Tensile strength and trabecular parameter disturbances at 12 weeks postnatally in Sprague Dawley rats exposed to gestational alcohol

Abstract

Gestational alcohol exposure impairs bone growth and may cause an increase in osteoporosis and fracture risk later in life. The study aimed to investigate how intrauterine alcohol exposure would impede trabecular morphometric parameters and tensile strength in postnatal 12-weekold rats. Time-mated (n=10) pregnant rats were assigned to an ethanol experimental group (n=5) and a saline control group treated with 0.015ml/g of 25.2% ethanol or 0.9% saline for the initial 19 days of pregnancy through oral gavage, respectively. Two pups from each dam were used, and terminated when aged 12-weeks, and ten paired humerus bones and femora obtained per group. The bones were scanned at 20µm resolution. Bone length, the bone volume to total volume ratio (BV/TV), trabecular thickness (TbTh), number (TbN), and spacing (TbSp) were analysed as well as cortical bone architecture. Then, 3-point bending tests were conducted with a universal tensile tester to obtain the maximum force, displacement, and time, as well as the breaking force. Both the humerus and the femur were shorter in the experimental group (ethanol) with a smaller bone fraction area, fewer trabecular that were more widely spaced in both proximal and distal regions although trabecular thickness was similar in both the ethanol and control (saline) groups. Tensile strength revealed group similarities. Therefore, the effects of gestational alcohol exposure were not severe at 12 weeks of age, this may suggest that there is potential skeletal recovery in adult life following intrauterine alcohol exposure. However, gestational alcohol affected trabecular morphometric parameters at 12 weeks of age.