ABSTRACT
Objective To investigate the effects of nonylphenol (NP) exposure on the activity of SOD and GSH-Px and the content of MDA in gastric tissue of SD rats. Methods Twenty-four clean SD rats were randomly divided into four groups, 6 in each group. The negative control group was given corn oil, and the exposure groups included low, medium and high doses of NP treatment groups. NP was prepared in corn oil and administrated intragastrically. The concentration of NP was 25, 50 and 100 mg/kg, respectively, given once a day. After 42 days of continuous intragastric administration, the animals were sacrificed under anesthesia and gastric tissues were collected. The pathological changes of gastric tissues were observed by HE staining. The activity of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and level of malondialdehyde (MDA) in gastric tissues were respectively detected by chemical colorimetry. Results No bleeding or necrosis was found in the gastric mucosa of all groups by naked eye view. Pinhole-sized pigmentation was found in the stomach wall fold and bulge of NP medium dose group, and the number of pigmentation spots was increased significantly in NP high dose group. HE staining showed that the epithelial cells and glands of gastric mucosa of rats in normal group were arranged neatly and intact, and no any defect or abnormality in mucosal myometrium was observed. In the low dose group, hyperemia and edema, and vasodilation in the mucosal glands were observed, while in the medium and high dose groups, the epithelial cells of the gastric mucosa were damaged and exfoliated, the glandular ducts were swollen and congested, and lymphocyte infiltration was observed in the mucosa and interstitium. Compared with the control group, SOD activity in the high dose group was significantly decreased (P0.05). SOD activity decreased gradually with the increase of the dose. Compared with the control group, there was no significant difference in GSH-Px content among the NP exposure groups. Compared with the control group, the MDA content in the low dose group was significantly increased (P<0.05), while there was no significant difference in the medium and high dose groups. Conclusion Short-term exposure to 25mg/kg nonylphenol caused oxidative damage to gastric mucosa.
ABSTRACT
Cerebrovascular disease is a common cause of cognitive impairment or dementia.Vascular cognitive impairment (VCI) often occurs independently or coexists with Alzheimer's disease and other neurodegenerative diseases.Early intervention of vascular risk factors,such as hypertension,can prevent or delay the process of VCI.MRI can only reveal the parenchymal damage from structures,but can not early identify brain tissue dysfunction or the presence of VCI.The molecular imaging techniques,such as single-photon emission computed tomography and positron emission tomography have been gradually used to the field of neuroscience.They have important roles in the diagnosis,differential diagnosis,and related research of VCI.