Premium
Bradykinin B2 receptor contributes to exaggerated muscle mechanoreflex in rats with femoral artery occlusion
Author(s) -
Lu Jian,
Xing Jihong,
Li Jianhua
Publication year - 2013
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.27.1_supplement.699.11
Subject(s) - bradykinin , medicine , endocrinology , reflex , femoral artery , receptor , kinin , blood pressure , ligation , hindlimb , mean arterial pressure , chemistry , heart rate
In peripheral artery disease (PAD), amplified sympathetic nerve activity (SNA) and blood pressure (BP) responses to static exercise are observed. This dysfunction of the exercise pressor reflex is mediated, in part, by muscle mechanoreflex overactivity. Prior studies suggest that bradykinin B2 receptor mediates the reflex SNA and BP responses during the exercise pressor reflex. Thus, we determined if kinin B2 receptor contributes to the augmented mechanoreflex activity in rats with PAD induced by 24 hrs of femoral artery ligation. First, western blot analysis showed that protein expression of B2 displays significant over‐expression in dorsal root ganglion of ligated limbs as compared with control limbs (optical density: 0.94 ± 0.02 in control and 1.87 ± 0.08 after ligation, P < 0.05 vs. control; n = 6 in each group). Second, mechanoreflex was evoked by passive tendon stretch and the reflex renal SNA and BP responses to stretch were examined after arterial injection of HOE‐140 (a B2 receptors blocker) into the hindlimb. HOE‐140 had greater attenuating effects on SNA and BP in ligated rats. i.e. after 5 μg/kg of HOE‐140 renal SNA and BP responses evoked by 0.5 kg of muscle tension were attenuated by 43% and 25% in control vs. 54% and 34% in ligation ( P < 0.05 vs. control group; n=11 in each group). In contrast, there is no significant difference in B1 expression in both experimental groups, and arterial injection of R‐715, a B1 receptors blocker, had no significant effects on SNA and BP responses evoked by muscle stretch. Accordingly, results obtained from this study support our hypothesis that heightened kinin B2 expression in the sensory nerves contributes to the exaggerated muscle mechanoreflex in PAD rats. (Supported by NIH P01 HL096570 & AHA EIA 0840130N)