Analysis of Content Characteristics of Partial Biochemical Substances in Peripheral Blood of Autism Spectrum Disorder...

To observe the content characteristics and variation rules of partial biochemical substances in peripheral blood of autism model rats at different weeks of age.

This was an experimental study. Time-mated female Sprague-Dawley (SD) rats were given a single intraperitoneal injection of 600 mg/kg valproic acid (VPA) and 20 mg/kg polyinosinic:polycytidylic acid (poly I:C) on gestational day 12.5. Offspring rats were screened as autism model rats through behavioural tests including stereotypic behaviour assessment, marble burying test and three-chamber social interaction test. A total of 12 autism model rats (six males and six females) were selected as the experimental group, and 12 normal rats (six males and six females) were selected as the control group. Periorbital venous blood samples were collected at 2, 4, 6 and 8 weeks of age, respectively. Enzyme-linked immunosorbent assay (ELISA) was used to detect the levels of brain-derived neurotrophic factor (BDNF), glutathione (GSH), neurotrophin-3 (NT3), neurotrophin-4 (NT4), interleukin-6 (IL-6) and serotonin (5-HT) in peripheral blood. The content characteristics of the aforementioned biochemical substances between the experimental group and the control group, as well as the dynamic changes in blood test results of rats at different weeks of age, were compared.

At 2 and 4 weeks of age, the levels of BDNF, NT3, NT4, IL-6 and 5-HT in peripheral blood of autism model rats were significantly higher, whereas the level of GSH was significantly lower than those of normal rats (p < 0.05). At 6 weeks of age, the level of IL-6 was significantly higher and the level of GSH was significantly lower in the experimental group than in the control group (p < 0.05), whereas there were no significant differences in BDNF, NT3, NT4 and 5-HT levels between the two groups (p > 0.05). At 8 weeks of age, the levels of BDNF, NT3, NT4, GSH and 5-HT in the experimental group were significantly lower, whereas the level of IL-6 was significantly higher than those in the control group (p < 0.05). No significant differences were found in the levels of the aforementioned substances between male and female rats within both groups (p > 0.05).

With the increase of age, the levels of BDNF, NT3, NT4 and 5-HT in peripheral blood of autism model rats gradually decrease to the level of normal rats and eventually become lower than those of normal rats. The level of IL-6 remains high and the level of GSH remains low throughout the whole life cycle of autism model rats. The dynamic changes and status of these factors in peripheral blood may provide certain references for the blood research of children with autism spectrum disorder.