Circadian variation in cerebral spermine and spermidine concentrations in entrained and free-running mice

Abstract

Abstract In the present study, although some evidence in favour of a circadian variation in brain spermidine concentration was obtained in Swiss mice, peak concentrations occurred during darkness and were therefore out of phase with those reported in a previous study in the same mouse strain (Rodichok and Friedman, 1978). In addition the largest magnitudes of oscillation (34.8 and 22.7% for spermidine and spermine, respectively) were only about one quarter as large as those previously reported. The changes in polyamines did not correlate with change in locomotor activity. In C.D. mice a more complex pattern of change in spermidine was observed with peaks occurring in both the light and the dark phases of the cycle. Exposure of these animals to continuous light or continuous darkness modified the pattern of these fluctuations but did not abolish them. It is concluded that, although daily fluctuations in spermidine and spermine concentration do occur in both entrained and free running mice such changes do not correlate with the phase of the light-dark cycle or with locomotor activity.