Angiotensin II AT2 receptor blocker reverse the neuroprotective action of preconditioning in the brain of hypoxic ischemic neonatl rats

LOPEZ AGUILERA, F; BIAGGIO, VS; AYALA, C; SELTZER, AM.

Cordoba- Huerta Grande

Congreso; XXVI Congreso Anual de la Sociedad Argentina de Neurociencias; 2011

XXVI Congreso Anual de la Sociedad Argentina de Neurociencias

AT2 receptors (AT2-R) are involved in the control of cell proliferation and tissue regeneration. In a previous report we observed that AT-R were up-regulated in the preconditioned neonatal brain after ischemia, and their activation could be neuroprotective contributing to the beneficial effects of AT1 receptor antagonists on neurological outcome of cerebral ischemia. Seven-day old WKY rats pups were submitted to preconditioning (PC) and then to common carotid unilateral artery ligation (l)/2mm asphyxia on day 8(H). The lesioned group (L) was submitted only to I/H. A third group was PC+/H and injected 5 ul of PD123319 (1.69mM) in the lateral ventricle after PC. Control animals received mock treatment. The animals were sacrificed at 7 days post lesion (PND15). Ki67 (a marker of cell proliferation) and GFAP (reactive astrocytes) were analyzed by IHQ (dab). The treatment with AT2 blocker reversed the effects of preconditioning, increasing the GFAP + label (p