Therapeutical efficacy of a novel non-peptide bradykinin B2 receptor antagonist on brain edema formation and ischemic tissue damage in focal cerebral ischemia.

OBJECTIVE: Bradykinin has been identified as a mediator of secondary brain damage in acute insults. We currently studied neuroprotective properties of a bradykinin B2 receptor antagonist (LF16-0687 Ms) in transitory focal cerebral ischemia to assess infarct formation and the development of brain edema.
MATERIAL AND METHODS: 55 Rats were subjected to 90 min of MCA-occlusion. The receptor antagonist was administered at two dose levels, given from 30 min prior to ischemia over two days after ischemia. Ischemic tissue damage was quantified at day 7 after MCA-occlusion together with assessment of brain edema in separate experiments. Neurological recovery was studied daily.
RESULTS: Animals receiving treatment (low dose) had a better functional recovery, particularly at days 3 and 4 (P < 0.05). Infarct formation was significantly attenuated in these animals in both total and cortical brain tissue by 50, or 80%, respectively. Postischemic brain swelling was significantly lowered, i.e. by 62%.
CONCLUSIONS: Our findings provide further support for a mediator role of bradykinin in ischemic brain damage including edema formation, obviously by ligand binding to the bradykinin B2 receptor. The availability of a receptor antagonist may afford opportunity for translation of this experimental treatment into stroke patients.