R Luo1, M Mao, X Xiao. 1. Department of Pediatrics, Second Affiliated Hospital, WCUMS, Chengdu 610041, China.
Abstract
OBJECTIVE: To understand the level of nerve growth factor (NGF) in the brain of rat pups in intrauterine growth retardation (IUGR), explore the mechanism of brain injury. METHODS: Animal models for IUGR pups were established by clamping the uterine vasculature of pregnant rats with 30 minutes in this study. NGF proteins were measured by immunohistochemistry in the cerebellar cortex of rat pups at birth (21 days of gestation), and on the sixth day after birth. RESULTS: 1. The body weight of the 21-day fetuses in IUGR group decreased 16.1% as compared to that in control group (P < 0.0001); 2. The brain weight of the 21-day fetuses in IUGR group decreased to that in control group (P < 0.05) development of their brain retardation during the intrauterine in IUGR fetus period in this model; 3. On the sixth day after birth, there was no statistical difference in body weight between the IUGR and the control groups. But the brain weight difference between these two groups was still there; 4. At birth and on the sixth day after birth, there were statistical differences in NGF proteins in cerebellum between the IUGR and the control groups, which got along with the decrease of their brain weights. CONCLUSION: A successful animal model of IUGR was established by clamping the uterine vasculature of pregnant rats with 30 minutes, and the development of their brain were retarded in IUGR fetus period in this model. Brain retardation in IUGR pups may relate with the decreased level of NGF in brain. This study discovered that quick "catch-up" growth in physical development and slow "catch-up" growth in brain development in IUGR pups.
OBJECTIVE: To understand the level of nerve growth factor (NGF) in the brain of rat pups in intrauterine growth retardation (IUGR), explore the mechanism of brain injury. METHODS: Animal models for IUGR pups were established by clamping the uterine vasculature of pregnant rats with 30 minutes in this study. NGF proteins were measured by immunohistochemistry in the cerebellar cortex of rat pups at birth (21 days of gestation), and on the sixth day after birth. RESULTS: 1. The body weight of the 21-day fetuses in IUGR group decreased 16.1% as compared to that in control group (P < 0.0001); 2. The brain weight of the 21-day fetuses in IUGR group decreased to that in control group (P < 0.05) development of their brain retardation during the intrauterine in IUGR fetus period in this model; 3. On the sixth day after birth, there was no statistical difference in body weight between the IUGR and the control groups. But the brain weight difference between these two groups was still there; 4. At birth and on the sixth day after birth, there were statistical differences in NGF proteins in cerebellum between the IUGR and the control groups, which got along with the decrease of their brain weights. CONCLUSION: A successful animal model of IUGR was established by clamping the uterine vasculature of pregnant rats with 30 minutes, and the development of their brain were retarded in IUGR fetus period in this model. Brain retardation in IUGR pups may relate with the decreased level of NGF in brain. This study discovered that quick "catch-up" growth in physical development and slow "catch-up" growth in brain development in IUGR pups.