The actions,detection and synthesis of platelet-activating factor (PAF) in mammalian pregnancy

Platelet-activating factor (PAF) exhibits a variety of biological activities and it be thought to involved in various pathophysiological process. In this paper, some studies were summarized about those roles ofPAF in a variety productive processes of female of mammalian that inctude fertilization, implantation and parturition, and that was involved in the concentration, synthesis, deiradation and some assay methods of PAF. Therelationship between PAF and early pregnancy factor (EPF) was reviewed.

Lipopolysaccharide-induced cerebral inflammatory damage and the therapeutic effect of platelet activating factor receptor antoganist

Objective To investigate lipopolysaccharide （LPS） induced acute cerebral inflammatory damage and the therapeutic effect of ginkgolide B （BN52021）. Methods Thirty Sprague-Dawley rats were randomly divided into 3 groups （n = 10 for each group）： Control group, Model group and Treatment group （treated with BN52021）. LPS were injected into the fourth ventricle of rat to make a neuroinflammatory murine model. Morris water maze was used to detect the learning and memory ability of rats; changes of synapse number and subcellular ultrastructures were observed under a transmission electron microscope; OX-42 positive microglia in the brain was detected by immunohistochemical method. Results The average escape latency in the Treatment group were significantly shortened than that in the Model group; and the percentage of swimming distance traveled in platform quadrant accounting for total distance increased markedly. The rough endoplasmic reticulum and polyribosomes in the Treatment group were more than that in the Model group, but the number of synapses seemed to have no obvious change. The number of OX-42 positive microglia in the Treatment group decreased markedly than that in the Model group, and the grey density of OX-42-positive cells increased significantly. Conclusion LPS can induce inflammatory damages to the brain, but the damage could be antagonized by BN52021. Platelet activating factor receptor antagonist may offer an effective therapy for neurodegeneration diseases.

ABCD2评分、PAF、sCD40L、C1q对短暂性脑缺血发作后脑梗死的预测价值及其危险因素分析

目的探讨ABCD2评分及血清血小板活化因子(PAF)、可溶性CD40配体(sCD40L)、补体1q(C1q)对短暂性脑缺血发作后脑梗死的预测价值。方法回顾性选取2020年11月至2022年12月该院收治的94例短暂性脑缺血发作后脑梗死患者作为脑梗死组,另选取同期收治的146例短暂性脑缺血发作后非脑梗死患者作为非脑梗死组。比较两组临床资料,采用多因素Logistic回归分析短暂性脑缺血发作后脑梗死的危险因素,并绘制受试者工作特征(ROC)曲线分析ABCD2评分及血清PAF、sCD40L、C1q单独及联合检测对短暂性脑缺血发作后脑梗死的预测价值。结果脑梗死组和非脑梗死组颈部血管斑块、发作持续时间、发作频率情况,ABCD2评分及血清PAF、sCD40L、C1q、白细胞介素(IL)-6、超敏C反应蛋白(hs-CRP)水平比较,差异均有统计学意义(P<0.05)。多因素Logistic回归分析结果显示,有颈部血管斑块、发作持续时间≥15 min、发作频率≥2次/月,以及ABCD2评分,血清PAF、sCD40L、C1q、IL-6、hs-CRP水平升高是短暂性脑缺血发作后脑梗死的独立危险因素(P<0.05)。ROC曲线分析结果显示,ABCD2评分及血清PAF、sCD40L、C1q联合预测短暂性脑缺血发作后脑梗死的灵敏度、曲线下面积分别为96.81%、0.927,高于或大于ABCD2评分及血清PAF、sCD40L、C1q单独预测(P<0.05);ABCD2评分、血清PAF单独预测的灵敏度分别高于血清sCD40L、C1q单独预测的灵敏度(P<0.05);ABCD2评分及血清PAF、sCD40L单独预测的特异度高于血清C1q单独、4项指标联合预测的特异度(P<0.05),血清C1q单独预测的特异度高于4项指标联合预测的特异度(P<0.05)。结论短暂性脑缺血发作后脑梗死的发生与患者有颈部血管斑块、发作持续时间≥15 min、发作频率≥2次/月,以及ABCD2评分,血清PAF、sCD40L、C1q、IL-6、hs-CRP水平升高均密切相关,且ABCD2评分及血清PAF、sCD40L、C1q联合检测对短暂性脑缺血发作后脑梗死的预测价值更高。

