Arachidonic acid metabolites in carrageenin‐induced equine inflammatory exudate

Abstract

The presence of cyclooxygenase products of arachidonic acid metabolism in carrageenin-induced inflammatory exudate was investigated in ponies using two models. In the first model, an inflammatory response was stimulated by injecting carrageenin into subcutaneously implanted polypropylene tissue cages and exudates were collected at five predetermined times between 3 and 48 h. In the second model, exudates were harvested at 6, 12 and 24 h from carrageenin-impregnated polyester sponges which had also been inserted beneath the skin. Prostaglandin (PG) E2, thromboxane (TX) B2 and the stable breakdown-product of prostacyclin (PGI2), 6-keto-PGF1 alpha, in exudates were measured by radio-immunoassay (RIA); PGE2-like and PGF2 alpha-like activities were bioassayed following an acid-lipid extraction technique which provided a recovery rate of 78%. Agreement between RIA and bioassay was within acceptable limits. In Model 1, using RIA, mean PGE2 concentration reached 197 ng X ml-1 at 12 h decreasing to less than 12 ng X ml-1 at 24 h. Mean TXB2 and 6-keto-PGF1 alpha levels were highest at 48 h (22.3 and 34.2 ng X ml-1, respectively) after considerable fluctuations and with wide standard errors prior to this time. In the sponge model, however, PGE2 levels were surprisingly low for each group (mean 12.8 ng X ml-1 at 12 h) and TXB2 and 6-keto-PGF1 alpha were similarly lower (means of 3.3 and 8.1 ng X ml-1 respectively at 12 h). Mean total leucocyte counts and total protein concentrations were increased in both models after carrageenin stimulus. PGF2 alpha was not detected in measurable quantities in any exudate.(ABSTRACT TRUNCATED AT 250 WORDS)

A pharmacodynamic and pharmacokinetic study with vedaprofen in an equine model of acute nonimmune inflammation

“…A mild inflammatory response was induced in the neck of each pony (period 1: left; period 2: right) by insertion of five polyester sponge strips (25 × 25 × 5 mm) soaked in sterile 1% carrageenan solution into subcutaneous pouches dissected under local anaesthesia (2% lignocaine hydrochloride, Lignocaine and Adrenaline Solution, Norbrook Laboratories Ltd, Newry, N. Ireland) (Higgins & Lees, 1984) and these were removed serially at predetermined times up to 8 h. Five further sponges soaked in 1% sterile carrageenan solution were then inserted.…”

The effects of lipopolysaccharide and interleukins-1alpha, -2 and -6 on oxytocin receptor expression and prostaglandin production in bovine endometrium

“…The method used for the PGF 2 and PGE 2 assays was similar to that described previously by Higgins & Lees (1984). Briefly, the medium was diluted 100-fold with Tris-HCl buffer (40 mM, pH 7·4).…”

Actions of BW540C in an equine model of acute inflammation: A preliminary study

“…The data were not subjected to statistical analysis, however, because of 'the small number of ponies in each treatment group. The high concentration of protein in exudates and the rise in skin temperatures presumably reflect and are a measure of the acute inflammatory reaction induced by carrageenin and mediated in part by eicosanoids (6). Although only six ponies were used in this investigation, it has been possible to demonstrate for the first time increases in skin temperature over the site of a lesion in a carrageenin-sponge model of acute inflammation.…”

“…The ponies were divided into two equal groups, matched for weight, housed in individual loose-boxes and bedded on inedible wood chippings. A localised and well-tolerated acute inflammatory reaction was generated in the neck of each animal by implanting, under local anaesthesia (2% lignocaine hydrochloride), five sterile polyester sponge strips (50x25x5 mm) soaked in a 2% solution of carrageenin (Sigma Chemical Company, Poole, Dorset) in the manner described previously (6,8).…”

“…In this paper, we describe the further development of a previously reported carrageeninsponge model of acute non-immune inflammation in the horse (6,8). The model has been used in a preliminary study of the actions of the novel anti-inflammatory agent BW540C (3-methylamino-1-(3-trifluoromethyl)-pheny1-2-pyrazoline) (Wellcome Research Laboratories).…”