Action Of Platelet-activating Factor Research Articles

Effects of Platelet-Activating Factor (PAF) on the Mechanical Activities of Lower Urinary Tract and Genital Smooth Muscles.

Since its first discovery as a bioactive phospholipid inducing potent platelet aggregation, platelet-activating factor (PAF) has been shown to be involved in a wide variety of inflammatory and allergic disease states. Many pharmacological studies in the 1980s and 1990s also showed that PAF induces endothelium-dependent vascular relaxation and contraction of various smooth muscles (SMs), including those in the airway, gastrointestinal organs, and uterus. However, since the late 1990s, there have been few reports on the SM contractions induced by PAF. The lower urinary tract (LUT), particularly the urinary bladder (UB) has attracted recent attention in SM pharmacology research because patients with LUT dysfunctions including overactive bladder are increasing as the population ages. In addition, recent clinical studies have implicated the substantial role of PAF in the inflammatory state in LUT because its production increases with smoking and with cancer. However, the effects of PAF on mechanical activities of LUT SMs including UBSM have not been investigated to date. Recently, we found that PAF very strongly increased mechanical activities of UBSM in guinea pigs and mice, and partly elucidated the possible mechanisms underlying these actions of PAF. In this review, we describe the effects of PAF on LUT SMs by introducing our recent findings obtained in isolated UBSMs and discuss the physiological and pathophysiological significance. We also introduce our data showing the effects of PAF on the SM mechanical activities of genital tissues (prostate and vas deferens).

Investigations into the role of platelet-activating factor in the peri-conception period of the mare.

In many mammals, the lipid platelet-activating factor (PAF) has important functions in female reproduction and fertility. This study shows that PAF is present in the reproductive tissues of mares and is involved in processes related to ovulation and early pregnancy. Platelet-activating factor (PAF) has been implicated in a number of reproductive processes ranging from ovulation to embryo motility but has not been widely explored in the mare. To identify the presence and examine the role of PAF in the equine periconception processes, targeted mass spectrometry coupled with chromatographic separation was performed on equine follicular fluid (FF), and PAF was quantitatively detected. Subsequently, untargeted high-resolution mass spectrometry-based lipidomic analysis was carried out to quantify PAF in different-sized pre-ovulatory follicles, whereby different molecular species of PAF, PAF (14:0) and PAF (16:1), were both seen to be increasing with follicle diameter. These findings suggest that PAF within FF is increasing as preovulatory follicles approach ovulation. Additionally, immunofluorescence staining identified the PAF receptor in the luminal pericellular, apical, and basal aspect of equine oviductal epithelial cells. Lastly, an equine oviductal epithelial organoid model was generated and showed that the addition of PAF significantly increased the ciliary beat frequency (CBF) (Hz), an action consistent with a role for PAF in embryo migration. It is proposed that the local action of PAF on the ciliated cells of the oviduct propels both the oocyte and the conceptus towards the uterus. In the mare, it appears that PAF is a contributor during the periconception period, potentially being a mediator in the mechanisms of ovulation and in the dialogue of very early pregnancy.

Enhanced Fc Receptor Expression In Sea Urchin Spermatozoa By Platelet-Activating Factor

Platelet-activating factor (PAF) is a signaling phospholipid that has a variety of reproductive roles, e.g. sperm capacitation and the acrosome reaction (an exocytotic process). PAF’s mechanism action involves G-protein receptor activation induction of intracellular calcium, which enhances sperm motility. In nonreproductive cells, the Fc receptor (FcR) functions in ligand-triggered transmission signals across the membrane which alters secretion, exocytosis, and increased intracellular calcium. This study looked at the impact of PAF on FcR expression in sea urchin spermatozoa. Sea urchin sperm were exposed to exogenous PAF (10-7M; 15 minutes) and evaluated for FcR activity via flow cytometry. A significant (P=0.01) difference (64.30%) in FcR wave activity between the PAF (mean 3.286) and control (2.0) groups was observed. Within waves, there were more (83.31%) high points (crests) in the PAF (mean 1.571) group than the control (mean 0.857) group. Similarly, there were more (49.96%) low (troughs) points in the PAF (mean 1.714) group than the control (mean 1.143) group. This is the first report to demonstrate a relative positive change in spermatozoa FcR expression when exposed to PAF. The FcR functions in ligand-triggered transmission of PAF via a G-protein coupled receptor mediated pathway leading to physiological alterations. Provided the known mechanism of action of PAF on spermatozoa physiology, the data suggests that the interaction of PAF and FcR play a pivotal role in sperm activity and fertilization potential.