AMI患者PCI术后血清PAF、CK-MB、sCD40L水平变化及其与再缺血的关系

目的探究急性心肌梗死(AMI)患者经皮冠状动脉介入(PCI)术后血清血小板活化因子(PAF)、肌酸激酶同工酶(CK-MB)、可溶性白细胞分化抗原40配体(sCD40L)水平的变化,并分析其与术后再缺血的关系。方法前瞻性选取2019年10月至2022年10月郑州大学第一附属医院收治的225例AMI患者作为研究对象,检测围手术期(术前、术后3 d、术后14 d)所有患者的血清PAF、CK-MB、sCD40L水平,术后接受为期1年随访,根据PCI术后有无再缺血发生分为再缺血发生组30例和再缺血未发生组195例。比较两组患者的临床资料及血清PAF、CK-MB、sCD40L水平;采用Logistic回归方程分析AMI患者PCI术后再缺血影响因素;绘制受试者工作特征曲线(ROC)分析血清PAF、CK-MB、sCD40L水平对AMI患者PCI术后再缺血的预测价值。结果再缺血发生组患者的中国冠心病患者抗血小板治疗优选方案(OPT-CAD)评分为(102.41±15.83)分,明显高于再缺血未发生组的(82.37±10.69)分,差异有统计学意义(P<0.05);再缺血发生组患者术后3 d、14 d的血清PAF水平分别为(89.15±20.11)ng/mL、(78.60±13.24)ng/mL,明显高于再缺血未发生组的(79.85±17.69)ng/mL、(67.42±10.38)ng/mL,CK-MB水平分别为(38.28±11.94)μg/L、(23.09±6.83)μg/L,明显高于再缺血未发生组的(34.83±10.16)μg/L、(17.69±5.12)μg/L,sCD40L水平分别为(4681.69±305.63)pg/mL、(3721.59±175.63)pg/mL,明显高于再缺血未发生组的(4369.39±227.84)pg/mL、(3129.46±132.88)pg/mL,差异均有统计学意义(P<0.05);经Logistic回归方程分析结果显示,OPT-CAD评分及术后3 d、14 d血清PAF、CK-MB、sCD40L水平均为AMI患者PCI术后再缺血发生的危险因素(P<0.05);经ROC分析结果显示,术后3 d血清PAF、CK-MB、sCD40L联合预测再缺血发生的AUC为0.877,术后14 d血清PAF、CK-MB、sCD40L联合预测再缺血发生的AUC为0.930,均大于各时间点三项血清指标单独预测。结论血清PAF、CK-MB、sCD40L水平是AMI患者PCI术后再缺血发生的危险因素,围手术期血清PAF、CK-MB、sCD40L联合预测患者PCI术后再缺血风险的效能较高,可为临床防治PCI术后再缺血提供参考。

慢性荨麻疹患者血清PAF、抗-CCD IgE水平变化及临床意义分析

目的探讨慢性荨麻疹患者血清血小板活化因子(platelet activating factor,PAF)、抗交叉反应性糖类决定簇免疫球蛋白E(anti-cross reactive carbohydrate determinants immunoglobulin E,抗-CCD IgE)水平变化及临床意义,为临床诊断及病情程度、预后评估提供参考依据。方法选取2021年5月—2023年5月广州市皮肤病防治所收治的100例慢性荨麻疹患者,根据荨麻疹活动评分分为轻度组(n=41)、中度组(n=35)和重度组(n=24)。采集患者空腹静脉血,通过酶联免疫吸附法测定血清PAF水平,通过斑点免疫印迹法测定抗-CCD IgE、过敏原特异性免疫球蛋白E(specific immunoglobulin E,sIgE)。比较不同病情程度慢性荨麻疹患者血清PAF水平,分析慢性荨麻疹患者血清PAF水平与荨麻疹活动评分相关性,比较不同临床特征慢性荨麻疹患者抗-CCD IgE阳性率。结果中度组、重度组患者血清PAF水平高于轻度组,重度组患者血清PAF水平高于中度组,差异有统计学意义(P<0.05)。Pearson相关分析结果显示,慢性荨麻疹患者血清PAF水平与荨麻疹活动评分呈正相关性(r=0.491,P<0.001)。年龄≥45岁、重度病情、sIgE阳性患者抗-CCD IgE阳性率高于年龄<45岁、轻度病情、sIgE阴性患者,差异有统计学意义(P<0.05)。抗-CCD IgE阳性患者中过敏原阳性最高的为尘螨组合(66.67%),其次为蟑螂、螃蟹、普通豚草,分别为55.56%、44.44%和44.44%。结论慢性荨麻疹患者血清PAF水平与病情密切相关,且抗-CCD IgE水平与sIgE水平有一定关系,抗-CCD IgE阳性表达情况对sIgE试验存在一定干扰,分析试验结果时应考虑抗-CCD IgE的影响。

