Selenium deficiency augments the pulmonary toxic effects of oxygen exposure in the rat.
Selenium (Se) is a component of the antioxidant enzyme glutathione peroxidase (GSHPx). We wanted to determined whether Se deficiency predisposes to pulmonary O2 toxicity. Sixteen weanling rats were fed a Se-free diet (Se-). Sixteen rats fed the same diet had drinking water supplemented with 400 micrograms.l-1 sodium selenite (Se+). After 5 weeks, rats were killed after exposure to either 95% O2 or air for 36 h. Se concentration in blood, lung, liver, heart, muscle and spleen, and blood GSHPx activity were higher in Se+ than in Se- groups. Pulmonary oedema developed in both O2-exposed groups, but was more severe in Se-O2 group than in the Se+O2 group, as judged by the presence of pleural effusions (7 out of 8 versus 0 out of 8), elevated lavage protein concentration (173 +/- 17 versus 120 +/- 14 micrograms.ml-1), and higher wet/dry weight ratio (W:D) (5.8 +/- 0.07 versus 5.4 +/- 0.07). W:D correlated inversely with lung Se content in O2-exposed rats. Both O2-exposed groups had a reduction in the amount of less aggregated lavage phospholipid (PL) compared with the Se+air group. However, the Se-O2 group had increased total PL, because of an increase in more aggregated PL. We conclude that Se deficiency exacerbates pulmonary injury in O2-exposed rats, and that O2 toxicity is associated with an altered physical form of alveolar surfactant.
Hawker
F H
FH
Intensive Care Unit, Royal Prince Alfred Hospital, Camperdown, NSW, Australia.
Ward
H E
HE
Stewart
P M
PM
Wynne
L A
LA
Snitch
P J
PJ
D000818:Animals; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry; D005260:Female; D008168:Lung / Q000187:drug effects* / Q000378:metabolism; D010100:Oxygen / Q000633:toxicity*; D010743:Phospholipids / Q000378:metabolism; D011654:Pulmonary Edema / Q000209:etiology / Q000378:metabolism; D011663:Pulmonary Surfactants / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D012643:Selenium / Q000172:deficiency* / Q000378:metabolism; D013047:Specific Pathogen-Free Organisms
D010743:Phospholipids; D011663:Pulmonary Surfactants; D012643:Selenium; D010100:Oxygen