Protective Effect of Olive Oil Microconstituents in Atherosclerosis: Emphasis on PAF Implicated Atherosclerosis Theory.

Atherosclerosis is a progressive vascular multifactorial process. The mechanisms underlining the initiating event of atheromatous plaque formation are inflammation and oxidation. Among the modifiable risk factors for cardiovascular diseases, diet and especially the Mediterranean diet (MedDiet), has been widely recognized as one of the healthiest dietary patterns. Olive oil (OO), the main source of the fatty components of the MedDiet is superior to the other "Mono-unsaturated fatty acids containing oils" due to the existence of specific microconstituents. In this review, the effects of OO microconstituents in atherosclerosis, based on data from in vitro and in vivo studies with special attention on their inhibitory activity against PAF (Platelet-Activating Factor) actions, are presented and critically discussed. In conclusion, we propose that the anti-atherogenic effect of OO is attributed to the synergistic action of its microconstituents, mainly polar lipids that act as PAF inhibitors, specific polyphenols and α-tocopherol that also exert anti-PAF activity. This beneficial effect, also mediated through anti-PAF action, can occur from microconstituents extracted from olive pomace, a toxic by-product of the OO production process that constitutes a significant ecological problem. Daily intake of moderate amounts of OO consumed in the context of a balanced diet is significant for healthy adults.

Activities of platelet-activating factor (PAF) enzymes after daily consumption for two months of a yogurt enriched with natural origin PAF inhibitors

Background and Aims: Platelet-activating factor (PAF), a pro-inflammatory lipid mediator, plays a crucial role in the formation of the atherosclerotic plaque. Therefore, the inhibition of endothelium inflammation by nutraceuticals, such as PAF inhibitors, is a promising alternative for preventing cardiovascular diseases. The aim of the present study is to evaluate the impact of a new functional yogurt enriched with natural origin PAF inhibitors from olive oil by-products on PAF metabolism.

Consumption of Enriched Yogurt with PAF Inhibitors from Olive Pomace Affects the Major Enzymes of PAF Metabolism: A Randomized, Double Blind, Three Arm Trial

Platelet-activating factor (PAF), a proinflammatory lipid mediator, plays a crucial role in the formation of the atherosclerotic plaque. Therefore, the inhibition of endothelium inflammation by nutraceuticals, such as PAF inhibitors, is a promising alternative for preventing cardiovascular diseases. The aim of the present study was to evaluate the impact of a new functional yogurt enriched with PAF inhibitors of natural origin from olive oil by-products on PAF metabolism. Ninety-two apparently healthy, but mainly overweight volunteers (35–65 years) were randomly allocated into three groups by block-randomization. The activities of PAF’s biosynthetic and catabolic enzymes were measured, specifically two isoforms of acetyl-CoA:lyso-PAF acetyltransferase (LPCATs), cytidine 5′-diphospho-choline:1-alkyl-2-acetyl-sn-glycerol cholinephosphotransferase (PAF-CPT) and two isoforms of platelet activating factor acetylhydrolase in leucocytes (PAF-AH) and plasma (lipoprotein associated phospholipase-A2, LpPLA2). The intake of the enriched yogurt resulted in reduced PAF-CPT and LpPLA2 activities. No difference was observed in the activities of the two isoforms of lyso PAF-AT. In conclusion, intake of yogurt enriched in PAF inhibitors could favorably modulate PAF biosynthetic and catabolic pathways.

Micronutrients, Phytochemicals and Mediterranean Diet: A Potential Protective Role against COVID-19 through Modulation of PAF Actions and Metabolism.

The new coronavirus disease 2019 (COVID-19) pandemic is an emerging situation with high rates of morbidity and mortality, in the pathophysiology of which inflammation and thrombosis are implicated. The disease is directly connected to the nutritional status of patients and a well-balanced diet is recommended by official sources. Recently, the role of platelet activating factor (PAF) was suggested in the pathogenesis of COVID-19. In the present review several micronutrients (vitamin A, vitamin C, vitamin E, vitamin D, selenium, omega-3 fatty acids, and minerals), phytochemicals and Mediterranean diet compounds with potential anti-COVID activity are presented. We further underline that the well-known anti-inflammatory and anti-thrombotic actions of the investigated nutrients and/or holistic dietary schemes, such as the Mediterranean diet, are also mediated through PAF. In conclusion, there is no single food to prevent coronavirus Although the relationship between PAF and COVID-19 is not robust, a healthy diet containing PAF inhibitors may target both inflammation and thrombosis and prevent the deleterious effects of COVID-19. The next step is the experimental confirmation or not of the PAF-COVID-19 hypothesis.

