D. Boda et al., SURFACE-TENSION, GLUTATHIONE CONTENT AND REDOX RATIO OF THE TRACHEAL ASPIRATE FLUID OF PREMATURE-INFANTS WITH IRDS, Biology of the neonate, 74(4), 1998, pp. 281-288
Objective: Determination of the surface tension (ST), the total glutat
hione (GL) content and the ratio of oxidized glutathione (GSSG) to red
uced glutathione (GSH) in the tracheal aspirate (TA) of newborn infant
s with IRDS. Methods: The ST of the TA was determined by monitoring th
e fluid level pulsated in a capillary glass tube by means of a digital
ized videocomputerized picture analysis program, a technique developed
in our laboratory. The concentrations of GSSG and total GL in the TA
were determined enzymatically with glutathione reductase. All results
of laboratory tests were referred to the total phospholipid (PL) conce
ntration. Patients, Experimental Material: TA samples were collected f
rom 32 intubated premature and newborn infants admitted to the NICU wi
th IRDS during the first 2 weeks of their lives. Control samples were
obtained from 11 children prior to elective surgery. Results: The ST r
elative to the PL content (surface tension index, STI) was significant
ly lower in the newborns with IRDS than in the control group, and the
concentration of GSH in the TA was also markedly decreased in all IRDS
infants studied. The concentration of GSSG and the ratio of GSSG to G
SH were significantly higher in the severe cases and in those with an
unfavourable prognosis. Surfactant treatment had a protective effect a
gainst oxidative stress, it induced a decrease in both the GSSG concen
tration and in the GL redox ratio (GSSG/GSH) in the TA. There was a cl
ose correlation between the GSH content and the STI value of the sampl
es studied. Conclusion: Oxidation and consequent depletion of GSH in t
he TA may be an aggravating factor in the development of the insuffici
ent surface activity in intubated newborns with IRDS.