Roles of sympathicus, sensory neuropeptides (SNP), metabolites of cyclooxygenase, metabolites of lipoxygenase, endothelium derived relaxing factor (EDRF), reactive oxygen (ROS) and potassium channels (PC) in the hypoxic pulmonary vasoconstriction (HPV) and hypoxic cerebral vasodilation (HCVD) were studied in intact rats, rabbits and dogs. Results were as follows: during hypoxia, the excitation of sympathicus results in a constriction of both pulmonary and cerebral vessels; SNP, EDRF and the opening of 4-AP sensitive PC caused the dilation of both of them; metabolites of lipoxygenase mediated HPV and HCVD, whereas metabolites of cyclooxygenase were their modulators; hypoxia induced blockade of the ATP sensitive PC mediated HPV, but had no effect on HCVD; reduction of O_2~+ in the lung might potentiate HPV, but had no effect on HCVD. It is suggested that the alteration of lipoxygenase metabolites, ROS and ATP sensitive PC are factors accounting for the difference in response of pulmonary and cerebral vassels to hypoxia.

Background:TLR4/NF-κB signaling pathway is involved in the tumorigenesis of a variety of malignancies via multiple mechanisms. However,its role in gastric cancer is not clearly clarified yet. Aims:To investigate the expressions of molecules in TLR4/NF-κB signaling pathway and their correlations with the clinicopathological characteristics of gastric cancer. Methods:A total of 154 endoscopic or surgical specimens of gastric cancer were collected at the Xijing Hospital of Digestive Diseases,the Fourth Military Medical University from Jan. 2014 to Oct. 2016 and were categorized into Helicobacter pylori(Hp)-positive group and Hp-negative group according to the status of Hp infection. Expressions of TLR4,MyD88 and NF-κB mRNA in gastric cancer tissues were detected by real-time PCR. Results:In Hp-positive group,expression levels of TLR4,MyD88 and NF-κB mRNA in gastric cancer tissues were significantly higher than those in Hp-negative group(P <0.05). Furthermore,it was found that the expression levels of TLR4,MyD88 and NF-κB mRNA in patients with poorly differentiated or undifferentiated cancer,with distant metastasis and in TNM stageⅢ-Ⅳwere significantly higher than those in patients with well-to-moderately differentiated cancer,without distant metastasis and in TNM stage Ⅰ-Ⅱ,respectively(P all <0.05). Spearman correlation coefficient analysis revealed that the expression levels of TLR4,MyD88 and NF-κB mRNA were positively correlated with each other in gastric cancer tissues(r=0.734 for TLR4 and MyD88,r =0. 657 for TLR4 and NF-κB,and r = 0. 828 for MyD88 and NF-κB,P all < 0. 05). Conclusions:TLR4/NF-κB signaling pathway is implicated in the tumorigenesis of Hp infection-related gastric cancer. In gastric cancer tissues,TLR4/NF-κB signaling pathway might be associated with the malignant behavior of tumor and promote tumor progression.