptance is that these tests are time-consuming and require up to several hours for breath collection. The purpose of this study was to design a novel (13)C-compound that would make a rapid (13)C-breath test for assessing exocrine pancreatic function possible. MATERIAL AND METHODS N-benzoyl-L-tyrosyl-1-(13)C-L-alanine was synthesized, and the characteristics of its cleavage in duodenal juice and in the duodenum of rats were examined. Thereafter, a (13)C-breath test was carried out in which N-benzoyl-L-tyrosyl-1-(13)C-L-alanine was given orally to pancreatic exocrine-insufficient and normal control rats. RESULTS N-benzoyl-L-tyrosyl-1-(13)C-L-alanine was readily cleaved and liberated 1-(13)C-L-alanine in the duodenal juice. Carboxypeptidase was a major contributor to the cleavage. When N-benzoyl-L-tyrosyl-1-(13)C-L-alanine was injected into the duodenum and orally administered to the rats, the (13)C atom% of CO(2) in breath increased rapidly. This indicated that N-benzoyl-L-tyrosyl-1-(13)C-L-alanine in the duodenum liberated (13)C-Ala on cleavage. (13)C-Ala is absorbed and metabolized to liberate (13)CO(2), which is exhaled. It was shown that the Delta(13)CO(2) ( per thousand) in the N-benzoyl-L-tyrosyl-1-(13)C-L-alanine breath test in the pancreatic exocrine-insufficient rats, in whom the absorption and metabolism of (13)C-Ala was unimpaired, was significantly lower than that in the control rats. CONCLUSIONS The rate of increase in the Delta(13)CO(2) ( per thousand) in the N-benzoyl-L-tyrosyl-1-(13)C-L-alanine breath test is expected to be proportional to the rate of N-benzoyl-L-tyrosyl-1-(13)C-L-alanine cleavage by pancreatic proteases in the duodenum. We propose the N-benzoyl-L-tyrosyl-1-(13)C-L-alanine breath test as a rapid test for assessing pancreatic exocrine function.
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Affiliation(s)
- Tadashi Kohno
- Fundamental Technology Department, Tokyo Gas Co. Ltd., Tokyo, Japan
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Neumann S, Welling H, Thuere S. Evaluation of Serum L-phenylalanine Concentration as Indicator of Liver Disease in Dogs: A Pilot Study. J Am Anim Hosp Assoc 2007; 43:193-200. [PMID: 17615399 DOI: 10.5326/0430193] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Because essential amino acids are metabolized in the liver, liver diseases may impair their catabolism. In this study, serum L-phenylalanine concentrations in 28 dogs with liver diseases were compared with those of 28 healthy dogs and 13 dogs with nonhepatic diseases. Dogs with liver diseases had significantly increased L-phenylalanine serum concentrations compared to healthy dogs (P<0.001) and to those with nonhepatic diseases (P<0.01). There were no significant differences among the L-phenylalanine serum concentrations of dogs with different degrees of liver diseases. The sensitivity and specificity of L-phenylalanine to fasting bile acids were comparable.
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Affiliation(s)
- Stephan Neumann
- Small Animal Clinic, Institute of Veterinary Medicine, University of Goettingen, Goettingen, Germany
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Yan WL, Sun DY, Lin XT, Jiang YB, Sun X. L-[1-13C] phenylalanine breath test results reflect the activity of phenylalanine hydroxylase in carbon tetrachloride acute injured rat liver. Life Sci 2006; 78:838-43. [PMID: 16139311 DOI: 10.1016/j.lfs.2005.05.073] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2005] [Accepted: 05/23/2005] [Indexed: 02/07/2023]
Abstract
L-[1-13C] phenylalanine breath tests (PheBTs) have been used to determine the hepatocyte functional capacity of patients. This study investigated the relationship between the PheBT parameter 13C excretion rate constant (PheBT-k) and activity of the phenylalanine metabolic rate-limiting enzyme phenylalanine hydroxylase (PAH) in rat liver. We noted that the time-course curves of 13C excretion presented as a single peak, which appeared 2 min after administration of L-[1-13C] phenylalanine (13C-Phe). 13C excretion during exhalation can be divided into a slow phase and a rapid phase. The PheBT-k in rats with carbon tetrachloride acute liver injury was.significantly lower than that of control rats. The rapid phase 13C disposition constants of the acute liver injured rats did not differ from that of the controls. The peak value of 13C abundance in the breath of the acute liver injured rats was markedly higher than that of the control group. Total liver PAH activity in the acute liver injured rats was significantly lower than that in the control group. PheBT-k was highly correlated with the total activity of liver PAH (r = 0.92, P < 0.001). The present findings indicate that PheBT results reflect PAH activity levels. The PheBT-k parameter is a sensitive index that can be used to evaluate PAH function in the liver. In addition we demonstrated that the rodent model used in this study is a valuable tool for basic research studies of the breath test.
