Disfunción de las catecolaminas en la medula adrenal de la rata durante la hipertensión y su tratamiento con captopril

Resum

We have investigated the alteration of catecholamines biosynthetic enzymes and chromogranin A (ChA) expression in the adrenal medulla of spontaneously hypertensive rats (SHR) and its variation with the captopril treatment. We have used adrenal glands from male rats divided into four groups: a control (WKY), a WKY group treated with captopril (WKY-T), a hypertensive group (SHR) and a hypertensive treated (SHR-T) groups. Rats were sacrificed at 8, 10 and 15 weeks of age. Antibody against the tyrosine-hydroxylase (TH), dopamine beta-hydroxylase (DBH), Phenyl-ethanolamine N-methyl-transferase (PNMT) and chromogranin A (ChA) were used for the western blot and immunocytochemical study. In the adrenal gland, the ChA and TH were increased in the SHR groups, but captopril treatment produced an increase in both control and hypertensive groups. While dopamine beta-hydroxylase and PNMT activity, in SHR, was slightly lower to those WKY and the captopril treatment produced an increase in the intensity of the DBH reaction in hypertensive group with respect to the untreated hypertensive group. We could conclude that over-expression of ChA and the alteration found in the different enzymes of catecholamines biosynthesis in the adrenal medulla is a feature of spontaneously hypertension, a fact, which could be modified by captopril treatment.