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.

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.

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.

Effects of Buyang Huanwu decoction and Astragalus mongholicus on platelet activating factor receptor activity in rabbits in vitro

BACKGROUND: The pharmacological action of traditional Chinese medicine compound is the comprehensive effect of the various ingredients, and the interactions of various ingredients are closely correlated with the final effect. In order to reveal the compatibility mechanism of BHD's prescription in treating and preventing ischemic cerebrovascular disease, we needed explore the effect and relation of ingredients in the prescription. OBJECTIVE: To observe the effect of Buyang Huanwu decoction (BHD) and Astragalus mongholicus on the activity of platelet activating factor receptor (PAFR) in the platelet of rabbits in vitro, and investigate the mechanism of Astragalus mongholicus. DESIGN: A decomposed recipes study. SETTING: Guangzhou University of Traditional Chinese Medicine. MATERIALS: Five New Zealand rabbits, weighing 2-3 kg, both sexes, were used. BHD was composed of Sheng Huang Qi 120 g, Dang Gui Wei 6 g, Chi Shao 4.5 g, Chuan Xiong 3 g, Di Long 3 g, Tao Ren 3 g, Hong Hua 3 g. The prescription for activating blood circulation consisted of Dang Gui Wei 6 g, Chi Shao 4.5 g, Chuan Xiong 3 g, Di Long 3 g, Tao Ren 3 g and Hong Hua 3 g. The prescription for invigorating qi consisted of 120 g Sheng Huang Qi. The prepared herbal pieces were purchased from the traditional Chinese medicine Dispensary of Foshan Second People's Hospital, and appraised by Professor Xu from Science of Chinese Materia Medica College, 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: The experiments were carried out in the Laboratory of Nuclear Medicine, Guangzhou University of Traditional Chinese Medicine from September to December 2004. ① Injections of BHD, prescriptions for activating blood circulation and invigorating qi were prepared by the decoction and alcohol sedimentation technique. Rabbit common carotid artery blood (40 mL) was drawn via intubation to prepare platelet suspension of (0.8-1.0)×1010 L-1. ② Determination of 3H-PAF and washed PAFR binding: The general combination tube (T) contained washed platelet-rich plasma (WPRP) 380 μL + 3H-PAF (0.35 nmol/L)10 μL+distilled water 5 μL; The nonspecific binding tube (P) contained WPRP 380 μL+3H-PAF(0.35 nmol/L)10 μL+cold PAF (1 μmol/L) 5 μL; The sample tube (Y) contained WPRP 380 μL+3H-PAF(0.35 nmol/L)10 μL+experimental medicine (injection of BHD, prescriptions for activating blood circulation or invigorating qi) 5 μL. The test was conducted for three times for each sample in the same way as mentioned above. The samples were shaken on the oscillator for 30 s, then bathed at 25 ℃ for 40 minutes, and the reaction was terminated with cold Tris buffer containing 0.1% BSA, multichannel cell detachment separator was used for vacuum suction to filter the separated free 3H-PAF, and the filter paper was washed with cold Tris buffer for four times, then dried in the baking oven (80 ℃) for 1 hour, and placed in xylol liquid scintillator, and the radioactivity was determined automatically by the liquid scintillation detector. The mean of the three parallel tubes was calculated. The specific binging inhibition rate was calculated: SBIR=[(T-Y)/(T-P)]×100%]. ③ Univariate analysis of variance was conducted. And for comparison of each paired groups, the q test was adopted. MAIN OUTCOME MEASURES: Effect of BHD whole prescription, prescriptions for activating blood circulation and invigorating qi on the specific binding inhibition rate of 3H-PAF and PAFR. RESULTS: BHD, prescriptions for activating blood circulation and invigorating qi were all able to inhibit the specific binding of 3H-PAF to PAFR, the specific blinding inhibition rates were (45.90±7.50)%, (97.90±1.84)% and (26.75±2.48)%, respectively, and there were significant differences between every two groups (P < 0.01). CONCLUSION: Single Astragalus mongholicus (120 g) can inhibit the specific blinding of PAFR in the platelet of the rabbit with 3H-PAF, but the combination of Astragalus mongholicus with the drugs for activating blood circulation in BHD can significantly decrease the inhibiting action of the latter on PAFR activity of the platelet, reflecting the combined mechanism of 'removing blood stasis without injuring the vital qi' in BHD.

Effect of Volatile Oil of Amomum on Expressions of Platelet Activating Factor and Mastocarcinoma-related Peptide in the Gastric Membrane of Chronic Gastritis Patients with Helicobacter-pylori Infection

Objective： To observe the effect of volatile oil of amomum （VOA） on the expressions of mastocarcinoma-related peptide （PS2） and platelet activating factor （PAF） in helicobacter pylori- associated gastritis （HPG） and to analyze its potential mechanism. Methods： Eighty patients with HPG were randomly assigned to two groups, 42 patients in the treated group treated with 0.5 mL VOA, thrice per day; and the 38 patients in the control group receiving Western tertiary medicinal treatment. Gastroscopic picture and helicobacter pylori （HP） infection （by quick urease and Warthin- Starry stain） of the gastro-membrane, expressions of PS2 and PAF （by immunohistochemical assay and Western blotting） as well as the contents of aminohexose and phospholipid （by Neuhaus method） in the gastric membrane of all patients were detected before treatment and 4 weeks after treatment. The clinical efficacy in the two groups was compared. Results： The total effective rate in the treated group was 88.1%, which was significantly higher than that in the control group （78.9%, P〈0.05）. After treatment, in the treated group, gastric membranous contents of aminohexose and phospholipid was increased, expression of PS2 elevated but that of PAF lowered, all showing significant difference as compared with those in the control group （P〈0.01）. In the control group, the expressions of PS2 and PAF changed insignificantly. The radical eliminating rate of HP in the treated group and the control group was insignificantly different between them （76.1% vs. 65.8%, P 〉 0.05）. Conclusion： The mechanism of VOA for anti-gastritis might be related with its action in increasing the expression of PS2 and decreasing the expression of PAF, and thus regulating the hydrophobicity of the gastric membrane.

