[Show abstract][Hide abstract] ABSTRACT: Studies have suggested that maternal infection/inflammation maybe a major risk factor for neurodevelopmental brain damage. In the present study, we evaluated the effects of prenatal exposure to a low level of inflammatory stimulation lipopolysaccharide (LPS) repeatedly on spatial learning and memory performances in rat offspring's lifetime. Sixteen pregnant Sprague-Dawley rats were randomly divided into two groups. The rats in the LPS group were treated i.p. with LPS (0.79 mg/kg) at gestation day 8, 10 and 12; meanwhile the rats in the control group were treated with saline. After delivery, the rat offspring at 3- (young), 10- (adult) and 20-mon-old (aged) were allocated. Spatial learning and memory abilities were tested by Morris water maze. The structure of hippocampal CA1 region was observed by light microscopy. The expression of synaptophysin (SYP) and glial fibrillary acidic protein (GFAP) in hippocampal CA1 region were measured by immunohistochemistry. Results showed that the rat offspring of LPS group needed longer escape latency and path-length in the Morris water maze and presented a significant neuron loss, decreased expression of SYP, increased expression of GFAP in CA1 region in histological studies. All these changes were more significant with the age increasing. These findings support the hypothesis that maternal systemic inflammation may alter the state of astrocytes in rat offspring for a long time, the alteration may affect neurons and synapse development in neural system, increase the neurons' vulnerability to environment especially as the age increasing, at last result in distinct learning and memory impairment.
[Show abstract][Hide abstract] ABSTRACT: To explore the temporal expression pattern of cyclooxygenase (COX)-2 and effects of panax notogensing saponins (PNS) in peritoneal macrophages of rats.
Phagocytosis function of peritoneal macrophages was measured by chicken red blood cell phagocytosis assay in vitro. Expression of COX-2 mRNA and protein, PGE(2) and PGD(2) production were determined with real-time PCR, Western blotting and radioimmunoassay, respectively.
Phagocytosis function of macrophages increased significantly after stimulation and reached peak during 2-3h. Expression of COX-2 mRNA and its protein increased markedly after stimulation and reached the first peak at 2 h and 3h, respectively; and then decreased to reach a minimum at 24h. The second peak appeared at 36h. PNS (50, 100, 200 mg/kg) increased the phagocytosis function obviously at 2h, decreased the expression level of COX-2 and PGE(2) production at 2 h and elevated COX-2 expression and PGD(2) production at 36 h, respectively.
COX-2 expression in peritoneal macrophages has a double-hump feature after stimulation. PNS enhanced phagocytosis, inhibiting COX-2 expression at an early stage and elevating it at a later stage.
Agents and Actions 03/2009; 58(2):74-80. · 2.14 Impact Factor