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Affiliation(s)
- Wei-Li Yan
- Department of Gastroenterology, Huashan Hospital Affiliated to Fudan University, Shanghai 200040, P.R. China.
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Yan W, Xiong P, Liu Z, Huang G. Results of L-[1-13C]phenylalanine breath test with air isotope ratio mass spectrometry can reflect the activity of phenylalanine hydroxylase in cirrhotic rat liver. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2006; 20:602-8. [PMID: 16429477 DOI: 10.1002/rcm.2345] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
The L-[1-13C]phenylalanine breath test (PheBT) could potentially advance the evaluation of hepatocyte function and liver functional reserve. However, because the factors influencing PheBT results have not been clarified, the clinical application of the test has been limited. This study investigated the relationship between the parameters of PheBT, performed with air isotope ratio mass spectrometry, and the activity of phenylalanine hydroxylase (PAH), the phenylalanine metabolism rate-limiting enzyme, in rat liver, and proposes valid parameters for the assessment of liver function. Chronic injury to the liver was induced by the administration of CCl4 to male Sprague-Dawley rats for either 8 or 12 weeks. Livers from rats in the two cirrhotic groups were discolored, enlarged and roughly textured, with cells filled with fat granules of various sizes, pseudolobuli formations, and regenerated tubercles. Of the 12 parameters tested, only the unit liver weight (LW) breath test parameters, including the maximum abundance of 13C in breath (13Cmax/LW), 13C abundance in breaths 2 and 7 min after administration of L-[1-(13)C]phenylalanine (13C-phe) (13C2/LW and 13C7/LW), cumulative 13C excretion 10 and 30 min after 13C-phe administration (AUC10/LW and AUC30/LW), and the 13C excretion rate constant (PheBT-k/LW) were significantly affected in the chronic liver injury groups. There was no significant difference in the total PAH activity in liver among the three groups, but there was significant difference in unit LW PAH activity. Total PAH activity in the liver was significantly correlated with 13Cmax, 13C2, 13C7, AUC10, AUC30 and PheBT-k, while the unit LW PAH activity was significantly correlated with 13Cmax/LW, 13C2/LW, 13C7/LW, AUC10/LW, AUC30/LW and PheBT-k/LW. PheBT-k/LW was also correlated with biochemical indices that are used to assess liver function. The present findings indicate that the PheBT results based on air isotope ratio mass spectrometry can quantitatively reflect the change in total PAH activity in the livers of chronically injured rats. PheBT-k and PheBT-k/LW are the most sensitive among the test parameters, and can be used to assess liver functional reserve and hepatocyte damage at the molecular level.
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Affiliation(s)
- Weili Yan
- Department of Nuclear Medicine, Renji Hospital Affiliated to Shanghai Second Medical University, Shanghai 200127, China
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Yan W, Sun D, Lin X, Jiang Y, Sun X. [13C] phenylalanine breath test and hepatic phenylalanine metabolism enzymes in cirrhotic rats. Eur J Clin Invest 2005; 35:644-52. [PMID: 16178884 DOI: 10.1111/j.1365-2362.2005.01566.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
BACKGROUND Stable isotope 13C-labelled phenylalanine breath test has been applied to enable the quantitative evaluation of hepatic functional reserve, but the mechanism underlying the changes in function has not been resolved. This study evaluated the correlation between expression of the mRNA of key enzymes mediating phenylalanine metabolism and the metabolism of L-[1-13C] phenylalanine (13C-phe) assessed by the excretion of 13C-CO2 in the breath of rats with, and without, chronic hepatic injury induced by administration of carbon tetrachloride (CCl4). MATERIALS AND METHODS Male Sprague-Dawley (SD) rats (n = 29) were given subcutaneous injections of CCl4 to induce chronic hepatic injury. L-[1-13C] phenylalanine breath tests (PheBT) were then applied to the rats to assess hepatic function. Expression of phenylalanine hydroxylase (PHH) and tyrosine transaminase (TYT) mRNA in liver was detected by real-time fluorescence quantification RT-PCR, using TaqMan as the probe. It was then determined whether the PheBT results correlated with PHH and/or TYT mRNA expression. In addition, immunohistochemical labelling was used to visualize PHH protein expression in the control and injured liver tissue. RESULTS There were significant decreases in PheBT and PHH mRNA expression in the cirrhotic rats relative to the uninjured controls and these two measures of liver function were correlated. However, TYT mRNA expression was not changed by CCl4-induced liver injury. The immunohistochemical analysis revealed that PHH protein was expressed predominantly in the cytoplasm of liver cells. CONCLUSIONS The results of the PheBT were consistent with the changes in PHH gene expression following liver injury. The present findings indicate that decreased expression of the rate-limiting enzyme PHH, but not of TYT, might underlie the functional deficits detected as decreased PheBT. The 13C excretion rate constant per mass liver (PheBT-k/LW) was the most sensitive index that could be used to evaluate the PHH mRNA expression in the liver.
