Intra-tracheal (IT) administration of male or female MSC similarly improves alveolarization.

(a) Hematoxylin and eosin stained lung sections demonstrating improved alveolar structure in hyperoxia-exposed pups treated with IT male or female MSC. Original magnification X 200. Bars = 100 μm. IT male or female MSC similarly increased mean linear intercept (b) and decreased radial alveolar count (c). IT male or female MSC similarly improve RAC in female (d) and male (e) animals. (*P < 0.05; Room air (RA) vs hyperoxia- placebo (PL), † P <0.05; hyperoxia -PL vs hyperoxia male or female MSC). White bars are RA and black bars are hyperoxia.