EFFECT OF TNFRP55 DEFICIENCY ON THE CIRCADIAN LOCOMOTOR ACTIVITY AND THE ESTROUS CYCLE IN MOUSE

ARIAS JL; RAGUSSA V; CASAIS M; DELGADO SM; DI GENARO MS; ANZULOVICH A.C.

Mendoza

Conferencia; XXVIII Reunión Científica Anual de la Soc. de Biología de Cuyo; 2010

Soc. Biol. de Cuyo

The master clock in the suprachiasmatic nucleus synchronizes peripheralclocks through diffusible signals and behavioural rest-activitycycles. However, such signals are not still completely elucidated.It is known that the TNF suppresses clock genes expression.Our objective was: to analyze the effect of TNFRp55 deficiency onthe clock-controlled rhythmic locomotor activity as well as on theday-night variation of the estrous cycle in C57BL/6 mice. Circadianlocomotor activity was registered during 20 days using theArchron system. Analysis and characterization of the estrous cycleswere performed on vaginal smears obtained during 12 days at ZT2(9h) and ZT14 (21h). The data were analysed by Mann-Whitneytest, significance p<0.05. We observed nocturnal activity decreasedand desynchronized in the TNRFp55-/- mice. Estrous cycles last6,0±0,6 vs 5,15±0,5 (p<0.03) days in wild type and TNRFp55-/-mice, respectively. TNF regulates the endogenous clock activityand the daily occurrence of the estrous cycle through its TNFRp55receptor.