| Objective:1. To study the effectiveness, mechanism of circadian rhythm on sleep pattern and energy metabolism of rats.2. To study the effectiveness, mechanism of the melatonin intervention on sleep pattern and energy metabolism changing in circadian rhythm-induced rats.Methods:1. To study the effectiveness of LD photoperiod conditions on the sleep pattern and energy metabolism of rats.1.1 To study the correlation between EEG and sleep high-throughput technique recorded sleep time of rats.SD Rats (n=12) were divided into EEG group and CLAMS group,6 rats in each group. In the L/D:12h/12h(LD) photoperiod conditions, EEG and sleep high-throughput technology were used (sleep time as evaluation index) to study the correlation between EEG and sleep high-throughput technique recorded sleep time of rats.1.2 To study the effectiveness of LD photoperiod conditions on the 24h sleep pattern and energy metabolism of rats.SD Rats (n=6) were used as research objects. In the LD photoperiod conditions, CLAMS was used (sleep time, rest-activity rhythm and sleep-wake rhythm as evaluation index) to study on the changes of the 24h sleep pattern of rats and to study on the changes of the 24h energy metabolism of rats (heat, food intake, body temperature, weight as evaluation index).2. To study the effectiveness of LL photoperiod conditions on the sleep pattern and energy metabolism of rats.2.1 To study the effectiveness of LL photoperiod conditions (continuou-sly 8d) on the sleep pattern of rats.SD rats (n=12) were divided into LD and LL groups,6 rats in each group. In the LD and LL:24h(LL) photoperiod conditions, CLAMS was used (sleep time, rest-activity rhythm and sleep-wake rhythm as evaluation index) to study on the changes of the sleep pattern of rats (continuously 8d).2.2 To study the effectiveness of LL photoperiod conditions (continuou-sly 8d) on the energy metabolism of rats.SD rats (n=12) were divided into LD and LL groups,6 rats in each group. In the LD and LL photoperiod conditions, CLAMS was used (heat, food intake, body temperature, weight as evaluation index) to study on the changes of the energy metabolism of rats (continuously 8d).2.3 To study the correlation of LL photoperiod conditions on the 24h sleep pattern and energy metabolism of rats.SD rats (n=12) were divided into LD and LL groups,6 rats in each group. In the LD and LL photoperiod conditions, CLAMS was used (sleep time, rest-activity rhythm, sleep-wake rhythm, heat, food intake, body temperature, weight as evaluation index) to study of LL photoperiod conditions on the 24h sleep pattern and energy metabolism correlation on the 7th day.3. To study the mechanism of LL photoperiod conditions on sleep pattern and energy metabolism of rats.3.1 To study the effectiveness of LL photoperiod conditions on the sleep-related endogenous substances in rat brain.SD Rats (n=20) were divided into LD day, LD night, LL day and LL night groups,5 rats in each group. In the LD and LL photoperiod conditions, ELISA was used (PGD2, IL-1, TNF-a, GHRH, ROS, oleamide, etc.,17 kinds of sleep-related endogenous substances in the brain as evaluation index) to study brain sleep-related endogenous substances changing at daytime and nighttime on the 7th day.3.2 To study the effectiveness of LL photoperiod conditions on c-Fos expression in the DMH regions of rat brain.SD Rats (n=20) were divided into LD day, LD night, LL day and LL night groups,5 rats in each group. In the LD and LL photoperiod conditions, IHC was used (c-Fos expression of DMH regions) to study the changes of c-Fos expression at daytime and nighttime in DMH regions of rat brain on the 7th day.4. To study the effectiveness, mechanism of the melatonin intervention on the sleep pattern and energy metabolism in LL photoperiod conditions induced rats.4.1 To study the effectiveness of melatonin intervention on the changes of the sleep pattern and energy metabolism in LL photoperiod conditions induced rats.SD Rats (n=24) were divided into LD, LL, MT and NS groups,6 rats in each group. MT group were received 30 mg/kg melatonin orally by gavage for 7 days, and same volume as the NS group. In the LD and LL photoperiod conditions, CLAMS was used (sleep time, rest-activity rhythm, sleep-wake rhythm, heat, food intake, body temperature, weight as evaluation index) to study the effectiveness of melatonin intervention on the changes of sleep pattern and energy metabolism in LL photoperiod conditions induced rats.4.2 To study the effectiveness of melatonin intervention on the sleep-related endogenous substances in brain in LL photoperiod conditions induced rats.SD Rats (n=40) were divided into LD day, LD night, LL day, LL night, MT day, MT night, NS day and NS night groups,5 rats in each group. MT day and night groups were received 30 mg/kg melatonin orally by gavage for 7 days, and same volume as the NS day and night groups. In the LD and LL photoperiod conditions, ELISA was used (PGD2, IL-1, TNF-α, GHRH, ROS, oleamide, etc.,17 kinds of sleep-related endogenous substances in the brain as evaluation index) to study brain sleep-related endogenous substances