Substituted pyridine-quinoline ligands as building blocks for neutral rhodium(III) complexes. Synthesis, structural characterization studies and anti-platelet activity towards the Platelet-Activating Factor (PAF)

The Friedländer condensation reaction was employed to synthesize the new bidentate ligands namely 6-bromo-4-phenyl-2-pyridin-2-yl-quinoline (1) and 4-(4-phenyl-2-(pyridin-2-yl)quinolin-6-yl)phenol (2). These compounds were fully characterized including the X-ray structures of 1 and the protonated form of 2, i.e. 2·HCl·H2O. We also report the synthesis and spectroscopic characterization of two rhodium(III) complexes of the general formula [Rh(1)Cl3(CH3OH)] (3) and [Rh(2)Cl3(CH3OH)] (4). The molecular structures of 3·2CH3OH and 4 were determined by single-crystal X-ray diffraction studies, revealing that these complexes adopt the mer-configuration. The solution stability of 3, 4 was studied by a combination of UV–Vis and 1H NMR spectroscopic techniques. All compounds were biologically evaluated for their anti- platelet activity using their potency to inhibit the action of PAF (Platelet-Activating Factor), which is an approach of continuous interest in the field. Complexes 3 and 4 were found to be potent PAF inhibitors with IC50 values in the micromolar range (1.0 μM and 3.9 μM respectively). Since PAF is the most potent inflammatory lipid mediator, the PAF-inhibitors and consequently the title compounds may be considered as potent examples in the search for novel anti-inflammatory drugs.

Consumption of plant extract supplement reduces platelet activating factor-induced platelet aggregation and increases platelet activating factor catabolism: a randomised, double-blind and placebo-controlled trial.

Platelet-activating factor (PAF) is a potent mediator of inflammation that plays a crucial role in atherosclerosis. The purpose of this study was to evaluate the effect of a dietary supplement containing mainly plant extracts on PAF actions and metabolism in healthy volunteers. A double-blind, placebo-controlled, 8 weeks' duration study was performed. Healthy volunteers were randomly allocated into the supplement or the placebo group and fifty-eight of them completed the study. The supplement contained plant extracts (Aloe gel, grape juice, Polygonum cuspidatum) and vitamins. The activities of PAF metabolic enzymes: the two isoforms of acetyl-CoA:lyso-PAF acetyltransferase, cytidine 5'-diphospho-choline:1-alkyl-2-acetyl-sn-glycerol cholinephosphotransferase (PAF-cholinephosphotransferase) and platelet-activating factor-acetylhydrolase (PAF-AH) in leucocytes and lipoprotein associated phospholipase-A2 in plasma were measured along with several markers of endothelial function. Platelet aggregation against PAF, ADP and thrombin receptor activating peptide was measured in human platelet-rich plasma by light transmission aggregometry. No difference was observed on soluble vascular cell adhesion molecule-1, sP-selectin and IL-6 levels at the beginning or during the study period between the two groups. Concerning PAF metabolism enzymes' activity, no difference was observed at baseline between the groups. PAF-AH activity was only increased in the supplement group at 4 and 8 weeks compared with baseline levels. In addition, supplement consumption led to lower platelet sensitivity against PAF and ADP compared with baseline levels. However, a trial effect was only observed when platelets were stimulated by PAF. In conclusion, supplementation with plant extracts and vitamins ameliorates platelet aggregation primarily against PAF and secondarily against ADP and affects PAF catabolism by enhancing PAF-acetylhydrolase activity in healthy subjects.

Mesenchymal Stromal Cells Modulate PAF-stimulated Equine Alveolar Macrophages

Abstract Platelet-activating factor (PAF) is a potent proinflammatory mediator that is produced in increased amounts in the lungs of asthmatic humans and horses. The present pilot study, shows that mesenchymal stromal cells can modulate alveolar macrophage function in asthma, interfering in the activity of PAF, being another potential pathway for mesenchymal stromal cells benefits in asthma.

The Potential Role of Dietary Platelet-Activating Factor Inhibitors in Cancer Prevention and Treatment.

