Fig. 4.

Collagen deposition in lung tissues. A: histological lung sections from pups exposed as described in methods were stained with Picro-Sirius red and assessed at day 28. B and C: positive-stained areas from lungs exposed to prenatal saline or LPS and postnatal room air (open bars) or 85% O₂ were quantified for number and total area. Five fields for each slide were averaged, and data were analyzed by 2-way ANOVA and modified t-test post hoc (n = 6 per group). Effects of prenatal LPS and postnatal hyperoxia exposure were observed in the numbers of Sirius red (SR) spots and total Sirius red area. Values are means ± SE. Identical symbols above bars indicate statistical significance between groups: *,**P ≤ 0.05; $,§,†,‡,††P ≤ 0.01.