Aging, Aluminium and Basal Forebrain Lesions Modify Substrate Kinetics of Erythrocyte Membrane Na,K-ATPase in the Rat

Article type: Research Article

Authors: Jovičić, Milena Erić^{a; *} | Popović, Miroljub^b | Nešić, Katica Jovanova^a | Popović, Natalija^c | Pavlović, Svetlana Jovičić^d | Rakić, Ljubisav^e

Affiliations: [a] Institute of Virology, Vaccines and Sera Torlak, Vojvode Stepe 458, 11221 Belgrade, Serbia | [b] Departmento de Anatomía Humana y Psicobiología, Facultad de Medicina, Universidad de Murcia, Campus Universitario de Espinardo, 30100 Murcia, Spain | [c] Departamento de Fisiología Animal, Facultad de Biología, Universidad de Murcia, Campus Universitrario de Espinardo, 30100 Murcia, Spain | [d] Institute of Nephrology, Clinical Center of Serbia, Pasterova 2, Faculty of Medicine, 11000 Belgrade, Serbia | [e] Serbian Academy of Science and Art, Knez Mihajlova 35, 11001 Belgrade, Serbia

Correspondence: [*] Corresponding author: Milena Erić Jovičić, PhD, Institute of Virology, Vaccines and Sera Torlak, Vojvode Stepe 458, 11221 Belgrade, Serbia. Tel.: +381 11 3970 548; Fax: +381 11 2471 838; E-mail: ericjovicic@sbb.co.yu.

Abstract: Several studies suggested that the activity of erythrocyte Na,K-ATPase declines with aging. Here, it is postulated that alterations in the substrate kinetics of the erythrocyte membrane Na,K-ATPase could be more aggravated in conditions of brain cholinergic dysfunction seen in Alzheimer's disease than in normal aging. To test this hypothesis, we compared the Na,K-ATPase activity (Vmax/Km parameters) in aged rats with those in young rats with brain cholinergic dysfunction induced by electrolytic-, kainic acid-lesioned nucleus basalis magnocellularis (NBM) or by intracerebroventricular AlCl3 administration. In the above mentioned groups, Vmax values were significantly lower in comparison to the control animals. Furthermore, Km values were significantly higher in animals with electrolytic-induced NBM lesions, AlCl3 treated rats and aged animals. However, Km was significantly lower in kainic acid-induced NBM lesions compared to the control group. The Na,K-ATPase catalytic efficiency, estimated by the ratio Vm/Km, decreased as followed: young animals > aged animals > kainic acid lesion > electrolityc lesion > AlCl3. Our data suggest that neurodegenerative processes similar to those seen in Alzheimer's disease affect the sodium/potassium pump functionality which might be detected in peripheral blood erythrocyte membranes.

Keywords: Aging, aluminium, Alzheimer's disease, K-ATPase, Na, nucleus basalis magnocellularis, rats

DOI: 10.3233/JAD-2008-14108

Journal: Journal of Alzheimer's Disease, vol. 14, no. 1, pp. 85-93, 2008