Disproportional skeletal growth and markedly decreased bone mineral content in growth hormone receptor -/- mice

Growth hormone (GH) is important for skeletal growth as well as for a norma l bone metabolism in adults. The skeletal growth and adult bone metabolism was studied in mice with an inactivated growth hormone receptor (GHR) gene, The lengths of femur, tibia, and crown-rump were, as expected, decreased i n GHR-/- mice. Unexpectedly, GHR-/- mice displayed disproportional skeletal growth reflected by decreased femur/crown-rump and femur/tibia ratios. GHR -/- mice demonstrated decreased width of the growth plates in the long bone s and disturbed ossification of the proximal tibial epiphysis. Furthermore, the area bone mineral density (BMD) as well as the bone mineral content (B MC)/body weight were markedly decreased in GHR-/- mice. The decrease in BMC in GHR-/- mice was not due to decreased trabecular volumetric BMD but to a decreased cross-sectional cortical bone area In conclusion, GHR-/- mice de monstrate disproportional skeletal growth and markedly decreased bone miner al content, (C) 2000 academic Press.