Role of platelet activating factor in pathogenesis of acute respiratory distress syndrome

The acute respiratory distress syndrome （ARDS） is defined by noncardiogenic pulmonary edema and acute respiratory failure in the seriously ill patients. It represents the serious pulmonary response to a broad range of severe injuries occurring either directly to the lung or as the consequence of injury or inflammation at other sites in the body. With the great advance in the treatment of serious diseases such as severe trauma, shock and sepsis, many patients do not die of original diseases but develop ARDS, which makes the incidence of ARDS increase. Results from a recent thorough epidemiological study conducted in Seattle suggested ARDS incidence figure of 59 cases per 100000 inhabitants/year.

Influence of Buyang Huanwu Decoction (补阳还五汤) on Activity of Blood Platelet Activating Factor Receptor in Rabbit

Objective: To observe the influence of Buyang Huanwu Decoction (BYHWD) on the activity of blood platelet activating factor receptor (PAFR). Methods: BYHWD was administered to rabbits in vitro or in vivo and its effect on PAFR was observed by radioligand receptor binding method. Results: BYHWD tended to increase the specific binding amount of washed platelet PAFR with radioligand in vivo, which was similar to that of Ginkgo leaf extract. And in vitro, it showed an inhibition on the specific binding of washed platelet PAFR. Conclusion: BYHWD has certain effect on PAFR amount in vivo and PAFR activity in vitro.

Pharmacological action and mechanisms of ginkgolide B

Objective To review the recent research progress in pharmacological actions and mechanisms of ginkgolide B. Data sources Information included in this article was identified by searching of PUBMED （1987-2006） online resources using the key terms ＂ginkgolide B＂, ＂platelet activating factor＂, and ＂pharmacological＂. Study selection Mainly original milestone articles and critical reviews written by major pioneer investigators of the field were selected. Results The key issues related to the pharmacological actions and mechanisms of ginkgolide B were summarized. The ginkgolide B possesses a number of beneficial effects such as anti-inflammatory, anti-allergic, antioxidant, and neuroprotective effects. Meantime, their mechaniams were discussed. Conclusions The Ginkgolide B is the most potent antagonist of platelet activating factor （PAF） and exhibits therapeutic action in a variety of diseases mainly by the PAF receptor.

EXPERIMENTAL WORK and RESEARCH Effect of Reduqing(热毒清) on TNF-α,IL-1,IL-6,IL-8 and PAF Levels in Endotoxin-Induced DIC Model of Rabbits

Objective: To study the mechanism of anti-endotoxemic effect of Reduqing Injection (RDQ)and to explore the essence of traditional Chinese 'heat-clearing and detoxifying therapy'. Methods: A disseminated intravascular coagulation (DIC) model was made in rabbits by intravenous injection with E. colt endotoxin. Increased plasma levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-8 (IL-8) and platelet activating factor (PAF), as well as the ex-vivo LPS-induced interleukin-1 (IL-1 ) production in peripheral blood monocytes were observed in model (M) group. Results: Same parameters were significantly lower in RDQ and dexamethasone (DXM) groups than those in the M group (P < 0. 01, P < 0. 05). Histopathological examination showed severe damage of the liver, lungs and kidneys in the rabbits of M group, in contrast, only mild affects were seen in the RDQ and DXM groups. Conclusions: RDQ exhibits protective effect on rabbits against endotoxin-induced DIC. The suppression of cytokines and inflammatory mediator PAF by RDQ may play a central role in the inhibition of endotoxin-induced DIC cascade.

Clinical Study on Treatment of Liver Fibrosis of Chronic Hepatitis B Patients with Ginkgo Leaf

Objective To study the anti-liver fibrosis effect of Ginkgo leaf in patients with chronic hepatitis B.Methods: Eighty-six patients with chronic hepatitis B were randomly divided into two groups with similar general condition. The 42 patients in the treated group were treated with Ginkgo leaf tablet (GLT), and the 44 patients in the control group were treated with Yiganling tablet. The treatment was conducted for 3 successive months in both groups. Changes in the histo-pathology of liver, serum levels of platelet activating factor (PAF), hyaluronic acid (HA), collagen type IV (C-IV), laminin (LN) and pro-collagen peptide type III (PC III) were observed before and after treatment. Results The markedly effective rate and the total effective rate in the treated group were 45.1% and 76.2% respectively, while in the control group the corresponding rates were 18. 2% and 43. 2%. Comparison between the two groups showed significant differenceP<0.01). Serum levels of PAF, HA, C-IV, LN and PC III were lowered significantly in the treated group after treatment. Compared with the corresponding parameters in the control group after treatment, the differences were all significant (P<0.01 orP<0.05). The pathological examination of liver showed improvement in both groups, the inflammation grade lowered in 10 patients (55. 6%) of the treated group and in 5 patients (35. 7%) of the control group, insignificant difference was shown between them. But in comparing the fibrosis staging lowering patients between the two groups, 12 patients (66. 7%) vs 3 patients (21.4%), the difference was significantP<0.05). Moreover, there were 4 patients in the control group with their fibrosis aggravated, while in the treated group, none was aggravatedP<0.05). Conclusion Ginkgo leaf tablet has some liver protective and anti-liver fibrosis benefits.