PURPOSE To assess the effects of K(+)-channel blockers on bradykinin-induced relaxations in porcine ciliary artery. METHODS Vascular isometric forces were measured with a myograph system. Ciliary vascular rings were precontracted with thromboxane A2 analog (U 46619, 10(-7) M) to assess dose-dependent (10(-10)-3 x 10(-6) M) bradykinin-induced relaxation after addition of one of the following: ...

Electrical stimulation of afferent renal nerves and activation of renal mechanoreceptors increase plasma vasopressin concentrations. In the present study, the effect of renal chemoreceptor activation on plasma vasopressin concentration was investigated in anesthetized rabbits. Renal chemoreceptors were activated with intrarenal infusions of bradykinin. With intrarenal infusion of bradykinin at ...

The present study examined the role of intrarenal bradykinin in angiotensin-converting enzyme inhibitor (ACEI)-induced dilation of renal afferent (AFF) and efferent arterioles (EFF) in vivo, and further evaluated whether ACEI-stimulated bradykinin activity differed in superficial (SP) and juxtamedullary nephrons (JM). Arterioles of canine kidneys were visualized with an intravital charge-couple...

Bradykinin is an important mediator in blood pressure regulation, ischemic precondition and capillary leakage, allergy, anaphylaxis, inflammation, and nociception, at least partly via the generation of nitric oxide (NO). Macrophages are particularly abundant in the porcine lung circulation. Upon bradykinin binding macrophages release cytokines and endothelial cells increase plasma leakage. Both...

Angiotensin-converting enzyme (ACE) plays a central role in the renin-angiotensin system. Whereas ACE is responsible for the production of angiotensin II, it is also important in the elimination of bradykinin. Constitutively, the biological function of bradykinin is mediated through the bradykinin B(2) receptor. ACE knockout mice have a complicated phenotype including very low blood pressure. T...

We recently identified a vagally mediated excitatory lung reflex by injecting hypertonic saline into the lung parenchyma (Yu J, Zhang JF, and Fletcher EC. J Appl Physiol 85: 1485-1492, 1998). This reflex increased amplitude and burst rate of phrenic (inspiratory) nerve activity and suppressed external oblique abdominal (expiratory) muscle activity. In the present study, we tested the hypothesis...

Angiotensin-converting enzyme (ACE) inhibitors reduce the progression of various fibrotic renal diseases both in humans and in animal models. Unilateral ureteral obstruction (UUO) is an animal model of accelerated renal tubulointerstitial fibrosis that is attenuated by ACE inhibition. Although ACE inhibitors increase bradykinin concentrations in addition to their effect on angiotensin II format...

Bradykinin produced at sites of tissue injury and inflammation elicits acute pain and alters the sensitivity of nociceptive neurons to subsequent stimuli. We tested the hypothesis that bradykinin could elicit long-lasting changes in nociceptor function by activating members of the nuclear factor of activated T-cells (NFAT) family of transcription factors. Bradykinin activation of B2 receptors e...

The goal of the present study was to determine if voltage-sensitive calcium channels are present in bovine aortic endothelial cell plasmalemma and if they contribute to the rise in cytosolic calcium produced by bradykinin. After bradykinin (100 nM) exposure, endothelial cell associated fura-2 fluorescence peaked within 10-20 seconds and then declined to a steady level 2- to 3-fold above resting...

These experiments were designed to analyze the interaction of a bradykinin antagonist with prostaglandins in blood pressure regulation of normotensive rats. Male Wistar rats, divided into three groups, received a 5-minute intra-arterial infusion of the bradykinin antagonist [( DArgo-Hyp3-Thi5,8-DPhe7]BK-TFA) at 250 micrograms/min. Groups were either intact rats (group I, n = 5), pretreated with...