Study of the hypothalamic angiotensin system in aortic coarcted rats using the reverse microdislysis technique

HÖCHT C, OPEZZO JA, GIRONACCI M, PEÑA C, TAIRA CA.

PHARMACOLOGICAL RESEARCH

ACADEMIC PRESS LTD-ELSEVIER SCIENCE LTD

Lugar: Manchester; Año: 2003 vol. 48 p. 301 - 307

1043-6618

The objective of our work was to study the intrahypothalamic actions of irbesartan, an angiotensin receptor antagonist, on blood pressure and dopaminergic and serotoninergic neurotransmission in sham operated (SO) and aortic coarctated (ACo) rats by using the microdialysis perfusion technique. We also studied a possible enhanced pressor response to angiotensin II in aortic coarctated rats in the anterior and posterior hypothalamic area. Wistar urethane-chloralose anaesthetised rats were used. A cannula was inserted in the carotid artery. A concentric microdialysis probe was implanted into the anterior hypothalamus or posterior hypothalamus and irbesartan (6 microg ml(-1)) was perfused through the probe. Changes of mean arterial pressure (MAP) were measured. 3,4-Dihydroxyphenylacetic acid (DOPAC) and 5-hydroxyindoleacetic acid (5-HIAA) levels were measured in dialysate samples by HPLC-EC. A greater response to irbesartan perfusion in the anterior hypothalamic area of aortic coarctated rats was observed (SO rats, DMAP: -4.3+/-2.3 mm Hg; ACo rats, DMAP: -11.4+/-1.5 mm Hg, P