Abnormalities of the hippocampus are similar in doca-salt hypertensive rats and spontaneously hypertensive rats.

PIETRANERA, LUCIANA; FLAVIA EUGENIA SARAVIA; ROIG, PAULINA; LIMA, A; DE NICOLA, ALEJANDRO F

JOURNAL OF NEUROENDOCRINOLOGY.

Año: 2006 vol. 18 p. 466 - 474

0953-8194

Abnormalities of the Hippocampus are Similar in Deoxycorticosterone Acetate-Salt Hypertensive Rats and Spontaneously Hypertensive Rats L. Pietranera*† *Laboratory of Neuroendocrine Biochemistry, Instituto de Biología y Medicina Experimental, Buenos Aires, Argentina. †Department of Biochemistry, Faculty of Medicine, University of Buenos Aires, Buenos Aires, Argentina., F. Saravia*† *Laboratory of Neuroendocrine Biochemistry, Instituto de Biología y Medicina Experimental, Buenos Aires, Argentina. †Department of Biochemistry, Faculty of Medicine, University of Buenos Aires, Buenos Aires, Argentina., M. C. Gonzalez Deniselle*† *Laboratory of Neuroendocrine Biochemistry, Instituto de Biología y Medicina Experimental, Buenos Aires, Argentina. †Department of Biochemistry, Faculty of Medicine, University of Buenos Aires, Buenos Aires, Argentina., P. Roig* *Laboratory of Neuroendocrine Biochemistry, Instituto de Biología y Medicina Experimental, Buenos Aires, Argentina., A. Lima* *Laboratory of Neuroendocrine Biochemistry, Instituto de Biología y Medicina Experimental, Buenos Aires, Argentina. and A. F. De Nicola*†‡ *Laboratory of Neuroendocrine Biochemistry, Instituto de Biología y Medicina Experimental, Buenos Aires, Argentina. †Department of Biochemistry, Faculty of Medicine, University of Buenos Aires, Buenos Aires, Argentina. ‡Instituto Universitario de Ciencias de la Salud, Fundación Barceló, Buenos Aires, Argentina. ·         *Laboratory of Neuroendocrine Biochemistry, Instituto de Biología y Medicina Experimental, Buenos Aires, Argentina. †Department of Biochemistry, Faculty of Medicine, University of Buenos Aires, Buenos Aires, Argentina. ‡Instituto Universitario de Ciencias de la Salud, Fundación Barceló, Buenos Aires, Argentina. Dr Alejandro F. De Nicola, Instituto de Biologia y Medicina Experimental, Obligado 2490, 1428 Buenos Aires, Argentina (e-mail: denicola@dna.uba.ar). Abstract Hippocampal neuropathology is a recognised feature of the brain in spontaneously hypertensive rats (SHR), but similar studies are lacking in another model of hypertension, the mineralocorticoid-salt-treated rat. The present study aimed to compare changes in hippocampal parameters in 16-week-old male SHR (blood pressure approximately 190 mmHg) and their normotensive Wistar-Kyoto controls, with those of male Sprague-Dawley rats receiving (i) 10 mg deoxycorticosterone acetate (DOCA) every other day during 3 weeks and drinking 1% NaCl solution (blood pressure approximately 160 mmHg) and normotensive controls treated with (ii) DOCA and drinking water, (iii) drinking water only or (iv) 1% NaCl only. In these experimental groups, we determined: (i) cell proliferation in the dentate gyrus (DG) using the 5-bromo-2´-deoxyuridine-labelling technique; (ii) the number of glial fibrillary acidic protein (GFAP) positive astrocytes under the CA1, CA3 and DG; (iii) the number of apolipoprotein E (ApoE) positive astrocytes as a marker of potential neuronal damage; and (iv) the number of neurones in the hilus of the DG, taken as representative of neuronal density in other hippocampal subfields. Changes were remarkably similar in both models, indicating a decreased cell proliferation in DG, an increased number of astrocytes immunopositive for GFAP and ApoE and a reduced number of hilar neurones. Although hypertension may be a leading factor for these abnormalities, endocrine mechanisms may be involved, because hypothalamic-pituitary function, mineralocorticoid receptors and sensitivity to mineralocorticoid treatment are stimulated in SHR, whereas high exogenous mineralocorticoid levels circulate in DOCA-treated rats. Thus, in addition to the deleterious effects of hypertension, endocrine factors may contribute to the abnormalities of hippocampus in SHR and DOCA-treated rats.