Interaction between Mas and the angiotensin AT1 receptor in the amygdala

The Mas-protooncogene is a maternally imprinted gene encoding an orphan G p rotein-coupled receptor expressed mainly in limbic structures of the rodent CNS. Because Mas and the product of the Mas-related gene enhance the effec ts of angiotensins on cells expressing angiotensin receptors of the AT1 sub type, we first compared the distribution of cells expressing AT1 receptors in different limbic and thalamic brain structures in Mas-knockout mice and in wildtype mice by an immunohistochemical approach. No significant differe nces could be found between the two strains. The Mns-protooncogene seems to be implicated in the signal transduction of angiotensin receptors and is e xpressed in the amygdala. Therefore we then analyzed whether field potentia ls are altered by angiotensin II in brain slices of the basolateral amygdal a. An opposite action of angiotensin II was obtained in mice lacking the Ma s-protooncogene in comparison to wildtype mice. The use of different angiot ensin receptor antagonists provides the first in vitro evidence for a funct ional interaction between the Mas-protooncogene and the AT1 receptor.