title: Evaluation of stable isotope labeling technique in measuring the tissues' protein fractional synthesis rates in rats.
abstract: OBJECTIVE
  The objective of this study was to evaluate the technique for measuring tissues' protein fractional synthesis rates with [L-(15)N]Leucine.
  
  
  METHODS
  Sixty male Sprague-Dawley rats were randomly assigned to different groups. After intravenous injection with [L-(15)N]Leucine, the enrichment of (15)N in different time intervals was measured with the same dosage and at the same time by variable dosage.
  
  
  RESULTS
  During the period from 0 to 30 minutes, there was nearly a linear increase in enrichment of (15)N in both the free amino acid pool and the bond amino acid pool in rats' tissues, and the peak was achieved at 30 minutes. With the increase of dosage, the fractional synthesis rates rose. However, when the dosage was more than 1.0 mmol/kg, there was no significant discrepancy.
  
  
  CONCLUSIONS
  For measuring the tissues' protein fractional synthesis rates with [L-(15)N]Leucine in rats, 30 minutes post-injection is optimal, and 1.0 mmol/kg is the most suitable dosage.
authors.affiliation: Department of Burns and Plastic Surgery, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China.
authors.forename: Jihong
authors.initials: J
authors.lastname: Zhou
authors.affiliation: Department of Surgery, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China.
authors.forename: Shengxian
authors.initials: S
authors.lastname: Fan
authors.affiliation: Institute of Soil Science, Chinese Academy of Sciences, Nanjing, China.
authors.forename: Yacheng
authors.initials: Y
authors.lastname: Cao
authors.affiliation: Institute of Soil Science, Chinese Academy of Sciences, Nanjing, China.
authors.forename: Mingfang
authors.initials: M
authors.lastname: Zhu
authors.affiliation: Institute of Soil Science, Chinese Academy of Sciences, Nanjing, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Han
authors.affiliation: Department of Burns and Plastic Surgery, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China.
authors.forename: Xueying
authors.initials: X
authors.lastname: Cao
authors.affiliation: Department of Surgery, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China liys@medmail.com.cn.
authors.forename: Yousheng
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Surgery, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China.
authors.forename: Jieshou
authors.initials: J
authors.lastname: Li
mesh_terms: D000596:Amino Acids / Q000097:blood / Q000378:metabolism; D000818:Animals; D007553:Isotope Labeling / Q000379:methods*; D008297:Male; D009587:Nitrogen Isotopes; D009928:Organ Specificity; D014176:Protein Biosynthesis; D017207:Rats, Sprague-Dawley; D013997:Time Factors
chemical_list: D000596:Amino Acids; D009587:Nitrogen Isotopes
keywords: [L-15N]Leucine; protein fractional synthesis rates; stable isotope