24-Hour changes in ACTH, corticosterone, growth hormone, and leptin levels in young male rats subjected to calorie restriction
24-Hour changes in ACTH, corticosterone, growth hormone, and leptin levels in young male rats subjected to calorie restriction
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DOI：
10.1081/cbi-200053522
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发表时间：
2005-01-01
影响因子：
2.8
通讯作者：
Alvarez, MP
中科院分区：
文献类型：
--
作者：
Chacón, F;Esquifino, AI;Alvarez, MP
限制年轻雄性大鼠的热量会增加血浆催乳素，降低黄体生成素（LH）和睾酮，并扰乱它们24小时的分泌模式。为了研究这是否可能是应激的结果，我们检测了24小时血浆促肾上腺皮质激素（ACTH）皮质酮、生长激素（GH）、瘦素和肾上腺皮质酮的变化。从大鼠出生第35天开始，在4周内对其进行热量限制，相当于正常摄入量的66%。对照组被关在单独的笼子里，按正常的卡路里摄入方案进食。在热量限制的大鼠中检测到明显较低的ACTH水平。在每日周期的光照阶段，限制热量的大鼠血浆皮质酮水平明显较高。血浆ACTH和皮质酮水平在一天中的时间变化仅在热量限制大鼠中具有显著性，在静息期结束时达到最大值。肾上腺皮质酮的日变化规律反映了循环皮质酮的日变化规律；然而，卡路里限制降低了其水平。血浆ACTH和皮质酮仅在对照组中有显著相关性。热量限制降低了血浆生长激素和瘦素，并扭曲了24小时节律。在第二项研究中，在每日周期的光照阶段，测量了组笼大鼠、隔离对照大鼠和卡路里限制大鼠的血浆ACTH和皮质酮水平。热量限制大鼠的血浆ACTH较低，血浆皮质酮较高，与隔离或组笼对照组相比。本文报道的激素分泌模式的变化可能是神经内分泌和代谢机制的一部分，这些机制是为了在食物短缺期间最大限度地生存而进化的。
Calorie restriction of young male rats increases plasma prolactin, decreases luteinizing hormone (LH) and testosterone, and disrupts their 24 h secretory pattern. To study whether this could be the consequence of stress, we examined the 24 h variations of plasma adrenocorticotropic hormone (ACTH) corticosterone, growth hormone (GH), leptin, and adrenal corticosterone. Rats were submitted to a calorie restriction equivalent to a 66% of usual intake for 4 weeks, starting on day 35 of life. Controls were kept in individual cages and allowed to cat a normal calorie regimen. Significantly lower ACTH levels were detected in calorie-restricted rats. Plasma corticosterone levels during the light phase of the daily cycle were significantly higher in calorie-restricted rats. Time-of-day variation in plasma ACTH and corticosterone levels attained significance in calorie-restricted rats only, with a maximum toward the end of the resting phase. The daily pattern of adrenal gland corticosterone mirrored that of circulating corticosterone; however, calorie restriction reduced its levels. Plasma ACTH and corticosterone correlated significantly in controls only. Calorie restriction decreased plasma GH and leptin, and it distorted 24h rhythmicity. In a second study, plasma ACTH and corticosterone levels were measured in group-caged rats, isolated control rats, and calorie-restricted rats during the light phase of the daily cycle. Plasma ACTH of calorie-restricted rats was lower, and plasma corticosterone was higher, compared with isolated or group-caged controls. The changes in the secretory pattern of hormones hereby reported may be part of the neuroendocrine and metabolic mechanisms evolved to maximize survival during periods of food shortage.