Elevated Platelet Activating Factor Level in Ischemia-Related Arrhythmia and Its Electrophysiological Effect on Myocardium

Objective The mechanism through which platelet activating factor （PAF） induces cardiac electrical activity and arrhythmia is not well understood and previous studies have suggested a potential involvement of ion channels in its action. The present study was aimed to clarify the role of PAF in fatal arrhythmias following acute myocardia infarction （AMI） and the underlying mechanism. Methods （1） Blood PAF levels were measured among 72 AMI patients at the time of diagnosis with AMI and 48 h later, and their electrocardiogram （ECG） was recorded continuously. （2） Ischemia simulation and surface electrocardiogram were conducted in 20 pigs and their PAF levels were measured. （3） PAF perfusion and standard microelectrode recording were performed on guinea pig papillarymuscles. Results In both humans and pigs, elevated PAF levels were detected in AMI and simulated ischemia, respectively, and even higher PAF levels were found when fatal arrhythmias occurred. In guinea pig myocardium, PAF induced a shortening of action potential duration at 90% level of repolarization （APD 90 ）under non-ischemic conditions and a more pronounced shortening under early simulated ischemic conditions. Conclusion AMI and ischemia are associated with increased PAF levels in humans and pigs, which are further raised when fatal arrhythmia follows. The effects of PAF on the myocardium may be mediated by multiple ion channels.

Effect of increased hepatic platelet activating factor and its receptor portal hypertension in CCl_4-induced liver cirrhosis

AIM： To evaluate the changes in hepatic platelet activating factor （PAF） and its receptors and their effect on portal pressure of cirrhotic rats induced by CCh. METHODS： A model of liver cirrhosis was replicated in rats by intra-peritoneal injection of CCh for 8 wk. We determined the effect of hepatic PAF and its receptor level on portal and arterial pressure by EIA, saturation binding and RT-PCR technique. RESULTS： Compared to control rats, cirrhotic rats had higher hepatic PAF levels and output as well as higher plasma PAF levels （P〈0.01, P〈0.01, P〈0.05, respectively）. Both hepatic PAF receptor mRNA levels and PAF binding were nearly 3-fold greater in cirrhotic rats （P〈0.01）. Portal injection of PAF （1 g/kg WT） increased the portal pressure by 22% and 33% in control and cirrhotic rats, respectively. In contrast, the arterial pressure was decreased in the both groups （54% in control rats and 42% in cirrhotic rats）. Injection of the PAF antagonist BN52021 （5 mg/kg WT） decreased the portal pressure by 16% in cirrhotic rats but had no effect in the control rats. CONCLUSION： The upregulation of the PAF system contributes to hepatic hemodynamic and metabolic abnormalities in drrhosis, and the increased release of PAF into the circulation has impacts on the systemic hemodynamics.

Significance of platelet activating factor receptor expression in pancreatic tissues of rats with severe acute pancreatitis and effects of BN52021

