抄録
The present experiment was performed to investigate the interactive effects of different prior photoperiods and stress on testicular weight in Syrian hamsters under the neutral photoperiod. Seasonality was experimentally manipulated by the change of photoperiod. One group was exposed to LD 12.5 : 11.5 for 12 weeks following 8-week long photoperiod (LP)exposure. The other group was exposed to the same neutral photoperiod for 12 weeks after 8-week short photoperiod(SP). Stress was produced by food deprivation of fixed days or random days throughout the 12 weeks of the neutral photoperiod. The results clearly showed that unpredictable food deprivation on 25% days throughout the 12-week testing period induced more detrimental effects on testes than predictable deprivation once every 4 days in the LP group. Stress tolerance associated with food deprivation was weaker for the animals transferred from LP than for the ones transferred from SP. This finding suggests that stress tolerance varies with season.
