[Animal Modeling]-Correlation between obesity and early youth development in female juvenile SD rats

  Objective: To explore the correlation between obesity and female juvenile SD rats and early youth development.

  Methods: 10 female SD rats and 6 male SD rats were randomly divided into two groups, namely the parental model group (female rats n=5, male rats n=3) and the parental control group (female rats n=5). , Male rats n=3). The model group was fed with high-fat feed for 8 weeks to build a model, and the control group was fed with ordinary rat feed. After 8 weeks, the parent rats of the model group with a body mass greater than 20% of the control group were selected for mating, and the female pups to be reproduced were set The pups of the model group, female pups bred from the parental control group were used as the control pups. The modeling method of the model group's pups is the same as that of the model group's parent rats. They are all fed with the same formula high-fat diet. They are fed for 5 weeks after weaning at 21 days, and the control pups are fed with ordinary diet for 5 weeks. From the 21st day of age, observe the opening of the vulva of the offspring every day. After the vulva is opened, vaginal smears are performed every day to observe the estrus cycle, and weigh the weight; the measurement of body length and abdominal circumference is performed once every two weeks; two The experimental pups of the group of experimental mice all ended the experiment at the age of 56 days, and blood was taken from the abdominal aorta. Generating hormone (LH), estradiol (E2). After the experiment, the 56-day-old pups were dissected, the uterus and ovaries were taken, and the ovarian index and uterine index were calculated. The uterus and ovaries were pathologically sectioned for HE staining, and the number of the corpus luteum and the number of mature eggs in the largest cross-section of the ovary were counted.

  Results: ①At the end of the 56-day-old model, the weight and abdominal circumference of the pups in the model group were higher than those in the control group, P<0.001; ②The serum TG and CH of the pups in the model group were higher than those in the control group, P<0.001; ③Model The serum LH and E2 concentrations of pups in the group were higher than those of the control group, P<0.001, and the serum FSH concentration was lower than that of the control group, P<0.001; ④The maximum cross-sectional corpus luteum counts in the ovarian pathological sections of the pups in the model group were higher than those in the control group. P<0.001; The count of mature follicles is less than that of the control group, P<0.001; ⑤The results of Pearson correlation analysis are: the weight of young SD rats is negatively correlated with the first estrus interval and the time of opening the vulva. Serum LH and corpus luteum count in the largest cross-section of the ovary are positively correlated; the abdominal circumference of young SD rats is negatively correlated with the time of the first estrus interval and the opening time of the vulva, which is correlated with serum LH and the largest ovarian cross-section. There is a positive correlation between the two indexes of luteal count in cross-section slices.

  Conclusion: Judging indicators of juvenile development of young SD rats are correlated with obesity indicators, and are positively correlated. That is to say, the youthful development of young SD rats with obesity characteristics is earlier than that of normal control young rats.