A new writhing model of factor XII activator-induced pain for assessment of non-steroidal anti-inflammatory agents. I. Kaolin-induced writhing in mice.

Demonstration of Kinin-Release in the Peritoneal Exudate of Kaolin-Induced Writhing in Mice

“…The above finding is consistent with the previous report in which the captopril-induced writhing reaction (later stage) was also completely suppressed by simultaneous injection of SBTI (1,2).…”

“…Accordingly, it is suggested that there is some threshold of peritoneal kinin level for en hancing the writhing reaction, and the sensitizing action of PG12 is an indispensable factor in this reaction. Furthermore, at 60 min after kaolin in jection, the writhing reaction could be induced by intraperitoneal injection of cap topril (later stage) as previously reported (1,2). The kinin amount in the peritoneal washings 5 min after the captopril (20 iig/ mouse) injection was also measured and shown in Table 2.…”

“…The writhing response was observed (early stage) as previously reported (1,2). The writhing reaction of later stage was induced by intra peritoneal injection of captopril (Sankyo) (20 ,og/0.2 ml saline/mouse) at 60 min after the kaolin injection as previously reported (1,2).…”

“…Recently, we have developed a new pain model in mice by using the kaolin-induced writhing reaction (1). A possible mechanism for the induction of writhing is that bradykinin could be released through the activation of factor XII by kaolin and causes the pain reaction.…”

Differential sensitivity of antinociceptive assays to the bradykinin antagonist Hoe 140

“…The proportion of the response that was sensitive to Hoe 140 was similar to both assays. It has previously been reported that the kaolininduced abdominal constriction response is abolished by soyabean trypsin inhibitor, a non-specific kallikrein inhibitor (Fujiyoshi et al, 1989c). This would imply that the response is almost entirely due to BK.…”