Effects of Inhaled Corticosteroids on the Growth Plates of Infant Rats

The most significant adverse effect of inhaled steroid administration in children is suppression of hypothalamic-pituitary-adrenal axis responsiveness and suppression of growth. This study evaluates the effects of inhaled corticosteroids on the growth plates in infant rats. Rats aged 10 days were divided into five groups. Low and high doses of budesonide and fluticasone propionate (50-200-250 mcg/day) were applied with a modified spacer for 10 days. The rat's tibias were then removed and the effects of the steroids on the growth plates were compared. Growth cartilage chondrocyte proliferation and apoptosis rates; IGF-1 and glucocorticoid receptor levels; and resting, proliferative, hypertrophic, and total zone (TZ) measurements were compared using immunohistochemical-staining methods. With high doses of fluticasone, growth plates were affected much more than with high doses of budesonide (p = 0.01). Fluticasone, particularly at a dose of 250 mcg, inhibited the growth plate with an intensive negative impact on all parameters.