Intrathecal administration of Ang (1-7) dose-dependently inhibited Ang II-induced nociceptive behaviour and p38 MAPK phosphorylation in mice, an effect mediated through Mas receptors.
Does intrathecal Angiotensin (1-7) prevent Angiotensin II-induced nociceptive behaviour in mice?
Intrathecal Ang (1-7) attenuates Ang II-induced nociceptive behavior in mice by inhibiting p38 MAPK phosphorylation via Mas receptors.
BACKGROUND: We have recently demonstrated that intrathecal (i.t.) administration of angiotensin II (Ang II) induces nociceptive behaviour in mice accompanied by a phosphorylation of p38 mitogen-activated protein kinase (MAPK) mediated through Ang II type 1 (AT1 ) receptors. The N-terminal fragment of Ang II, Ang (1-7), plays a pivotal role in counterbalancing many of the well-established actions induced by Ang II. However, the role of Ang (1-7) in spinal nociceptive transmission remains unclear. Therefore, we examined whether i.t. administration of Ang (1-7) can inhibit the Ang II-induced nociceptive behaviour in mice. METHODS: In the behavioural experiments, the accumulated response time of nociceptive behaviour consisting of scratching, biting and licking in conscious mice was determined during a 25-min period starting after i.t. injection. The distribution and localization of AT1 or Mas receptors were analysed using a MapAnalyzer and confocal microscope, respectively. Phosphorylation of p38 MAPK in the dorsal spinal cord was measured by Western blotting. RESULTS: The nociceptive behaviour induced by Ang II was dose-dependently inhibited by the co-administration of Ang (1-7). The inhibitory effect of Ang (1-7) was reversed by the co-administration of A779, a Mas receptor antagonist. Western blot analysis showed that the increase in spinal p38 MAPK phosphorylation following the i.t. administration of Ang II was also inhibited by Ang (1-7), and the Ang (1-7) induced-inhibition was prevented by A779. CONCLUSIONS: Our data show that the i.t. administration of Ang (1-7) attenuates an Ang II-induced nociceptive behaviour and is accompanied by the inhibition of p38 MAPK phosphorylation mediated through Mas receptors.
Nemoto et al. (Tue,) conducted a other in Nociceptive behaviour. Angiotensin (1-7) vs. Angiotensin II alone / A779 co-administration was evaluated on Accumulated response time of nociceptive behaviour (scratching, biting, licking) and phosphorylation of p38 MAPK. Intrathecal administration of Ang (1-7) dose-dependently inhibited Ang II-induced nociceptive behaviour and p38 MAPK phosphorylation in mice, an effect mediated through Mas receptors.