changing at daytime and nighttime in LL photoperiod conditions induced rats.4.3 To study the effectiveness of melatonin intervention on c-Fos expression in the DMH regions of brain in LL photoperiod conditions induced rats.SD Rats (n=40) were divided into LD day, LD night, LL day, LL night, MT day, MT night, NS day and NS night groups,5 rats in each group. MT day and night groups were received 30 mg/kg melatonin orally by gavage for 7 days, and same volume as the NS day and night groups. In the LD and LL photoperiod conditions, IHC was used to study on the changes of c-Fos expression at daytime and nighttime in DMH regions of rat brain in LL photoperiod conditions induced rats.Results:1. To study the effectiveness of LD photoperiod conditions on the sleep pattern and energy metabolism of rats.1.1 To study the correlation between EEG and sleep high-throughput technique recorded sleep time of rats.The results showed that, LD photoperiod conditions which was compared with EEG (setting activities threshold of CLAMS on 60s,90s and 120s). The sleep time of rats were significantly decreased (p<Q.01), in the setting activity threshold on 30s that there was no difference (P>0.05).1.2 To study the effectiveness of LD photoperiod conditions on the 24h sleep pattern and energy metabolism of rats.In the LD photoperiod conditions, the results showed that the aspect of sleep pattern, compared with the daytime, the night sleep of rats was decreased (p<0.01). Both rest-activity and sleep-wake rhythm showed circadian rhythm changing.In the aspect of energy metabolism, compared with the daytime, the night heat and food intake of rats were significantly increased (p<0.01), and the 24h heat rhythm of rats showed circadian rhythm changing.2. To study the effectiveness of LL photoperiod conditions on the sleep pattern and energy metabolism of rats.2.1 To study the effectiveness of LL photoperiod conditions (continuou-sly 8d) on the sleep pattern of rats.In the aspect of sleep time, the results showed that the same day was compared with LD group. There were remarkably significant difference on the day and night sleep time of LL group rats (p<0.05 and P<0.01 respectively), and there was no statistically difference on total sleep time (p>0.05).Compared with two neighboring groups, there were no difference on the day, night and total sleep time of LD group rats during 1-8d (p>0.05). The 3d sleep time of LL group rats was shorter than the day before during the daytime (p<0.05), and there were no statistically difference on the night and total sleep time during 1-8d (p>0.05).In the aspect of sleep rhythm, both the rest-activity and sleep-wake rhythm of LD group rats showed circadian rhythm changing and showed rhythm cycle stability. The rest-activity and sleep-wake rhythm of LL group rats showed rear, circadian rhythm degraded and rhythm cycle changing. This phenomenon was the most significant in the date seventh.2.2 To study the effectiveness of LL photoperiod conditions (continuou-sly 8d) on the energy metabolism of rats.The results showed that, there were remarkably significant difference on the day, night heat and food intake of LL group rats (p<0.05 and p<0.01 respectively), 1-4d and 7d,8d the day heat were increased (p<0.05 and P<0.01 respectively),3-8d body temperature were decreased (p<0.05), and there were no difference on the total food intake and weight during 118d (P>0.05) when compared to LD group in the same day.There were remarkably significant difference on the day, night heat and food intake of LD group rats (p<0.05 and p<0.01 respectively), and there were no different on total heat, food intake and body temperature and weight (P>0.05) when compare to two neighboring groups. Furthermore, there were remarkably significant difference on the day, night heat and food intake of LL group rats (p<0.05 and P<0.01 respectively), the 3d total heat was higher than the day before (p<0.05). There were no difference on the total food intake, body temperature and weight during 1-8d (P>0.05).2.3 To study the correlation of LL photoperiod conditions on the 24h sleep pattern and energy metabolism of rats.The results showed that the day sleep time of LL group rats was decreased, but heat, and food intake were increased (p<0.05 and p<0.01 respectively). The night sleep time and heat were increased, but food intake was decreased (p<0.05 and P<0.01 respectively). The total heat was increased, but body temperature was decreased (p<0.01). There were no different on the total sleep time, food intake and weight (p>0.05) when compared to LD group.In the rhythm aspect of the rest-activity, sleep-wake and heat of LL group rats showed rear, circadian rhythm degraded when compared to LD group.3. To study the mechanism of LL photoperiod conditions on sleep pattern and energy metabolism of rats.3.1 To study the effectiveness of LL photoperiod conditions on the sleep-related endogenous substances in rat brain.The results showed that during the daytime, the levels of oleamide and ROS in the brain of LL group rats were increased (p<0.05), but the levels of GSSG, DSIP and