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Thromboxane Contributes to the Exercise Pressor Reflex in Simulated Peripheral Artery Disease
Author(s) -
Leal Anna Katherine,
McCord Jennifer L,
Tsuchimochi Hirotsugu,
Kaufman Marc P
Publication year - 2011
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.25.1_supplement.1056.9
Subject(s) - reflex , medicine , femoral artery , peripheral , hindlimb , thromboxane a2 , anesthesia , contraction (grammar) , cardiology , receptor
The exercise pressor reflex is exaggerated in rats with simulated peripheral artery disease. The sensory arm of this reflex is comprised of group III and IV afferents, which have been shown to be both sensitized and stimulated by thromboxane A 2 (TxA 2 ). Using decerebrate rats, we tested the hypothesis that TxA 2 contributed to the exaggerated exercise pressor reflex occurring in peripheral artery disease, which was simulated by ligating the femoral artery 72 hours prior to experimentation. We measured the cardiovascular responses to static hindlimb contraction before and after iliac arterial injection of daltroban (80 μg), a TxA 2 receptor antagonist. In eight rats whose hindlimb muscles were freely perfused, the pressor‐cardioaccelerator responses to contraction were reduced by daltroban, averaging 13 ± 2 mmHg and 4 ± 1 bpm before and 4 ± 2 mmHg and 0 ± 2 bpm afterwards (both P<0.05). In eight rats whose femoral arteries were ligated, the pressor‐cardioaccelerator responses to contraction were also reduced by TxA 2 eceptor blockade, averaging 25 ± 3 mmHg and 8 ± 1 bpm before and 10 ± 2 mmHg and 4 ± 1 bpm afterwards (both P<0.05). Our findings suggest TxA 2 contributes to both the exaggerated exercise pressor reflex seen in peripheral artery disease as well as to the reflex evoked from normally perfused muscles.