Bone Abstracts

Glucocorticoids are the most commonly used drugs in medical therapy, released in stress and necessary for normal development in both humans and animals.

The aim of this study was to investigate the effect of prenatally administered dexamethasone (Dex), a synthetic glucocorticoid, on the histomorphometry of the femur in the offsprings of spiny mice, as a precocial species, characterized by high fertility, and the rapid development of the fetal, allowing the offsprings to the large autonomy shortly after birth.

The study was performed on four pregnant spiny mice. Time of the experiment included the prenatal period between the 20th day of gestation until birth (pregnancy lasts an average of 36–38 days). The mice from the experimental group received dexamethasone per os in a dose of 125 mg/kg BW daily. At the end newborns were weighted and euthanized. The femora were isolated, weighed and measured. Histology and histomorphometry of articular and growth plate were performed.

Maternal Dex treatment resulted in lower birth weight by 17%. Dex administration significantly reduced the thickness of the hypertrophy zone of growth plate by 34% and total thickness by 8.7%. In addition Dex decreased number of cells in the articular cartilage by 27% and decreased their diameter by 5%, significantly though. Dex also affected the structure and spatial distribution of thick and thin collagen fibers, lowering the proportion of thin fibers compared with control group. Moreover, Dex treatment considerably lowered amount of proteoglycans in articular and growth cartilages.

Glucocorticoids exposure to pregnant spiny mice affects cartilage development by accelerating maturity of collagen fibers and growth plate, along with presumably disrupts further longitudinal growth of long bones.

Declaration of interest: There is no conflict of interest.