Experiments were undertaken to characterise the action of kinins on sympathetic neurones of the rat superior cervical ganglion (SCG) by use of in vitro grease-gap, extracellular recording techniques in conjunction with selective agonists and antagonists for B1 and B2 bradykinin (BK) receptors. Superfusion of BK (10 nM to 10 microM) to the ganglion produced a concentration-related depolarisation (pD2 = 7.02 +/- 0.04, n = 7) which was inhibited by the selective B2 antagonist HOE 140 (10-100 nM), but not by the B1 antagonist Leu8desArg9 BK (1 microM), indomethacin (7 microM) or the nitric oxide synthase inhibitor L-NG-nitroarginine methyl ester (300 microM). DesArg9BK (10 nM to 10 microM) had no effect on membrane potential. Pre-treatment of animals with intravenous bacterial lipopolysaccharide (LPS, 3 mg kg-1) failed to induce B1 receptor-mediated depolarisations of SCG neurones, or change responses to BK (P > 0.05, n = 4). These experiments highlight and characterise the action of BK as a neuromodulator of sympathetic neurones via B2 receptor activation.