Inhaled nitric oxide treatment inhibits neuronal injury after meconium aspiration in piglets.
BACKGROUND
Meconium aspiration-induced hypertensive lung injury is frequently associated with neuronal damage. Inhaled nitric oxide (iNO) is widely used in the treatment of pulmonary hypertension, but its effects on the brain are poorly known.


OBJECTIVE
The aim of this study was to determine the effects of iNO treatment on the neuronal tissue after meconium aspiration.


METHODS
71 anesthetized, catheterized and ventilated newborn piglets were studied for 6 h. Thirty-five piglets were instilled with a bolus of human meconium intratracheally and 36 piglets with saline instillation served as controls. Nineteen meconium piglets and 17 control piglets were continuously treated with 20 ppm of iNO, started at 30 min after the insult. The extent of neuronal injury was analysed histologically, and the levels of brain tissue lipid peroxidation products, reduced glutathione (GSH), myeloperoxidase activity and oxidized DNA were analysed as indicators of oxidative stress.


RESULTS
iNO treatment diminished the pulmonary hypertensive response caused by meconium aspiration, but did not change systemic or carotid hemodynamics. NO administration was associated with reduced neuronal injury and diminished amount of oxidized DNA in the hippocampus of the meconium piglets. Further, iNO treatment was associated with decreased level of GSH in the cortex, but no change in lipid peroxidation production or myeloperoxidase activity was detected in any of the studied brain areas.


CONCLUSIONS
Our results suggest that iNO treatment may inhibit DNA oxidation and neuronal injury in the hippocampus, associated with newborn meconium aspiration.
Aaltonen
Minna
M
Research Centre of Applied and Preventive Cardiovascular Medicine (CAPC), University of Turku, Kiinamyllynkatu 10, 20520 Turku, Finland. minkopo@utu.fi
Soukka
Hanna
H
Halkola
Lauri
L
Jalonen
Jarmo
J
Kalimo
Hannu
H
Holopainen
Irma E
IE
Kääpä
Pekka O
PO
D000080242:8-Hydroxy-2'-Deoxyguanosine; D000280:Administration, Inhalation; D000704:Analysis of Variance; D000818:Animals; D001238:Asphyxia Neonatorum / Q000188:drug therapy* / Q000209:etiology; D001794:Blood Pressure; D002302:Cardiac Output; D016022:Case-Control Studies; D002851:Chromatography, High Pressure Liquid; D003849:Deoxyguanosine / Q000031:analogs & derivatives / Q000378:metabolism; D005978:Glutathione / Q000378:metabolism; D006339:Heart Rate; D006801:Humans; D007231:Infant, Newborn; D007395:Interneurons / Q000473:pathology*; D015227:Lipid Peroxidation / Q000502:physiology; D008471:Meconium Aspiration Syndrome / Q000503:physiopathology*; D009569:Nitric Oxide / Q000008:administration & dosage / Q000627:therapeutic use*; D018384:Oxidative Stress / Q000502:physiology*; D009195:Peroxidase / Q000378:metabolism; D013056:Spectrophotometry, Ultraviolet; D034421:Sus scrofa; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism
D017392:Thiobarbituric Acid Reactive Substances; D009569:Nitric Oxide; D000080242:8-Hydroxy-2'-Deoxyguanosine; D009195:Peroxidase; D003849:Deoxyguanosine; D005978:Glutathione