Mechanisms of Circadian Blood Pressure and Activity Rhythms

昼夜血压和活动节律的机制

• 批准号: 8349777
• 负责人: Jurgen Schnermann
• 金额: $ 19.84万
• 依托单位: NATIONAL INSTITUTE OF DIABETES AND DIGESTIVE AND KIDNEY DISEASES
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/8349777
• 关键词: Animals; Behavior; Behavioral; Biological Clocks; Blood Pressure; Body Temperature; Body Weight; Cardiac; Circadian Rhythms; Complex; Coupling; Cues; Defect; Diabetic Nephropathy; Disease; Dissociation; Eating; Energy Supply; Failure; Food; Genes; Goals; Heart Rate; Hour; Human; Hypertension; Length; Metabolic; Methods; Motor Activity; Mus; Neurons; Output; Pattern; Peripheral; Phase; Process; Regimen; Running; Time; Variant; attenuation; cardiovascular risk factor; diabetic; falls; feeding; food restriction; improved; peripheral blood; response

1. Circadian rhythms of blood pressure, heart rate, and core body temperature have been shown to be strongly entrained by food intake such that feeding restricted to 4 hours during daytime (from 10 AM to 2 PM) was associated with a prompt shift of peak values in all three variables from the dark period to the daytime. Surprisingly however, daytime restricted feeding had little effect on voluntary locomotor activity as assessed by running wheel activity, the most commonly used method to determine circadian rhythmic patterns. Peaks of running wheel activity during 6 days of daytime restricted feeding continued to occur with onset of the dark period with a small second activity around the time of feeding. Peak night time activity was seen in the first half of the dark period and this activity fell slightly with the duration of daytime feeding. Nevertheless, the dissociation in the entrainment of cardiac and metabolic variables on the one hand and voluntary running activity on the other suggests a complex interaction between clock gene outputs and behavioral adjustments. 2. Determination of food intake during daytime restricted feeding showed that the 4 hour feeding regimen used in our studies is associated with a sub-caloric energy supply. Body weight over a 6 day period fell from 27.4 to 25 g and food intake was about 20% less than during ad libitum feeding. This energy deficit was even more pronounced in diabetic Akita mice in which body weight fell from 23.4 to 19.4 over 6 days, and this was associated with dramatic reductions of core body temperatures during the dark phase. Stable body weights and higher food intakes were found when the food restriction was extended from 4 to 6 hours (from 9 AM to 3 PM). Extended feeding during the daytime markedly reduced the fall in body temperature in the night time observed during restricted feeding in wild type and diabetic animals suggesting that in addition to food-dependent entrainment of daily rhythms caloric energy supply determines the magnitude of the rhythmic perturbations.

1。昼夜节律的血压，心率和核心体温的节奏已被证明是被食物摄入强烈累及的，因此在白天（从上午10点到下午10点）喂食限制为4小时，与从黑暗时期到白天的所有三个变量中的峰值迅速转移。然而，令人惊讶的是，通过运行车轮活动评估的自愿运动活动的影响很小，这是确定昼夜节律节奏模式的最常用方法。随着黑暗时期的发作，日6天限制喂养的跑步轮活动的峰值继续发生，喂食时间左右的第二个活动。在黑暗时期的上半场看到了高峰夜间活动，随着白天喂养的持续时间，这项活动略有下降。然而，一方面，心脏和代谢变量夹带的分离以及另一方面的自愿跑步活动表明时钟基因输出与行为调整之间存在复杂的相互作用。 2。在日间限制喂养中的食物摄入量的确定表明，我们研究中使用的4小时喂养方案与亚平热能量供应有关。 6天的体重从27.4 g下降到25 g，食物摄入量比随意进食时少20％。这种能量不足在糖尿病性秋田小鼠中更为明显，其中体重在6天内从23.4下降到19.4，这与黑暗阶段期间核心体温的显着降低有关。当食物限制从4个小时（从上午9点到下午3点）时，发现体重稳定的体重和较高的食物摄入量。在白天进行的延长喂养显着降低了在野生型和糖尿病动物限制喂养过程中观察到的夜间体温下降，这表明除了食物依赖于每日节奏的热量热能供应外，还决定了节奏扰动的大小。