Title: The kallikrein-kinin system in ischemic and traumatic brain injury
Abstract: The surgeon Emil Karl Frey and the physiologist Heinrich Kraut, both working at the Ludwig-Maximilians University in Munich at that time, were first to describe the existence of the kallikrein-kinin system in 1928 [1]. The initial observation was that injection of urine into the circulation of anesthetized dogs had a marked hypotensive effect. The hypotension caused by peripheral vasodilation turned out to be induced by a family of proteins later named kinins [2]. Today we know that the most abundant kinins are the nonapeptide bradykinin (Argl-Pro2-Pro3-Gly4-PhesSer6-Pro7-Phe8-Arg9), its degradation product des-Arg9-bradykinin, and the dekapeptide kallidin (Lys°-bradykinin) [3]. Bradykinin is mainly found in plasma where it is cleaved from its pre-cursor high molecular weight (HMW) kininogen (MW 120 kDa) by the plasma protease kallikrein (90 kDa) (Fig. 1). Kallidin is predominantly found in tissue and is cleaved from low molecular weight (LMW) kininogen (68 kDa) by a low molecular weight kallikrein (30 kDa) only found in tissue. Activation of the kallikrein-kinin system occurs by conversion of the inactive pre-kallikrein to active kallikrein by several proteins acting as kallikreinases, e.g., Hagman factor (blood clotting factor XII), trypsine, thrombin, plasmine, or C1-esterase, which accumulate at the site of endothelial and tissue injury. Interestingly, kinin production can also occur independently of kallikrein activation by cellular proteases released from mast cells or granulocytes [4].
Publication Year: 2001
Publication Date: 2001-01-01
Language: en
Type: book-chapter
Indexed In: ['crossref']
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Cited By Count: 2
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