AIM:To investigate the dynamic changes and significance of platelet activating factor receptor (PAF-R) mRNA and protein in pancreatic tissues of rats with severe acute pancreatitis (SAP) and effects of BN52021 (Ginkgolide B). METHODS:Wistar male rats were randomly assigned to the negative control group (NC group),SAP model group (SAP group),and BN52051-remedy group (BN group),and each of the groups was divided into 6 subgroups at different time points after operation (1 h,2 h,3 h,6 h,12 h,and 24 h) (n=10 in each). PT-PCR and Western blot methods were used to detect PAF-RmRNA and protein expression in pancreatic tissues of rats respectively. Pathological examination of pancreatic tissues was performed and the serum amylase change was detected. RESULTS:Serum amylase and pathological results showed the that SAP model was successfully prepared,BN52021 was able to decrease serum amylase,and the pathological ratings in BN group at 3 h,6 h,and 12 h significantly decreased compared with those in the SAP group (8.85 ± 0.39 vs 5.95 ± 0.19,9.15 ± 0.55 vs 5.55 ± 0.36,10.10 ± 0.65 vs 6.72 ± 0.30,P < 0.05). The result of PAF-mRNA showed dynamic changes in SAP and BN groups,which increased gradually in early stage,reached a peak at 3 h (0.71 ± 0.14 vs 0.54 ± 0.14,0.69 ± 0.13 vs 0.59 ± 0.04,P < 0.05),and decreased gradually later. There were significant differences at each time point except 1 h and 2 h,when compared with those in the NC group (0.71 ± 0.14 or 0.69 ± 0.13 vs 0.47 ± 0.10,0.38 ± 0.08 or 0.59 ± 0.04 vs 0.47 ± 0.09,0.25 ± 0.07 or 0.29 ± 0.05 vs 0.46 ± 0.10,0.20 ± 0.06 or 0.20± 0.04 vs 0.43 ± 0.09,P < 0.05),whereas there was no significant difference between BN and SAP groups at each time point. The result of PAF-R protein showed that the change of PAF-R protein in the SAP group and the BN group was consistent with that of PAF-R mRNA. There were significant differences at each time point except 1 h,when compared with those in the NC group (0.90 ± 0.02 or 0.80 ± 0.05 vs 0.48 ± 0.02,1.69 ± 0.06 or 1.58 ± 0.02 vs 0.48 ± 0.03,1.12 ± 0.10 or 0.98 ± 0.03 vs 0.49 ± 0.09,1.04 ± 0.14 or 0.87 ± 0.02 vs 0.52 ± 0.08,0.97 ± 0.16 or 0.90 ± 0.05 vs 0.49 ± 0.10,P < 0.05),whereas there was no significant difference between the BN group and the SAP group. CONCLUSION:PAF-R plays an important role in occurrence and development of SAP. BN52021 exerts biological effects through competitively inhibiting the binding of increased both PAF and PAF-R expression rather than through decreasing PAF-R expression in pancreatic tissues.

Platelet-activating factor in cirrhotic liver and hepatocellular carcinoma

AIM： Platelet-activating factor （PAF） is a pro-inflammatory and angiogenic lipid mediator. Here we aimed to investigate levels of PAF, lyso-PAF （the PAF precursor）, phospholipase A2 （PLA2, the enzymatic activity generating lyso-PAF）, acetylhydrolase activity （AHA, the PAF degrading enzyme） and PAF receptor （PAF-R） transcripts in cirrhotic liver and hepatocellular carcinoma （HCC）. METHODS： Twenty-nine patients with HCC were enrolled in this study. Cirrhosis was present in fourteen patients and seven had no liver disease. Tissue PAF levels were investigated by a platelet-aggregation assay. Lyso- PAF was assessed after its chemical acetylation into PAR AHA was determined by degradation of [^3H]-PAE PLA2 levels were assessed by EIA. PAF-R transcripts were investigated using RT-PCR. RESULTS： Elevated amounts of PAF and PAF-R transcripts 1 （leukocyte-type） were found in cirrhotic tissues as compared with non-cirrhotic ones. Higher amounts of PAF and PAF-R transcripts 1 and 2 （tissue-type） were found in HCC tissues as compared with non-tumor tissues. PLA2, lyso-PAF and AHA levels were not changed in cirrhotic tissues and HCC. CONCLUSION： While the role of PAF is currently unknown in liver physiology, this study suggests its potential involvement in the inflammatory network found in the cirrhotic liver and in the angiogenic response during HCC.

Synthesis of platelet-activating factor and its receptor expression in Kupffer cells in rat carbon tetrachloride-induced cirrhosis

AIM:To determine the platelet-activating factor (PAF) synthesis and its receptor expression in Kupffer cells in rat carbon tetrachloride-induced cirrhosis. METHODS:Kupffer cells, isolated from the livers of control and CCl4-induced cirrhotic rats, were placed in serum-free medium overnight. PAF saturation binding, ET-1 saturation and competition binding were assayed. ET-1 induced PAF synthesis, mRNA expression of PAF, preproendothelin-1, endothelin A (ETA) and endothelin B (ETB) receptors were also determined. RESULTS:A two-fold increase of PAF synthesis (1.42 ± 0.14 vs 0.66 ± 0.04 pg/μg DNA) and a 1.48-fold increase of membrane-bound PAF (1.02 ± 0.06 vs 0.69 ± 0.07 pg/μg DNA) were observed in activated Kupffer cells of cirrhotic rats. The application of ET-1 to Kupffer cells induced PAF synthesis in a concentration-dependent manner in both cirrhotic and normal rats via ETB receptor, but PAF synthesis in the activated Kupffer cells was more effective than that in the normal Kupffer cells. In activated Kupffer cells, PAF receptor expression and PAF binding capacity were markedly enhanced. Activated Kupffer cells raised the [125I]-ET-1 binding capacity, but changed neither the affinity of the receptors, nor the expression of ETA receptor. CONCLUSION:Kupffer cells in the course of CCl4-induced cirrhosis are the main source of increased PAF. ET-1 is involved endogenously in stimulating the PAF synthesis in activated Kupffer cells via ETB receptor by paracrine. ETA receptor did not appear in activated Kupffer cells, which may exacerbate the hepatic and extrahepatic complications of cirrhosis.