Cancer is the second leading cause of mortality worldwide. The role of unresolved inflammation in cancer progression and metastasis is well established. Platelet-activating factor (PAF) is a key proinflammatory mediator in the initiation and progression of cancer. Evidence suggests that PAF is integral to suppression of the immune system and promotion of metastasis and tumor growth by altering local angiogenic and cytokine networks. Interactions between PAF and its receptor may have a role in various digestive, skin, and hormone-dependent cancers. Diet plays a critical role in the prevention of cancer and its treatment. Research indicates that the Mediterranean diet may reduce the incidence of several cancers in which dietary PAF inhibitors have a role. Dietary PAF inhibitors such as polar lipids have demonstrated inhibitory effects against the physiological actions of PAF in cancer and other chronic inflammatory conditions in vitro and in vivo. In addition, experimental models of radiotherapy and chemotherapy demonstrate that inhibition of PAF as adjuvant therapy may lead to more favorable outcomes. Although promising, there is limited evidence on the potential benefits of dietary PAF inhibitors on cancer prevention or treatment. Therefore, further extensive research is required to assess the effects of various dietary factors and PAF inhibitors and to elucidate the mechanisms in prevention of cancer progression and metastasis at a molecular level.

Inflammation, not Cholesterol, Is a Cause of Chronic Disease.

Since the Seven Countries Study, dietary cholesterol and the levels of serum cholesterol in relation to the development of chronic diseases have been somewhat demonised. However, the principles of the Mediterranean diet and relevant data linked to the examples of people living in the five blue zones demonstrate that the key to longevity and the prevention of chronic disease development is not the reduction of dietary or serum cholesterol but the control of systemic inflammation. In this review, we present all the relevant data that supports the view that it is inflammation induced by several factors, such as platelet-activating factor (PAF), that leads to the onset of cardiovascular diseases (CVD) rather than serum cholesterol. The key to reducing the incidence of CVD is to control the activities of PAF and other inflammatory mediators via diet, exercise, and healthy lifestyle choices. The relevant studies and data supporting these views are discussed in this review.

Urinary Platelet‐Activating Factor as an Indicator of Interstitial Cystitis/Bladder Pain Syndrome

Interstitial cystitis/bladder pain syndrome (IC/BPS) is a chronic inflammatory bladder disease with multiple etiological contributors and risk factors associated with its development, including cigarette smoking. In a recently published manuscript, we have shown that smoking is associated with bladder wall inflammation and accumulation of platelet activating factor (PAF), a potent inflammatory mediator that facilitates transendothelial inflammatory cell migration and reduction in tight junction protein expression, which could contribute to urothelial cell dysfunction. PAF accumulation in response to cigarette smoking is primarily the result of the inhibition of PAF acetylhydrolase (PAF‐AH, the enzyme responsible for PAF hydrolysis and inactivation). The present study was designed to determine whether urine content of PAF or PAF‐AH activity can be used as an indicator of IC/BPS. For stability studies, voided urine specimens were collected from patients with and without a diagnosis of IC/BPS. Samples were stored at room temperature and frozen in liquid nitrogen at intervals up to 60 mins following voiding. PAF content and PAF‐AH activity were measured and normalized to creatinine. Measurement of PAF and PAF‐AH was consistent at all time intervals up to 60 mins, demonstrating stability following voiding. Addition of PAF internal standard to urine samples prior to analysis indicated a recovery of >96% PAF. PAF content in the urine of IC/BPS patients (1.16 ± 0.16 PAF:creatinine ratio, n=6, p<0.05) was significantly greater than that for non‐IC/BPS patients (0.37 ± 0.18 PAF:creatinine ratio, n=5). PAF content was also greater in IC/BPS patients who smoke (1.19 + 0.36 PAF:creatinine ratio, n=4, p<0.05) when compared to non‐IC/BPS patients. PAF‐AH activity was decreased in the urine of IC/BPS patients who were smokers (48.3 ± 2.4 PAF‐AH: creatinine ratio, n=4, p<0.05) or non‐smokers (40.0 ± 7.0 PAF‐AH: creatinine ratio, n=6, p<0.05) when compared to non‐smokers with no IC/BPS (64.6 ± 2.2 PAF‐AH:creatinine ratio, n=5). Our data demonstrate that urine content of PAF and/or PAF‐AH is stable at up to 60 mins storage at room temperature following voiding. Urinary PAF is increased in IC/BPS patients, and is likely the result of PAF‐AH inhibition. Future studies are required to determine the effect of cigarette smoking on the incidence and severity of IC/BPS.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Ιn Vivo Effects of Tenofovir-DF/Emtricitabine and Abacavir/Lamivudine with Atazanavir-R on Platelet Activating Factor Metabolism in HIV Naive Patients

