Objective: 

Alterations in surfactant production may play a role in the pathogenesis of lung dysfunction secondary to aging. Phosphatidylcholine (PC) and phosphatidylglycerol (PGL) are main surfactant components. The aim of the present study was to investigate the lung PC and PGL synthesis in old female rats with or without treatment with estrogens or phytoestrogens. We also investigated the possible involvement of nitric oxide and lipid peroxidation

Methods: 

Rats were randomly assigned to 2 groups A: intact and B: ovariectomized at 12 months. Rats were killed by decapitation at 14, 18, 22 months of age. Ovariectomized 24-months-old rats were divided into 3 groups: treated with estrogens (estradiol 125mg/week s.c.); treated with soy extract (phytosoya®, 312mg/kg/day in drinking water); non-treated animals. Two-months-old rats were used as young controls. Type II pneumocytes were isolated by enzymatic digestion, adherence separation of macrophages, and gradient purification. Cells were precultured for 24 h and then cultured for another 24 h. NO and CO release to the medium and LPO, cGMP and the incorporation of D-(U-14C) glucose into PC and PGL (cells) were determined.

Results: 

Age-reduced glucose incorporation into PC and PGL, while it increases LPO and cGMP content and NO and CO release. These effects were more apparent on ovariectomized rats. Both estrogens and phytoestrogens treatments were able to reduce age-induced effects.

Conclusions: 

Our results suggest that age may alter lung function by reducing its hydrophobic phospholipid content. Also they suggest that both Eo and Phyt could exert a protective effect on age-induced lung damage.