Estradiol reverts the decreased expression of BDNF (Brain derived neurotrophic factor) in the hippocampus of hypertensive rat models?

PIETRANERA L; SARAVIA F; GONZALEZ DENISELLE MC; ROIG P; DE NICOLA A. F.

Seefeld, Tyrol, Austria

Simposio; 18th International Symposium of the Journal of Steroid Biochemistry and Molecular Biology; 2008

Journal of Steroid Biochemistry and Molecular Biology.

ESTRADIOL REVERTS THE DECREASED EXPRESSION OF BDNF (BRAIN DERIVED NEUROTROPHIC FACTOR) IN THE HIPPOCAMPUS OF HYPERTENSIVE RATS MODELS L. Pietranera, F.E. Saravia, M.C. Gonzalez Deniselle, P. Roig, A.F. De Nicola Institute of Biology and Experimental Medicine, CONICET. Argentina Department of Human Biochemistry. Faculty of Medicine, UBA. Argentina   Hippocampal neuropathology is a recognized feature of the spontaneously hypertensive rat (SHR). In previous studies we found that DOCA-salt hypertensive rats and SHR present abnormalities in the hippocampus consisting of decreased cell proliferation in the dentate gyrus (DG), astroglial reactivity and decreased neuronal density in the hilus of the DG. These abnormalities are reversed by estradiol, an active neuroprotective agent, in both models of hypertension. In this work we studied if the hippocampal expression of BDNF is also altered during hypertension and whether estradiol treatment can reverse this abnormality. We used male SHR (BP» 190 mm Hg) and their normotensive Wistar Kyoto (WKY) controls; and DOCA-salt rats (BP» 160 mm Hg) and normotensive controls. Half of the animals in each model received a 14mg estradiol benzoate pellet during 2 weeks. BDNF mRNA expression was determined by in situ hybridization using an oligoprobe labeled with 35S-dATP. Optical density was quantified in autoradiographic films in CA1, CA3 and DG fields of the hippocampus. In both models, hypertensive animals showed decreased expression of BDNF mRNA in DG whereas estradiol treatment restored mRNA levels. Therefore, glial and neuronal changes of SHR and DOCA-salt rats are accompanied by a decreased expression of BDNF, a trophic factor necessary for neurogenesis and neural function. Full elucidation of estradiol effects may prove beneficial to developing novel therapeutic strategies for the encephalopathy of hypertension.