Cellular localization of platelet-activating factor (PAF) receptor in the rat brain was determined by (1) in situ hybridization, (2) Northern blot analysis in primary cell cultures of neurons, microglia, astrocytes, and fibroblasts, and (3) Ca2+ imaging in hippocampal culture. In situ hybridization revealed that the PAF receptor mRNA is expressed intensely in microglia and moderately in neurons...

The phospholipid mediator platelet-activating factor (PAF), and its non-hydrolyzable analog methylcarbamyl-PAF (mc-PAF) increase prostaglandin E(2) (PGE(2)) release from astrocyte-enriched cortical cell cultures. Cyclooxygenase (COX) enzymes--of which there are two known isoforms--convert arachidonic acid to prostaglandin (PG) H(2) (PGH(2)), which is further metabolized to various PGs, includin...

1. U937 cells are a continuous line of human cells of committed monocytic origin which serve as a useful model for studying human monocytic function. The present study investigated the effect of platelet-activating factor (Paf) on intracellular free calcium ion concentration ([Ca2+]i) in U937 cells using the calcium fluorescent probe fura-2. 2. The naturally-occurring stereoisomer (R)-Paf (0.01...

BACKGROUND AND PURPOSE Platelet-activating factor (PAF) has been demonstrated to have a mediator function in shock, with some of its deleterious effects being attributed to its influence on microcirculation. Systemic PAF concentrations as found in shock could also compromise the cerebral microcirculation. Our purpose in the present study was to examine the influence of systemically applied PAF ...

We examined whether platelet-activating factor (PAF) and its receptor mediate lipopolysaccharide (LPS)-induced fever and hypothermia in rats. Two highly potent, structurally distinct antagonists of the PAF receptor, CV6209 and WEB2086, were used. At a neutral ambient temperature (Ta) of 30ºC, administration of LPS at a low (10 μg/kg, i.v.) or high (1,000 μg/kg, i.v.) dose resulted in fever. The...

BACKGROUND To examine the association between potentially modifiable risk factors with cardiovascular disease (CVD) and all-cause mortality and to quantify their population attributable fractions (PAFs) among a sample of Tehran residents. METHODS Overall, 8108 participants (3686 men) aged≥30 years, were investigated. To examine the association between risk factors and outcomes, multivariate s...

It has been demonstrated that platelet-activating factor (PAF)-acether can induce nasal neutrophilia and eosinophilia, with a different degree of responsiveness in atopic and in nonatopic subjects. The aim of this study was to evaluate whether PAF can also induce the release of secondary mediators in the human nose. Ten patients with allergic rhinitis and 10 normal subjects underwent nasal chal...

Lipid mediators are known to play important roles in the onset and resolution phases of the inflammatory response in mammals. The phospholipid platelet-activating factor (PAF) is a pro-inflammatory lipid mediator which participates in vascular- and innate immunity-associated processes by increasing vascular permeability, by facilitating leukocyte adhesion to the endothelium, and by contributing...

Isolated dog submandibular gland cells synthesize platelet-activating factor (PAF) when stimulated with acetylcholine (ACh). This production of PAF was concentration- and time-dependent, and was inhibited by pretreatment with anticholinergic agents. PAF that had accumulated in cells through prior stimulation with ACh vanished rapidly on addition of atropine. Phenylmethanesulphonyl fluoride prod...

We characterized the dose response of bovine neutrophils to platelet-activating factor (PAF) with respect to the following functions: calcium flux and membrane potential changes, actin polymerization, degranulation, and the production and/or priming of the oxidative burst. PAF at very low concentrations (10(-10) and 10(-9) M) caused changes in intracellular calcium and membrane potential in bov...