@entity741 is a complex process leading to the simultaneous release of a number of mediators, including @entity2404 (TxA(2)) and @entity1812 (BK), that activate cardiac spinal afferents. The present study tested the hypothesis that @entity3447 and BK reciprocally interact to excite @entity63 sensitive cardiac afferents. Nerve activity of single cardiac afferent units was recorded from the left sympathetic chain or rami communicantes (T(2)-T(5)) of anesthetized @entity468 . Fifty-two @entity63 sensitive afferents (conduction velocity = 0.27-3.35 m/s, 7 Adelta-fibers and 45 C-fibers) were identified. Repeated injections (1 microg) of BK into the left atrium (LA) 4 min after the administration of @entity2872 (5 microg into the LA), a TxA(2) mimetic, induced a significantly larger cardiac afferent response than the first response to BK (0.61 +/- 0.14 to 1.95 +/- 0.29 vs. 0.66 +/- 0.09 to 2.75 +/- 0.34 impulses/s, first injection vs. second injection, n = 8). Conversely, blockade of TxA(2) receptors with BM-13,177 (30 mg/kg iv) attenuated the responses of eight other afferents to BK (1 microg into the LA) by 45%. In contrast, repeated BK (1 microg into the LA) induced consistent discharge activity in six separate afferents. We then observed that the coadministration of @entity2872 (5 microg) and BK (1 microg into the LA) together caused a total response that was significantly higher than the predicted response by the simple addition of the individual responses. BK (1 microg) facilitated eight cardiac afferent responses to @entity2872 (5 microg into the LA) by 64%. In contrast, repeated @entity2872 (5 microg into the LA) without intervening BK stimulation evoked consistent responses in seven other @entity63 sensitive afferents. Finally, inhibition of cyclooxygenase with @entity3352 (5 mg/kg iv) eliminated the potentiating effects of BK on the cardiac afferent response to @entity2872 (5 microg into the LA) but did not alter the afferent response to @entity2872 . These data suggest that BK and TxA(2) reciprocally interact to stimulate @entity63 sensitive cardiac afferent endings leading to synergistic afferent responses and that the BK sensitization effect is mediated by cyclooxygenase products.

@entity1812 and XXXX reciprocally interact to synergistically stimulate cardiac spinal afferents during @entity741 .

@entity3447 :: ('CHEBI:15627', 'Chemical') :: ['TxA(2)'] @entity63 :: ('MESH:D007511', 'Disease') :: ['ischemically'] @entity2404 :: ('MESH:D013928', 'Chemical') :: ['thromboxane A(2)'] @entity2872 :: ('MESH:D019796', 'Chemical') :: ['U-46619'] @entity741 :: ('MESH:D017202', 'Disease') :: ['Myocardial ischemia'] @entity1812 :: ('MESH:D001920', 'Chemical') :: ['bradykinin'] @entity3352 :: ('MESH:D007213', 'Chemical') :: ['indomethacin'] @entity468 :: ('9685', 'Species') :: ['cats']
@entity2404 :: (MESH:D013928,Chemical) :: ['thromboxane A2']
