TEMPORAL PROFILES OF BIOMARKERS OF INFLAMMATION AND OXIDATIVE DAMAGE ARE MODIFIED BY AN INTRACEREBROVENTRICULAR INJECTION OF AΒ-AMYLOID (1-42) AGGREGATES IN ALZHEIMER 's DISEASE RAT MODEL

TORALES P,, ; IBANEZ J; RODRIGUEZ BRITO A,; SANCHEZ VELA M; MAYRA CORTEZ,; ALBA R; REBECA GOLINI; TOLEDO F; PELLERIN N; GARRAZA M; MARIA DELSOUC,; MARILINA CASAIS; DARIO C RAMIREZ; GOMEZ MEJIBA, SANDRA;; SILVIA DELGADO; ANA ANZULOVICH; LORENA NAVEGATORE-FONZO

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Congreso; SBC; 2024

006 - TEMPORAL PROFILES OF BIOMARKERS OF INFLAMMATION AND OXIDATIVE DAMAGE AREMODIFIED BY AN INTRACEREBROVENTRICULAR INJECTION OF AΒ-AMYLOID (1-42) AGGREGATESIN ALZHEIMER 's DISEASE RAT MODELTorales P, Ibanez J, Rodriguez Brito A, Sanchez Vela M, Cortez M, Alba R, Golini R, Toledo F, Pellerin N, Garraza M, Delsouc B, Casais M,Ramirez D, Gomez Mejiba S, Delgado S, Anzulovich A and Navigatore Fonzo LLaboratorio de Cronobiología, IMIBIO-SL, CONICET-UNSL. UNViMe E-mail: lorenavigfz@yahoo.com.ar.Alzheimer's disease (AD) is the major neurodegenerative cause of progressive dementia in the elderly. The accumulation of Aβ in the brain plays akey role in the pathogenesis of AD. Elevated levels of Aβ causes an increase in oxidative damage and exacerbates neuroinflammation. Besides cognitivedeficits, AD patients show alterations in their circadian rhythms. Previously, we found that an intracerebroventricular (i.c.v) injection of Aβ(1-42)modified the daily patterns of antioxidant enzyme activity in the rat temporal cortex. Taking into account these observations, the objective of this workwas to investigate the effects of an i.c.v. injection of Aβ(1–42) on 24 h patterns of biomarkers of inflammation and oxidative damage in the rat temporalcortex. Four-month-old male Holtzman rats were divided into two groups defined as: control (CO) and Aβ-injected (Aβ). Rats were maintained under12h-light:12 h-dark conditions and received water and food ad libitum. Tissues samples were isolated every 6 h during a 24 h period. Daily rhythms ofnitrites, iNOS, chlorotyrosine and nitrotyrosine levels were determined by ELISA. Statistical differences throughout the 24-h period were analyzed byone-way ANOVA, followed by a post-hoc test, to confirm statistical differences between ZTs within each group; chronobiological statistics were usedto confirm the presence of rhythm and Student t test to compare rhythm’s parameters (acrophase, mesor, and amplitude) between groups. We foundnitrites levels vary significantly and rhythmically throughout a day in the CO group, with rhythms’ acrophases occurring at the middle of the lightperiod. The nitrites rhythm’s acrophase was shifted at middle of the night and mesor was increased in the Aβ-injected animals (p