Antiretroviral therapy (ΑRT) has successfully decreased AIDS morbidity and mortality and increased the lifespan of HIV patients to several decades. However, numerous factors contribute with unknown mechanisms to chronic immune activation and inflammation leading to severe “non-AIDS morbidities’’. Platelet Activating Factor (PAF) is a potent lipid inflammatory mediator with important role in the ‘’non-AIDS morbidities’’. The purpose of this study was to investigate whether tenofovir-DF/emtricitabine and abacavir/lamivudine with atazanavir boosted ritonavir (ART_A and ART_B, respectively) affect in vitro PAF activity and in vivo PAF levels and metabolism. In this intent, the two ART regimens were examined in vitro against platelet aggregation induced by PAF. In addition, PAF levels and PAF metabolic enzymes were determined in HIV-1 infected volunteers before and after the initiation of antiretroviral therapy for a 12-month period. The in vitro results showed that ritonavir was the most potent inhibitor against PAF induced platelet aggregation while abacavir presented the less potent action. The in vivo results showed that tenofovir-DF/emtricitabine with atazanavir-r seems not to affect PAF levels and metabolism while abacavir/lamivudine with atazanavir-r increased bound and total PAF blood levels, PAF biosynthesis in platelets and also decreased Lp-PLA2 activity. In addition, ART_B revealed higher lyso-PAF-AT specific activity at 3rd, 6th and 9th month (p3=0.04, p6=0.04 and p9=0.03) compared to ART_A. In conclusion, there is a direct relation between in vitro and in vivo effect of antiretrovirals on PAF and abacavircontaining regimen activates PAF biosynthesis leading to elevated PAF levels.

In Vitro Effects of Anti-Glaucomatous Eye Drops on Platelet-Activating Factor and its Metabolism

Purpose: The purpose of this study is to determine the effect of various commonly used antiglaucoma eye drops on inflammatory mediators such as the platelet activating factor (PAF). Methods: Various intraocular pressure (IOP) lowering drops were tested to examine their inhibitory effect on PAF. Multiple eye drops were tested in washed rabbit platelets (WRPs) in order to determine the interaction between these eye drops and the inhibition of PAF in the PAF-induced platelet aggregation model. In addition, we examined the eyedrops’ effect on PAF-metabolism, through in vitro analysis on PAF basic metabolic enzymes (PAF-CPT, lyso PAF-AT, and PAF-AH). Results: Latanoprost (Xalatan) was found to be the most potent in inhibiting PAF, suggesting that it is the most effective in decreasing IOP amongst the eye drops tested. Conversely, dorzolamide hydrochloride-timolol (Cosopt) exhibited the least anti-PAF action. Conclusions: This is the first study examine the relationship between PAF activity and glaucoma medication. Potency in PAF inhibition may be related to drop efficacy.

Pneumonia and venous thromboembolism: Is the evidence catching up with the guidelines?

See article, page 799

Interaction of the Humoral Agonist During the Platelets Activation in Patients with Chronic Cerebral Ischemia

The aim of the study was to determine the effect of the standard drug therapy of 95 patients with chronic cerebral ischemia (CCI) on the functional status of platelets as possible participants of microcirculation of the brain. Platelets were isolated from peripheral blood by centrifugation and examined at 24 hours after initiation of standard medical therapy including aspirin (100 mg). The cells were stimulated in vitro using adenosine diphosphate (ADP), epinephrine, platelet activating factor (PAF) and serotonin in an effective concentration (EC50) inducing in healthy individuals platelet aggregation in the range of 50 ± 5%. A study of platelet aggregation was carried out on aggregometer Chrono-Log (USA). Research included 95 patients with CCI 1-2 Stage--82 patients taking antiplatelet and antihypertensive drugs before hospitalization (main group), 13--did not receive these drugs during 7 days prior to hospitalization (comparison group). After start conservative treatment, only ADP induced platelet aggregation, which was similar (p > 0.05) with values in healthy individuals. The pharmacological inhibition of the functional activity of platelets other investigated agonists reproduced hyporesponsiveness of platelets. Against this background, in 34 (41.5%) patients at 24 hours after initiation of therapy occurred potentiation effects of PAF and epinephrine in the test in vitro; whereas the summation of the effects of serotonin and epinephrine on platelets was detected in 12 (14.6%) patients. The basis of this phenomenon may be strengthening effect of ADP secreted from dense-granules, additional stimulation by Gi-protein signaling system by epinephrine and Gq-protein by the action of PAF and serotonin. Response to the combined action of platelet agonists may be predictor of the risk of thrombogenesis at CCI.

