147 SKELETAL GROWTH IN HYPERGLYCEMIC FETAL RATS

It is unknown why fetal rats of diabetic mothers are smaller than normal. Therefore, pregnant rats were infused i.v. from day 19 to 21 with saline (S) or 40% Glucose (G). Fetal body weight and the thymidine incorporation into fetal a) rib cartilage in vivo and b) isolated chondrocytes in response to normal fetal or maternal rat serum were determined. Bodyweights were lower in G: 4.17 ± 0.17 g, n=18 than in S: 4.32 ± 0.14g, n=24, < 0.05. In S thymidine incorporation in vivo was higher in small compared to big fetuses: r= -0.531, n=55, < 0.001. Opposite results were obtained in group G: r= +0.542, n=54, < 0.001. The results of the thymidine incorporation into isolated chondrocytes are shown in the table (cpm/105 cells). (M ± SEM; n=12, a< 0.05; b < 0.001 versus 0% serum) Chondrocytes of hyperglycemic fetuses did not respond to maternal serum, which suggests that both adult and fetal growth factors are needed for appropriate fetal growth.