title: Determination of total potentially available nucleosides in human milk from Asian women.
abstract: OBJECTIVE
  The objective was to measure the total potentially available nucleosides (TPAN) in breast milk from Asian women.
  
  
  METHODS
  One hundred sixty milk samples were collected from 135 healthy, lactating women in Hong Kong, the Philippines, and Singapore at four stages of lactation: colostrum (1 to 3 days postpartum), transitional (7 to 10 days postpartum), early mature (28 to 35 days postpartum), and late mature (90 to 100 days postpartum). Samples were pooled by site and stage of lactation before analysis.
  
  
  RESULTS
  The mean TPAN concentration was 203 microM/L (69.4 mg/L corrected for recovery). Average TPAN concentrations were 171.9 microM/L in colostrum, 208.1 microM/L in transitional milk, 221.6 microM/L in early mature milk, and 210.6 microM/L in late mature milk, with no notable differences between countries. The major sources of nucleosides were RNA (43.3% of TPAN) and free nucleotides (39.9% of TPAN). The average percentages of cytidine, uridine, guanosine, and adenosine monophosphates were 44.5%, 23.1%, 16.5%, and 16.1% of TPAN, respectively. The sources of nucleosides and percentages of nucleotide bases were similar for all stages of lactation. Over 91% of the TPAN was present in the non-cellular component except in colostrum.
  
  
  CONCLUSIONS
  The average TPAN level in Asian women is similar to that in European and American women, and free nucleotides in human milk represent less than half of the TPAN.
authors.affiliation: Abbott Laboratories, Abbott Park, Illinois 60064-6149, USA.
authors.forename: Randall L
authors.initials: RL
authors.lastname: Tressler
authors.forename: Mary B
authors.initials: MB
authors.lastname: Ramstack
authors.forename: Norman R
authors.initials: NR
authors.lastname: White
authors.forename: Bruce E
authors.initials: BE
authors.lastname: Molitor
authors.forename: Nancy R
authors.initials: NR
authors.lastname: Chen
authors.forename: Pedro
authors.initials: P
authors.lastname: Alarcon
authors.forename: Marc L
authors.initials: ML
authors.lastname: Masor
mesh_terms: D000328:Adult; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D003126:Colostrum / Q000737:chemistry*; D005260:Female; D006723:Hong Kong; D006801:Humans; D007774:Lactation; D008895:Milk, Human / Q000737:chemistry*; D009705:Nucleosides / Q000032:analysis*; D010679:Philippines; D012680:Sensitivity and Specificity; D012846:Singapore
chemical_list: D009705:Nucleosides