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Affiliation(s)
- W Yan
- Department of Gastroenterology, Huashan Hospital Affiliated to Fudan University, Shanghai, PR China.
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Koeda N, Iwai M, Kato A, Suzuki K. Validity of 13C-phenylalanine breath test to evaluate functional capacity of hepatocyte in patients with liver cirrhosis and acute hepatitis. Aliment Pharmacol Ther 2005; 21:851-9. [PMID: 15801920 DOI: 10.1111/j.1365-2036.2005.02409.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
BACKGROUND No definitive method for quantitative evaluation of hepatic function has as yet been established. AIM To investigate whether the (13)C-phenylalanine breath test would be useful for the evaluation of hepatic function in patients with liver cirrhosis and acute hepatitis. METHODS L-[1-(13)C]-phenylalanine was administered orally in a dose of 100 mg to 25 patients with liver cirrhosis, 22 patients with acute hepatitis and 10 healthy subjects. The relationships of the cumulative excretion with the (13)C-%dose/h, blood biochemical parameters and asialoscintigraphy were investigated. RESULTS In liver cirrhosis patients, the cumulative excretion showed correlations with hepatic function tests, asialoscintigraphy, clinical stage and portal hypertension. In acute hepatitis patients, the cumulative excretion showed correlations with hepatic function tests. There were positive correlations between the cumulative excretion and the (13)C-%dose/h at 20 min (Phe20) and (13)C-%dose/h at 30 min (Phe30) in liver cirrhosis and acute hepatitis patients. Multiple regression analysis demonstrated that total bilirubin, total cholesterol and absence of varices were independent determinants of cumulative excretion in liver cirrhosis patients and prothrombin time in acute hepatitis patients. CONCLUSION The (13)C-phenylalanine breath test may allow hepatic function to be evaluated non-invasively in liver cirrhosis and acute hepatitis patients, and the Phe20 and Phe30 may be useful for determination of function at a single time-point.
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Affiliation(s)
- N Koeda
- First Department of Internal Medicine, Iwate Medical University, School of Medicine, 19-1 Uchimaru, Morioka 020-8505, Iwate, Japan
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Yan WL, Jiang YB, Lin XT, Sun X, Rong L, Liang Q, Sun DY. Correlation between L-[1- 13C] phenlalanine breath test and activity of phenylalanine hydroxylase. Shijie Huaren Xiaohua Zazhi 2005; 13:516-520. [DOI: 10.11569/wcjd.v13.i4.516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To investigate the correlation between the result of L-[1-13C]phenylalanine breath test (PheBT) and the phenylalanine hydroxylase(PAH)activity of the liver in rats.
METHODS: PheBT was performed in Prague-Dawley (SD) rats with acute tetrachloride (CCl4) hepatitis (n = 10) and control SD rats (n = 10). 20mg/kg body weight L-[1-13C]phenylalanine (13C-phe) was administered via tail vein, and breath samples were taken before administration and at different time within 60 minutes after administration. 13CO2 abundance was measured with isotope ratio mass spectrometer, and 13C excretion rate constant (PheBT-k) was calculated. The PAH activity in the liver tissues was determined by enzyme-coupled assay.
RESULTS: After the intravenous administration of 13C-phe, 13C excretion reached the peak in two minutes in most acute hepatitis rats (8/10) and control rats (9/10). The time-course of 13C excretion had two phases: fast phase and slow phase. PheBT-k of CCl4 hepatitis rats was significantly less than that of normal control rats [(2.45±0.25)×10-2 /min vs (2.98±0.19)×10-2 /min, P<0.01]. There was no significant difference for 13C fast phase disposition constant between the two groups [(9.463.27)×10-2 /min vs (10.17±2.10)×10-2 /min, P>0.05]. However, the peak value of 13C excretion of acute hepatitis rats was significantly higher than that of controls [(204.33±35.80) vs (170.65±22.85) (P<0.05 )]. The PAH activity of whole liver of hepatitis rats was significantly lower than that of control rats (P<0.01). PheBT-k was highly correlated to the PAH activity of the whole liver (r = 0.92, P<0.01) in all rats.
CONCLUSION: It is strongly indicated that decreased activity of PAH of the whole liver is the most direct reason for decreased13C excretion rate in acute CCl4 hepatitis rats, and the PheBT-k can be used to quantify the degree of liver injure.
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