Association of plasma kallikrein and bradykinin receptor 1 with prognosis of cerebral infarction in elderly rats after ischemic stroke / 中华老年医学杂志

ABSTRACT

Objective:To explore the correlation of plasma kallikrein and bradykinin receptor 1 with prognosis of cerebral infarction in elderly rats after ischemic stroke.Methods:A total of 40 male Sprague-Dawley rats were randomly divided into 4 groups the stroke model group(intraperitoneally injected with 150 μl 0.9% saline, n=10), the DX-88 group(intravenously injected with kallikrein inhibitor DX-88 30 μl/time, n=10), the R-954 group(intravenously injected with bradykinin B1 receptor antagonist R-954 30 μl/time, n=10)and the DX-88 combined with R-954 treatment group(intravenously injected with DX-88 and R-954, n=10). Protein expression levels of plasma kallikrein and bradykinin receptor 1 were determined by Western blotting.mRNA expression levels of interleukin-1β(IL-1β), tumor necrosis factor-α(TNF-α)and caspase-3 were analyzed by using qRT-PCR.A neurologic function scale was used to score cerebral nerve injury and calculate the middle cerebral infarction area and cerebral swelling in experimental rats.Cerebral blood-brain barrier permeability was assessed by the cerebral infarction area.Results:Neurological injury scores decreased in the DX-88, R-954 and DX-88 + R-954 groups compared with the stroke model group(5.35±1.35, 6.49±1.16, 4.92±0.92 vs.11.17±2.18, F=15.589, P=0.022). Compared with the stroke model group, the cerebral infarction area was reduced in the DX-88, R-954 and DX-88+ R-954 groups[(4.35±1.05) mm 2, (5.43±0.26) mm 2, (3.88±0.13) mm 2vs.(8.26±1.24) mm 2, F=13.476, P=0.034)]. The extent of brain swelling was smaller in the DX-88, R-954 and DX-88+ R-954 groups than in the stroke model group[(31.28±7.45) %, (35.19±8.57) %, (19.68±3.14) % vs.(74.26±15.66) %, F=16.587, P=0.026)]. Plasma kallikrein protein levels were lower in the DX-88 and DX-88+ R-954 groups than in the stroke model group( P<0.05). The expression of bradykinin-1 receptor mRNA was lower in the R-954 and DX-88+ R-954 groups than in the stroke model group( P<0.05). The above results indicated that antagonism of plasma kallikrein and bradykinin receptor 1 played an important role.mRNA transcription levels of IL-1β, TNF-α and caspase-3 were higher in the stroke model group than in the DX-88, R-954 and DX-88+ R-954 groups( F=12.665、14.574 and 13.665, P=0.021、0.015 and 0.003). Conclusions:Inhibiting plasma kallikrein and bradykinin receptor 1 may provide protection against cerebral nerve injury in cerebral ischemia, and improve the prognosis of cerebral infarction.