GC were decreased (P<0.05). In addition, during the nighttime, the levels of INS, oleamide and ROS in the brain were increased (P<0.05 and p<0.01 respectively), but the levels of GSSG, DSIP, CST and CCK were decreased (p<0.01) when compared to LD group.3.2 To study the effectiveness of LL photoperiod conditions on c-Fos expression in the DMH regions of rat brain.The results showed that the c-Fos expression in the brain DMH regions of LL group rats was increased during the daytime (P<0.01), but there was no difference on the c-Fos expression in the brain DMH regions during the nighttime (p>0.05) when compared to LD group.4. To study the effectiveness, mechanism of the melatonin intervention on the sleep pattern and energy metabolism in LL photoperiod conditions induced rats.4.1 To study the effectiveness of melatonin intervention on the changes of the sleep pattern and energy metabolism in LL photoperiod conditions induced ratsThe results showed that the day sleep time of LL group rats was decreased, but heat and food intake were increased (p<0.05 and p<0.01 respectively). The night sleep time and heat were increased, but food intake was decreased (p<0.05 and P<0.01 respectively). The total heat was increased, but the body temperature was decreased (p<0.01). There were no different on the total sleep time, food intake and weight (p>0.05) when compared to LD group.Compare to LL group, there were no difference on the day, night, total sleep time, heat, food intake, body temperature and weight of NS group rats (p>0.05).Compare to NS group, the day food intake of MT group rats was decreased (P<0.01). There were no difference on the day sleep and heat (P>0.05). The night sleep time was decreased, but heat and food intake were increased (P<0.05 and p<0.01 respectively). The total sleep time was decreased, but heat, weight and body temperature was increased (p<0.05 and p<0.01 respectively). There was no difference on the total food intake (p>0.05).In the rhythm aspects, compared with LD group, the rest-activity, sleep-wake and heat of LL group rats showed rear, circadian rhythm degraded.Compared with LL group, the characteristics of the rest-activity, sleep-wake rhythm and heat of NS group rats were similar to LL group.Compared with NS group, the rest-activity, sleep-wake rhythm and heat of MT group rats showed circadian rhythm changing.4.2 To study the effectiveness of melatonin intervention on the sleep related endogenous substances in brain in LL photoperiod conditions induced rats.The results showed that during the daytime the levels of oleamide and ROS in the brain of LL group rats were increased (p<0.05), but the levels of GSSG, DSIP and GC were decreased (p<0.05). In addition, during the nighttime, the levels of INS, oleamide and ROS in the brain were increased (p<0.05 and p<0.01 respectively), but the levels of GSSG, DSIP, CST and CCK were decreased (p<0.01) when compared to LD group.Compared with LL group, there were no difference on the sleep related endogenous substances in brain of NS group rats during the daytime and nighttime (P>0.05).Compared with NS group, the levels of PGD2, IL-1, GSSG, INS of MT group rats were increased (P<0.05 and p<0.01 respectively), but the levels of TNF-α, MDP, NO, NPS, ROS, oleamide, CST were decreased (P<0.05 and p<0.01 respectively) during the daytime. In addition, during the nighttime, the levels of MT, GHRH and GSSG were increased(p<0.05 and p<0.01 respectively), but the levels of TNF-a, IL-1, NPS, oleamide, DSIP, CST, INS, CCK were decreased (p<0.05 and P<0.01 respectively).4.3 To study the effectiveness of melatonin intervention on c-Fos expression in the DMH regions of brain in LL photoperiod conditions induced rats.The results showed that the c-Fos expression in the brain DMH regions of LL group rats was increased during the daytime (p<0.01), but there was no difference on the c-Fos expression in the brain DMH regions during the nighttime (p>0.05) when compared to LD group.Compared with LL group, there were no difference on the c-Fos expression in the brain DMH regions of NS group rats during the daytime and nighttime (P>0.05).Compared with NS group, the c-Fos expression in the brain DMH regions of MT group rats was decreased during the daytime (P<0.05), but there was no difference on the c-Fos expression in the brain DMH regions during the nighttime (P>0.05).Conclusion:1. Sleep pattern and energy metabolism of rats were affected by circadian rhythm, and sleep which was often associated with lower energy metabolism.2. Melatonin can effectively improve the changes of the sleep pattern and energy metabolism of rats which caused by circadian rhythm and improved sleep quality.3. Whether the change of photoperiod conditions or the melatonin intervention, the occurrence of the sleep rhythm adjusted with heat increased in the rats.4. The effectiveness, mechanism of circadian rhythm, melatonin intervention on sleep pattern and energy metabolism related to the brain DMH regions and participated various sleep related endogenous substances. |
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