Effect of Buyang Huanwu Decoction on Platelet Activating Factor Content in Arterial Blood Preand Post-Arterial Thrombosis in Rats

To explore the effect of Buyang Huanwu Decoction (BHD) on platelet activating factor (PAF) content in arterial blood pre- and post-arterial thrombosis in rats, male Wistar rats were randomly divided into 3 groups, the medicine group treated with BHD, the control group with dexamethasone liquid, and the blank group with distilled water. Oral administration was given for 14 consecutive days, once daily. Model of arterial thrombosis was established in the animals 2 hours after final medication, the blood content of PAF, dry weight (DW) and occlusion time (OT) of thrombus, and dry weight of thrombus/body weight (TW/BW) ratio were observed. Results indicated that BHD could markedly lower the arterial blood content of PAF after thrombosis, increase the OT of thrombus, reduce the dry weight of thrombus and the TW/BW ratio (P

Pathogenetic effects of platelet activating factor on enterogenic endotoxemia after burn

INTRODUCTION Previous clinical and experimental studies haveindicated that an early endotoxemia occurred after amajor burn.It is unlikely that burn wound sepsis isthe source of circulating endotoxin in less than 12hour after burn.Increasing evidence demonstratesthat the bacteria and endotoxin in thegastrointestinal tract can pass through the gutbarrier into blood circulation to form enterogenicendotoxemia following burn.However。

Sequential expression of cyclooxygenase-2, glutamate receptor-2, and platelet activating factor receptor in rat hippocampal neurons after fluid percussion injury

Traumatic brain injury causes gene expression changes in different brain regions. Occurrence and development of traumatic brain injury are closely related, involving expression of three factors, namely cyclooxygenase-2, glutamate receptor-2, and platelet activating factor receptor. However, little is known about the correlation of these three factors and brain neuronal injury. In this study, primary cultured rat hippocampal neurons were subjected to fluid percussion injury according to Scott’s method, with some modifications. RT-PCR and semi-quantitative immunocytochemical staining was used to measure the expression levels of cyclooxygenase-2, glutamate receptor-2, and platelet activating factor receptor. Our results found that cyclooxygenase-2 expression were firstly increased post-injury, and then decreased. Both mRNA and protein expression levels reached peaks at 8 and 12 hours post-injury, respectively. Similar sequential changes in glutamate receptor 2 were observed, with highest levels mRNA and protein expression at 8 and 12 hours post-injury respectively. On the contrary, the expressions of platelet activating factor receptor were firstly decreased post-injury, and then increased. Both mRNA and protein expression levels reached the lowest levels at 8 and 12 hours post-injury, respectively. Totally, our findings suggest that these three factors are involved in occurrence and development of hippocampal neuronal injury.

Hepatic stellate cells may be potential effectors of platelet activating factor induced portal hypertension

AIM: To determine platelet activating factor (PAF) receptor expression in cirrhotic hepatic stellate cells.METHODS: Hepatic stellate cells, isolated from the livers of control and CCl4-induced cirrhotic rats, were placed in serum-free medium after overnight culture. We determined the PAF receptor in hepatic stellate cells by saturation binding technique and semiquantitative reverse transcriptase polymerase chain reaction (RT-PCR), and the effects of PAF and its antagonist BN52021 on prostaglandin E2 (PGE2) release by stellate cells.RESULTS: Scatchard analysis indicated the presence of PAF receptor with dissociation constant (Kd) of 4.66 nmol/L and maximum binding capacity (Bmax) of 24.65 fmol/μg in cirrhotic stellate cells. Compared with the control, the maximum PAF binding capacity increased significantly (Bmax: 24.65 ± 1.96 fmol/μg. DNA, R = 0.982 vs 5.74 ± 1.55 fmol/μg. DNA, R = 0.93; P < 0.01), whereas receptor affinity had no significant difference (Kd of 4.66 ± 0.33 nmol/L for the cirrhosis and 3.51 ± 0.26 nmol/L for the control; P > 0.05). Consistent with the receptor binding data, the mRNA expression of PAF receptor was increased significantly in cirrhotic stellate cells. PAF in a concentration-dependent manner induced PGE2 synthesis in cirrhotic hepatic stellate cells, but the effects were blocked significantly by BN52021.CONCLUSION: Cirrhosis sensitizes hepatic stellate cells to PAF by elevating its receptor level and hepatic stellate cells maybe potential effectors of PAF induced portal hypertension.

