부산대학교 도서관

Thirty-four in-vivo measurements of phosphorus-containing compounds were obtained by 31-P nuclear magnetic resonance (NMR) in low birthweight (LBW) appropriate-for-gestational-age infants (GA 24-35 wks, x BW 1150 g). Two infants, 590 g and 1120 g, intubated and ventilated, were studied without complication. Surface coil 31-P NMR spectra, ATP, phosphocreatine (Pcr), phosphodiester (PD), inorganic phosphate (Pi), phosphomonoester (PME), were obtained 1-9 times in each infant. Pcr/Pi, a measure of bioenergetic reserve and PME/β ATP, a precursor of membrane biosynthesis, in normal full term infants are: x Pcr/Pi=1.01 (range .64-1.38) and PME/ 8 ATP=1.67 (range 1.64-2.46). In LBW infants, x Pcr/Pi increased as a function of postnatal age (1-14 d: 0.82; > 14 d: 1.06) and of postconceptual age (< 32 wks: 0.82; 32-34 wks: 0.93; 35-37 wks: 0.95; > 38 wks: 1.14). Mean PME/β ATP decreased as a function of postconceptual age (< 32 wks: 2.02; 32-34 wks: 1.77; 35-37 wks: 1.76; ≥38 wks: 1.76), but not of postnatal age (0-14 d: 1.84; > 14 d: 1.80). Mean PD/β ATP increased as a function of postconceptual age (<32 wks: 1.75; 32-34 wks: 2.05; 35-37 wks: 2.23; ≥ 38 wks: 3.34). The ventilator-dependent infants fell well within their postnatal and postconceptual distribution. Regardless of postconceptual age, oxidative metabolism (Pcr/Pi) increased with duration of extrauterine life, possibly as a result of the difference between intrauterine and extrauterine PO2. However, brain growth potential (PME/β ATP, PD/β ATP) was more dependent on stage of postconceptual development.