Hypoalgesia and altered inflammatory responses in mice lacking kinin B1 receptors

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Item Type:	Article
Title:	Hypoalgesia and altered inflammatory responses in mice lacking kinin B1 receptors
Creators Name:	Pesquero, J.B., Araujo, R.C., Heppenstall, P.A., Stucky, C.L., Silva, J.A., Walther, T., Oliveira, S.M., Pesquero, J.L., Paiva, A.C.M., Calixto, J.B., Lewin, G.R. and Bader, M.
Abstract:	Kinins are important mediators in cardiovascular homeostasis, inflammation, and neciception. Two kinin receptors have been described, B1 and B2. The B2 receptor is constitutively expressed, and its targeted disruption leads to salt-sensitive hypertension and altered nociception. The B1 receptor is a heptahelical receptor distinct from the B2 receptor in that it is highly inducible by inflammatory mediators such as bacterial lipopolysaccharide and interleukins. To clarify is physiological function, we have generated mice with a targeted deletion of the gene for the B1 receptor. B1 receptor-deficient animals are healthy, fertile, and normotensive. In this mice, bacterial lipopolysaccharide-induced hypotension is blunted, and there is a reduced accumulation of polymorphonuclear leukocytes in inflamed tissue. Moreover, under normal noninflamed conditions, they are analgesic in behavioral test of chemical and thermal nociception. Using whole-cell patch- clamp recordings, we show that the B1 receptor was not necessary for regulating the noxious heat sensitivity of isolated nociceptors. However, by using an in vitro preparation, we could show that functional B1 receptors are present in the spinal cord, and their activation can facilitate a nociceptive reflex. Furthermore, in B1 receptor-deficient mice, we observed a reduction in the activity-dependent facilitation (wind-up) of a nociceptive spinal reflex. Thus, the kinin B1 receptor plays an essential physiological role in the initiation of inflammatory responses and the modulation of spinal cord plasticity that underlines the central component of pain. The B1 receptor therefore represents a useful pharmacological target especially for the treatment of inflammatory disorders and pain.
Keywords:	Afferent Neurons, Blood Pressure, Bradykinin B1 Receptor, Bradykinin Receptors, Chemical Stimulation, Electric Stimulation, Heat, Inflammation, Knockout Mice, Pain, Pain Threshold, Reflex, Spinal Cord, Animals, Mice
Source:	Proceedings of the National Academy of Sciences of the United States of America
ISSN:	0027-8424
Publisher:	National Academy of Sciences
Volume:	97
Number:	14
Page Range:	8140-8145
Date:	5 July 2000
Official Publication:	https://doi.org/10.1073/pnas.120035997
PubMed:	View item in PubMed

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