Role of platelet-activating factor in reproduction:sperm function

Since its discovery nearly thirty years ago, platelet-activating factor has emerged as one of the more important lipidmediators known. Platelet-activating factor (PAF; 1-O-alkyl-2-O-acetyl-sn-glycero-3-phosphorylcholine) exists en-dogenously as a mixture of molecular species with structural variants of the alkyl moiety. PAF is a novel potent signal-ing phospholipid that has unique pleiotropic biological properties in addition to platelet activation. PAF also plays a sig-nificant role in reproduction. PAF content in squirrel monkey sperm is significantly higher during the breeding seasonthan the non-breeding season. PAF content in human sperm has a positive correlation with seminal parameters and preg-nancy outcomes. High-fertility boars have significantly more PAF in their sperm than low-fertility boars. The enzymes(lyso-PAF-acetyltransferase and PAF-acetylhydrolase) necessary for PAF activation and deactivation are present insperm. PAF-acetylhydrolase may act as a 'decapacitation factor'. Removal of this enzyme during capacitation maypromote PAF synthesis increasing motility and fertilization. PAF also plays a significant role in the fertilization process,enhancing the fertilization rates of oocytes. Enhanced embryo development has also been reported in oocytes fertilizedwith PAF-treated sperm. PAF antagonists inhibit sperm motility, acrosome reaction, and fertilization, thus suggestingthe presence of receptors for PAF. The PAF-receptor is present on sperm, with altered transcript levels and distributionpatterns on abnormal cells. Whereas the exact mechanism of PAF in sperm function and reproduction is uncertain, itsimportance in normal fertility is substantial. The reproductive significance of PAF activity in sperm and fertility plus therole of PAF in the establishment of pregnancy requires further study.

Creation of reversed phase high-performance liquid chromatographic technique to assay platelet-activating factor

Objective: To establish a new assay for platelet-activating factor (PAF), to compare it with bio-assay; and to discuss its significance in some elderly people diseases such as cerebral infarction and coronary heart disease. Methods: To measure PAF levels in 100 controls, 23 elderly patients with cerebral infarction and 65 cases with coronary heart disease by reversed phase high-performance liquid chromatographic technique (rHPLC). Results:rHPLC is more convenient, sensitive,specific, and less confusing, compared with bio-assay. The level of plasma PAF in patients with cerebral infarction was higher than that in the controls (P<0.01), and in patients with coronary heart disease. Conclusion: Detection of PAF with rHPLC is more reliable and more accurate. The new assay has important significance in PAF research.

