Background: All-trans-retinoic acid (ATRA), an active metabolite of vitamin A, plays a
significant role in controlling various physiological processes, including embryonic
development and epithelial differentiation. ATRA is utilized as a chemotherapeutic agent
for treating of acute promyelocytic leukemia (APL) in pediatric patients. Besides its
efficacy in APL therapy, ATRA is extensively used in the treatment of various skin
diseases such as psoriasis, skin cancer, acne, and ichthyosis. Aim: This study aimed to
assess the impact of high-dose ATRA on tibial growth by measuring serum growth
hormone “GH,” histomorphometric measurements of tibia, and histopathological
examination of tibia in young male albino rats. Methods: This experimental study included
54 male albino rats, aged 6 weeks, divided into three groups: group I and group II served
as control groups, whereas group III was administered ATRA treatment (40 mg/kg/day of
ATRA suspension administered via gavage, dissolved in 1 cc of corn oil at a concentration
of 10 mg/ml, with an oral LD50 of 2 g/kg). Each group was subdivided into three
subgroups, each comprising six rats. The research was submitted to the Research Ethics
Committee of the Faculty of Medicine at Benha University. The study assessed the effects
of ATRA treatment on serum growth hormone, weight, tibial length, nose-tail length, outer
cortical bone thickness, relative bone resorption eroded surface percentage, osteoclast
count, and osteoblast count compared to control groups. Results: There were no notable
variations in these parameters among the control groups. In addition, there were no
significant differences in osteoblast count among all groups. The ATRA-treated groups
demonstrated a significant decrease in serum growth hormone, weight, tibial length, nosetail
length, and outer thickness of cortical bone, as well as a highly significant increase in
relative bone resorption eroded surface percentage and osteoclast count.