Angiotensin II Receptor expression is regulated during fetal development.

MANZUR MJ, CIUFFO GM

Bariloche, Rio Negro-Argentina

Workshop; Combined meetings: “Gene Expression and RNA Processing” and “Cell Biology, Signaling and Alternative Splicing”.; 2007

ICGEB, EURASNET,AGENCIA

ANGIOTENSIN II RECEPTOR EXPRESSION IS REGULATED DURING FETAL DEVELOPMENT Manzur María J, and Ciuffo Gladys M. Bioquímica Avanzada. Fac. Qca, Bioqca y Fcia. UNSL. Ejército de los Andes 950 (5700) San Luis.  E-mail: mjmanzu@unsl.edu.ar Angiotensin II plays an important role in regulation of cardiovascular haemodynamic and growth, through binding to membrane receptors. Two distinct receptor subtypes have been identified and classified by their pharmacological characteristics as AT1 and AT2 receptors. Ang II receptor expression is highly modulated during development suggesting a role of these receptors in growth and organogenesis, and for that reason we analyze the pattern of gene expression of both receptors during rat fetal development by RT-PCR and Northern blot. mRNAs of rat hindbrain and whole fetuses at different embryonic stages (E13 to E20) were analyzed. In whole fetuses the expression of AT2 receptors is detectable from gestation day 13 being maximum in the stage E20. AT1 expression was low at all developmental stages. In rat hindbrain we did not find expression of AT1 R at E16 and E18, and a low expression level was observed at E19. In fetal rat hindbrain, low expression of AT2 receptors was present at E16 and increases during development. RT-PCR results correlate with those from Northern blot and are in agreement with previous observations by binding autoradiography. The above mentioned results support a possible inter-regulation between the two receptors. In order to study the interaction between AT1 and AT2 receptors we design a co-transfection experiment to express both receptors in a cell line. It is well-known that cerebellar development in the rat initiates at the final embryonic stage and last for 2-3 weeks after birthday, in agreement with the low level of Ang II receptor expression observed on these structures. The present results support the hypothesis of a potential role of Ang II receptors on development and organogenesis.