Roles of BN52021 in platelet-activating factor pathway in inflammatory MS1 cells

AIM: To determine the effects of BN52021 on platelet-activating factor receptor (PAFR) signaling molecules under lipopolysaccharide (LPS)-induced inflammatory conditions in MS1 cells. METHODS: MS1 cells (a mouse pancreatic islet endothelial cell line) were grown in Dulbecco's modified Eagle's medium supplemented with 10% fetal bovine serum, 2 mmol/L glutamine and 100 μg/mL penicillin/streptomycin in 5% CO 2 at 37 ℃. After growth to confluency in media, the cells were processed for subsequent studies. The MS1 cells received 0, 0.1, 1 and 10 μg/mL LPS in this experiment. The viability/prolifera-tion of the cells induced by LPS was observed using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide colorimetric assay. Apoptosis and necrosis of the cells under the inflammatory condition described previously were observed using Hoechst 33342-propidium iodide staining. Adenylate cyclase (AC), phospholipase A 2 (PLA 2 ), phospholipase Cβ (PLCβ), protein tyrosine kinase (PTK), G protein-coupled receptor kinases (GRK) and p38-mitogen-activated protein kinase (p38 MAPK) mRNA in the PAFR signaling pathway were measured by real-time polymerase chain reaction. The protein expression level of phosphorylated AC (p-AC), phosphorylated PLA 2 (p-PLA 2 ), phosphorylated PTK (p-PTK), phosphorylated p38 MAPK (p-p38 MAPK), PLCβ and GRK was measured using Western blotting analysis. RESULTS: The activity of MS1 cells incubated with dif- ferent concentrations of LPS for 6 h decreased significantly in the 1 μg/mL LPS group (0.49 ± 0.10 vs 0.67 ± 0.13, P < 0.05) and 10 μg/mL LPS group (0.44 ± 0.10 vs 0.67 ± 0.13, P < 0.001), but not in 0.1 μg/mL group. When the incubation time was extended to 12 h (0.33 ± 0.05, 0.32 ± 0.03 and 0.25 ± 0.03 vs 0.69 ± 0.01) and 24 h (0.31 ± 0.01, 0.29 ± 0.03 and 0.25 ± 0.01 vs 0.63 ± 0.01), MS1 cell activity decreased in all LPS concentration groups compared with the blank control (P < 0.001). BN52021 significantly improved the cell activity when its concentration reached 50 μmol/L compared with the group that received LPS treatment alone, which was consistent with the results obtained from fluorescence staining. The mRNAs levels of AC (4.02 ± 0.14 vs 1.00 ± 0.13), GRK (2.63 ± 0.03 vs 1.00 ± 0.12), p38 MAPK (3.87 ± 0.07 vs 1.00 ± 0.17), PLA 2 (3.31 ± 0.12 vs 1.00 ± 0.12), PLCβ (2.09 ± 0.08 vs 1.00 ± 0.06) and PTK (1.85 ± 0.07 vs 1.00 ± 0.11) were up-regulated after LPS stimulation as compared with the blank control (P < 0.05). The up- regulated mRNAs including AC (2.35 ± 0.13 vs 3.87 ± 0.08), GRK (1.17 ± 0.14 vs 2.65 ± 0.12), p38 MAPK (1.48 ± 0.18 vs 4.30 ± 0.07), PLCβ (1.69 ± 0.10 vs 2.41 ± 0.13) and PLA 2 (1.87 ± 0.11 vs 2.96 ± 0.08)were significantly suppressed by BN52021 except for that of PTK. The level of p-AC (1.11 ± 0.12 vs 0.65 ± 0.08), GRK (0.83 ± 0.07 vs 0.50 ± 0.03), PLCβ (0.83 ± 0.16 vs 0.50 ± 0.10) and p-p38 MAPK (0.74 ± 0.10 vs 0.38 ± 0.05) was up-regulated after LPS stimulation as compared with the blank control (P < 0.05). The up-regulated proteins, including p-AC (0.65 ± 0.15 vs 1.06 ± 0.14), GRK (0.47 ± 0.10 vs 0.80 ± 0.06), PLCβ (0.47 ± 0.04 vs 0.80 ± 0.19) and p-p38 MAPK (0.30 ± 0.10 vs 0.97 ± 0.05), was significantly suppressed by BN52021, but p-PLA 2 and p-PTK protein level were not suppressed. CONCLUSION: BN52021 could effectively inhibit LPS-induced inflammation by down-regulating the mRNA and protein levels of AC, GRK, p38 MAPK, PLA 2 and PLCβ in the PAFR signaling pathway.

Effects of platelet-activating factor on endothelial cell monolayer permeability under hydrostatic perfusion in vitro

A simple and rapid method was established to study vascular permeability by in vitroperfused endothelial cell monolayers cultured on micropore filter membrane.It can be used todetermine filtration coefficient （Kf） to small molecules and osmotic reflection coefficient （σ） toproteins of the endothelial monolayer.Hanks’ balanced salt solution （HBSS） or 5g/L albuminin HBSS was used to perfuse the confluent endothelial monolayer at the hydrostatic pressure of2.45kPa （25cm H2O）.Control Kf values were 10.1±0.75 and 3.6±0.75μl·min-1·cm-2·kPa（-1）（±,n=3） respectively for the perfusion of HBSS and albumin HBSS,suggesting that al-bumin may decrease endothelial monolayer permeability to water and small molecules.After ex-posure of endothelial monolayer to 10-8mol/L platelet-activating factor （PAF） for 30min,Kfvalues increased to 193.1% and 133.3% respectively.Protein clearance rate (μl.min-1·cm-2)and osmotic reflection coefficient of the control endothelial monolayer were 8.0±3.22 and 0.37±0.09 respectively and those of the PAF treated endothelial monolayer 12.2±2.95μl·min-1·cm-2 and 0.18±0.06,revealing increased permeability to albumin.Computer-assisted imageprocessing demonstrated that PAF treatment decreased cell area while increased cell form factorand intercellular space,suggesting that endothelial cells retracted and rounded,which may bean important mechanism of PAF-induced increase of vascular permeability.