Mouse anaphylactic shock is caused by reduced cardiac output, but not by systemic vasodilatation or pulmonary vasoconstriction, via PAF and histamine

AimsSystemic anaphylaxis is life-threatening, and its pathophysiology is not fully clarified. Mice are frequently used for experimental study on anaphylaxis. However, the hemodynamic features and mechanisms of mouse anaphylactic hypotension remain unknown. Therefore, we determined mechanisms of systemic and pulmonary vascular response to anaphylactic hypotension in anesthetized BALB/c mice by using receptor antagonists of chemical mediators. Main methodsAnaphylaxis was actively induced by an intravenous injection of the ovalbumin antigen into open-chest artificially ventilated sensitized mice. Mean arterial pressure (MAP), pulmonary arterial pressure (PAP), left atrial pressure, central venous pressure, and aortic blood flow (ABF) were continuously measured. Key findingsIn sensitized control mice, MAP and ABF showed initial, transient increases, followed by progressive decreases after the antigen injection. Total peripheral resistance (TPR) did not decrease, while PAP initially and transiently increased to 18.5±0.5mmHg and pulmonary vascular resistance (PVR) also significantly increased. The antigen-induced decreases in MAP and ABF were attenuated by pretreatment with either a platelet-activating factor (PAF) receptor antagonist, CV6209, or a histamine H1 receptor antagonist, diphenhydramine, and were abolished by their combination. Diphenhydramine augmented the initial increases in PAP and PVR, but did not affect the decrease of the corresponding MAP fall. The antagonists of either leukotriene C4 or serotonin, alone or in combination with CV6209, exerted no significant effects. SignificanceMouse anaphylactic hypotension is caused by a decrease in cardiac output but not vasodilatation, via actions of PAF and histamine. The slight increase in PAP is not involved in mouse anaphylactic hypotension.

Inhibitory effects of the platelet-activating factor receptor antagonists, CV-3988 and Ginkgolide B, on alkali burn-induced corneal neovascularization

Purpose: Platelet-activating factor (PAF) has been found in various ocular tissues; the activity of PAF depends on the binding to its specific receptor, PAF-receptor. We investigated the therapeutic effects of PAF-receptor antagonists (CV-3988 and Ginkgolide B) on alkali burn-induced corneal neovascularization (CNV).Methods: CNV was induced by applying a 0.2 N sodium hydroxide (3 µl, NaOH) solution directly on mice corneas. CV-3988 (1 mM/10 µl) and Ginkgolide B (1 mM/10 µl) were administered topically on the corneas three times daily for three consecutive days. CNV was evaluated under a slit-lamp microscope. Corneas were processed for histological, immunohistochemical and reverse transcription polymerase chain reaction analysis. Human umbilical vein endothelial cells were used for the migration and tube formation assay.Results: Application of CV-3988 and Ginkgolide B inhibited CNV caused by alkali burn. CV-3988 and Ginkgolide B attenuated the expression of PAF-receptor mRNA. Alkali injury induced a massively increased intraocular mRNA expression of an angiogenic factor in cornea tissues, whereas these increments were attenuated by the application of CV-3988 and Ginkgolide B.Conclusions: CV-3988 and Ginkgolide B reversed opacity and neovascularization in alkali burn-induced corneas. Our findings suggest that CV-3988 and Ginkgolide B may be therapeutically useful in the treatment of CNV and inflammation.

Platelet-activating Factor Contributes to Bacillus anthracis Lethal Toxin-associated Damage

The lethal toxin (LeTx) of Bacillus anthracis plays a central role in the pathogenesis of anthrax-associated shock. Platelet-activating factor (PAF) is a potent lipid mediator that has been implicated in endotoxin-associated shock. In this study, we examined the contribution of PAF to the manifestations of lethal toxin challenge in WT mice. LeTx challenge resulted in transient increase in serum PAF levels and a concurrent decrease in PAF acetylhydrolase activity. Inhibition of PAF activity using PAF antagonists or toxin challenge of PAF receptor negative mice reversed or ameliorated many of the pathologic features of LeTx-induced damage, including changes in vascular permeability, hepatic necrosis, and cellular apoptosis. In contrast, PAF inhibition had minimal effects on cytokine levels. Findings from these studies support the continued study of PAF antagonists as potential adjunctive agents in the treatment of anthrax-associated shock.