ABSTRACT
Objective To investigate the expression of NLRP3 in different time point of HIBD neonatal rats and to search for critical time points and alleviate HIBD dysfunction.Methods 96 newborn rats of 7 days old were randomly divided into HIBD group(n=48) and Sham operation group(n=48).HIBD model was prepared by referring to Rice method.Brain tissue was taken after 6 h,24 h,72 h,7 d.Brain injury was detected by HE stain.The expression and distribution of NLRP3 and Caspase-1 were detected by immune fluorescence and Western blot,and IL-1β and IL-18 were detected by ELISA.Results HE staining and immunofluorescence showed that NLRP3 protein (HIBD group (0.63±0.07),Sham group(0.43±0.04)) was increased significantly since 6 h in HIBD group,and its downstream protein Caspase-1,IL-1β and IL-18 were successive activated.The results showed IL-1β (HIBD group(732.28± 108.42)pg/ml,Sham group(584.58± 36.35) pg/ml) was increased significantly since 6 h in HIBD group;Caspase-1 (HIBD group(0.67±0.09),Sham group(0.30±0.05)),IL-18 (HIBD group(683.84±31.83) pg/ml,Sham group(571.32±50.91) pg/ml) was increased significantly since 24 h in HIBD group(P＜0.05).Conclusion NLRP3 and its downstream inflammatory cytokines IL-1 β and IL-18 are up-regulated when HIBD occurs.The change of NLRP3protein expression in group HIBD is earlier than changes of neuron.NLRP3 signal may mediate and participate in the occurrence and development of HIBD.
ABSTRACT
This study was aimed to observe the effect ofRong-Shuan (RS) capsule on rodent tolerance against cerebral ischemia, hypoxia and cerebral reserve capacity, which was related to promote blood circulation and remove blood stasis. Acute cerebral ischemia and anoxia models were established by permanent left carotid artery ligation on C57 BL/6 mice and hypoxia inhalation (O2?N2 = 8?92) for 15 min. Duodenal administration of RS capsule at different doses (100, 200 or 400 mg·kg-1) or saline were given 10 min after ischemia onset. The local brain blood circulation changes and neurobehavioral function were evaluated 24 h after ischemia onset. SD rats were given RS capsule at different doses (75, 150, 300 mg·kg-1) or saline. The effect of RS capsule on improvement of microcirculation disturbance induced by high molecular dextran was observed. The results showed that compared with the sham operation group, the brain blood circulation in the model group was significantly decreased; the cerebral infarction area increased; and the behavioral score after cerebral hypoxia was significantly increased (P < 0.05, orP < 0.01). Meanwhile, after the injection of high molecular dextran among rats in the model group, the cerebral leptomeninx microcirculation was obviously slowed down at 3 timepoints, which were 10, 20 and 30 min. Compared with the model group, RS capsule (400 mg·kg-1) can significantly increase the local blood circulation in the brain of mice, improve behavioral disturbance, reduce cerebral ischemia area (P< 0.05, orP < 0.01). RS capsule can also improve blood flow velocity and flow pattern in cerebral leptomeninx microcirculation disturbance induced by high molecular dextran at different timepoints (P < 0.05, orP < 0.01). It was concluded that RS capsule can increase the tolerance against cerebral ischemia, hypoxia and cerebral reserve capacity in order to protect the neural tissues to promote neuronal recovery.