In vitro effects of buyang huanwu decoction and its ingredients on inhibiting the specific binding of ~3H-platelet activating factor to its receptor in rabbits

BACKGROUND： Pharmacologic action of traditional Chinese medicine compound is the comprehensive effect of various ingredients, and the interactions of various ingredients are closely correlated with the final effect. In order to reveal the compatibility mechanism of buyang huanwu decoction （BHD）＇s prescription in treating and preventing ischemic cerebrovascular disease, we need to explore the effect and relation of ingredients in prescription except for considering the effect of each ingredient on the whole prescription. OBJECTIVE： To study the effect of BHD and its ingredients in the prescription on the specific binding of 3H-platelet activating factor （PAF） to its receptor （PAFR）in rabbits in vitro, and to analyze the action of each ingredient in the prescription. DESIGN： A decomposed recipe study based on orthogonal test. SETTING： Guangzhou University of Traditional Chinese Medicine. MATERIALS： Five healthy adult New Zealand rabbits of either gender were provided by the Experimental Animal Center of Guangzhou University of Traditional Chinese medicine. The prescription herbal pieces were purchased from Foshan Kangpu Pharmaceuticals Company and Jianmin Pharmaceuticals Company, and were appraised by Professor Yanchen Xu from College of Traditional Chinese Medicine, Guangzhou University of Traditional Chinese Medicine. 3H-PAF was supplied by Amersham Co,Ltd.（Specific activity： 6.475 TBq/mmol;batch number：200402）; PAF standard by Biomol Co., Ltd.（batch number： P1318V）. METHODS： This experiment was carried out in the Laboratory of Nuclear Medicine, Guangzhou University of Traditional Chinese Medicine between September and December 2004. ①The seven influencing factors were selected： such as Shenghuangqi , Dangguiwei, Chishao, Dilong, Taoren, Honghua, Chuanxiong. Each factor was divided into two levels, selected or not selected. The tests were arranged according to L8 （27） orthogonal test table. ②The specific binding of 3H-PAF to its receptors in rabbits was measured by radioligand binding assay. The inhibitory rate of the specific binding was used as an assessing index. The inhibitory action of and on 3H-PAF to PAFR binding was analyzed and compared in vitro. The inhibitory action of each ingredient in the prescription BHD on 3H-PAF to PAFR binding was investigated and compared in vitro by direct analysis and analysis of variance of orthogonal test. MAIN OUTCOME MEASURES： Effect of 8 prescriptions for L8 （27） orthogonal test table on the specific binding inhibition rate of 3H-PAF and PAFR. RESULTS： According to results of variance analysis of orthogonal test, the inhibitory action of each ingredient in the prescription BHD on 3H-PAF to PAFR binding from the highest to the lowest was in turn Honghua, ShenghuangqL Taoren, Dilong, DangguiweL Chuanxiong, Chishao. Honghua, Shenghuangqi, Taoren, Dilong, Danguiwei were major influence factors to 3H-PAF to PAFR in rabbits （F = 187.829,144.446,59.521,5.018,4.265, P 〈 0.05- 0.01）, but Chuanxiong and Chishao had not obviously inhibitory effect. The specific binding inhibition rate of prescriptions （except Shenghuangqi ） was obviously higher than that of one of prescriptions （Shenghuangqi included）. CONCLUSION： The results of orthogonal test show that Honghua, ShenghuangqL Taoren, Dilong, Dangguiwei are major influencing factors to inhibit binding of sH-PAF to PAFR in rabbits, among which, Honghua is the strongest in ingredients of prescription BHD. The results also reveal that Shenghuangqi is able to weaken the inhibitory effect and to prevent the strong inhibitory effect of blood-activating drugs in BHD.

Effect of platelet activating factor on blood spinal cord barrier following cervical cord injury

Effect of platelet activating factor(PAF) on blood spinal cord barrier in cervical cord injury was investigated. Methods: Spinal cord injury at C6 segment was induced with Allen’s ’method in cats. PAF and PAF receptor antagonist BN52021 were administered by arachnoid space and intravenous injection respectively, and their effects on PAF levels, blood spinal cord barrier and cervical cord edema in the injuried zone and adjacent cervical cord tissue following cervical cord injury were investigated. Results: PAF levels, Evens content and water content in the injuried and adjacent cervical cord tissues significantly increased following trauma. PAF levels, Evens content and water content were evidently elevated with PAF by arachnoid space injection. PAF receptor antagonist BN52021 could inhibit the increase in PAF levels and reduce Evens and water content in the cervical cord tissue following trauma. Conclusion: PAF is an important contributing factor causing post-traumatic damage to the blood spinal cord barrier, while PAF receptor antagonist can effectively relieve post-traumatic damage to the blood spinal cord barrier.