Long-term Effects Of Maternal Nutrition On Offspring Rats And Potential Mechanism

Section 1 Long-term effects of maternal nutrition on offspring ratsObjective:This study was designed to examine the long-term effects of prenatal protein malnutrition on growth and development,learning and memory abilities, blood pressure and plasma glucose level of offspring rats during adolescence and adulthood.Study design:Maternal rats were randomly divided into three groups:(1) low-protein group,which received a 7%of protein diet,(2) high-protein group,which received a 30%of protein diet,and(3) a control group that received an 18%of protein diet.The offspring rats of these groups were tested for visual-spatial learning and memory abilities in Morris water maze performed on postnatal 8th week and 1 year,which divided into two parts.In the four days' behavior training,rats were trained in a Morris pool to find a hidden platform located some distance away.In the second part--the test trials were performed without the platform.And body weight,blood pressure and plasma glucose were also measured in the offspring rats of the low-protein and the control groups at the age of 100 days,120 days,150 days,180 days and 1 year.Results:(1) The birth weight of the offspring rats in the low-protein group was lower than that in the control group by 22.50%.There is not obvious difference of the postnatal body weight between the two groups' offspring rats.(2) In Morris water maze test,two different patterns of learning and memory were implied.Unlike the control group which learned to swim to the platform gradually at a constant speed,the low- and high-protein group learned faster then cut the speed down during adolescence.However prolonged latency was found in one-year-old female rats in the low-protein group.(3) The adult rats in the low-protein group did not have high blood pressure.(4) The plasma glucose level tested in the low-protein group was higher than the counterpart of the control group.Conclusion:Our study demonstrates that maternal malnutrition like prenatal protein malnutrition results in FGR,and offspring shows catch-up growth in their childhood. Prenatal malnutrition can cause gender- and age-specific impairment of spatial learning and memory abilities to the offspring.It also has impact on the offspring's plasma glucose level.Section 2 Mechanism of maternal nutrition's long-term effects on offspring ratsObjective:To explore the mechanism of the long-term effects of prenatal protein malnutrition on offspring rats' health during adolescence and adulthood.Study design:Maternal rats were randomly divided into three groups:(1) low-protein group,which received a 7%of protein diet,(2) high-protein group,which received a 30%of protein diet,and(3) a control group that received an 18%of protein diet. Cesarean section was performed in pregnant day 21.The corticosterone,ACTH and insulin levels were analyzed by ELISA in maternal and offspring rats.And histiocyte morphology of main organs e.g.cerebra,liver,adrenal were observed.Results:Compared with the offspring rats in control group,the corticosterone,ACTH and insulin levels of counterparts in low-protein group decreased.Histiocyte morphology changes were observed in cerebra,adrenal,liver in low- and high-protein offspring rats.Conclusion:Unfavorable intrauterine nutrition environment makes the fetus develop adaptive changes,impacting the development of main organs,resulting in rebuilding of many endocrine systems of the fetus,which directly determine development of adult diseases.