Role of bradykinin in the vascular permeability response induced by carrageenin in rats

Abstract

1Bradykinin in carrageenin-induced inflammatory pouch fluid was measured by an enzyme immunoassay method. 2 The bradykinin showed a single peak in the 30-60min period after the challenge and then decreased quickly, and there was a correlation between the bradykinin level and exudation of fluorescein-labelled bovine serum albumin in the first 60 min period. 3 Captopril (an inhibitor of kininase II) elevated both the bradykinin level in the inflammatory pouch fluid and vascular permeability, while DL-2-mercaptomethyl-3-guanidinoethylthiopropanoic acid (an inhibitor of kininase I) had no effect. 4 Soybean trypsin inhibitor (SBTI) inhibited the vascular permeability response in parallel with the decrease in the bradykinin level. 5 A bradykinin-degrading activity appeared in the pouch fluid within 1 h after the challenge and increased with time. 6 In the period of 3.5-4 h, bradykinin levels were suppressed below the sensitivity limit of the assay, i.e. 0.07 ng ml 1, in spite of active generation. This was because degradation of bradykinin was very rapid in this late stage. Nevertheless, bradykinin still played a definite role in sustaining a high level of vascular permeability response in the late stage in conjunction with prostaglandins.

Kinins and peritoneal exudates induced by carrageenin and zymosan in rats

“…(1962), the inflammatory reactions induced in rats by carrageenin are considered the conventional model to detect anti-inflammatory drugs. The presence of kinins, endogenous pro-inflammatory peptides, in the fluids withdrawn from carrageenin-induced inflammatory reactions has been demonstrated in a few studies (Willis, 1969;Capasso et al, 1975;Barlas et al, 1985;Kumakura et al, 1988;Katori et al, 1989;Adam et al, 1989), but there is much circumstantial evidence which indicates that kinins could play a major role in the development of these inflammatory reactions (reviewed in Damas & RemacleVolon, 1981). Several attempts have been made to develop other inflammatory models.…”

Role of Bradykinin in Exudative Reactions of Inflammation in Rats

“…Consequently, the time course studies could be done to demonstrate a close correlation between bradykinin levels and plasma exudation in both of the experimental inflammations, which were induced by carrageenin and kaolin, respectively [7,8],…”

“…Observations collected from the above series of experi ments have been already reported elsewhere [7][8][9][10]. The purpose of the present article is to review data obtained in this laboratory.…”

“…Permeability and Bradykinin Levels SBTI, a potent inhibitor of plasma kallikrein, appeared to block bradykinin generation almost completely in both the kaolin and carrageenin inflammations, since local ap plication of SBTI reduced markedly both the bradykinin levels and vascular permeability responses [7,8], Moreover, local application of kininase inhibitors in addi tion to SBTI caused no significant increase in bradykinin levels nor vascular permeability, while kininase inhibitors, especially captopril, i.e. an inhibitor of kininase II, brought about a marked increase both in the bradykinin levels and vascular permeability in the absence of SBTI.…”

“…202 from Marine Colloid Inc.. N.J.. USA) in saline (8] or a suspension of kaolin (10 mg/ml) in 0.8% (w/v) carboxymethylcellulose solution [7] into the air pouch preformed 24 h before by injecting air (8.0 ml) subcutaneously on the back of specific pathogen-free. 6-week-old male Sprague-Dawley rats.…”