PDF(Pubmed)
Abstract：
UNASSIGNED: Stress elicits physiological and neuroendocrine responses mediated by the hypothalamic-pituitary-adrenal (HPA) axis and lateral hypothalamus (LH). However, prolonged stress can dysregulate neuropeptide systems like orexin. This study investigated the effects of temporary and prolonged stress on HPA activity and orexin processing in the rat LH.
UNASSIGNED: Male Wistar rats were exposed to various stress repetitions. The stress paradigm is defined as short (acute; 1 day and mild; 3 days) and long (sub-chronic; 10 days and chronic; 21 days)-term 6 hr daily restraint stress. Plasma corticosterone (CORT) served as an index of HPA function. Expression of prepro-orexin and its processing enzymes prohormone convertases (PC) 1 and 2 was measured in LH tissues using semiquantitative RT-PCR.
UNASSIGNED: The plasma level of CORT was elevated following mild, sub-chronic, and chronic, but not acute stress versus unstressed controls. The expression of prepro-orexin was heightened following all stress exposures. However, PC1 increased and PC2 decreased only after prolonged stress. The PC1/PC2 ratio was also selectively augmented with sub-chronic and chronic stress, implying impaired orexin maturation.
UNASSIGNED: Together, these data demonstrate that the HPA axis and lateral hypothalamic orexin system respond to stress based on stress repetition. Changes in orexin processing enzyme mRNA, exclusively after chronic stress, imply potential effects on peptide maturation, requiring confirmation of the orexin production at the protein level.
UNASSIGNED: Male Wistar rats were exposed to various stress repetitions. The stress paradigm is defined as short (acute; 1 day and mild; 3 days) and long (sub-chronic; 10 days and chronic; 21 days)-term 6 hr daily restraint stress. Plasma corticosterone (CORT) served as an index of HPA function. Expression of prepro-orexin and its processing enzymes prohormone convertases (PC) 1 and 2 was measured in LH tissues using semiquantitative RT-PCR.
UNASSIGNED: The plasma level of CORT was elevated following mild, sub-chronic, and chronic, but not acute stress versus unstressed controls. The expression of prepro-orexin was heightened following all stress exposures. However, PC1 increased and PC2 decreased only after prolonged stress. The PC1/PC2 ratio was also selectively augmented with sub-chronic and chronic stress, implying impaired orexin maturation.
UNASSIGNED: Together, these data demonstrate that the HPA axis and lateral hypothalamic orexin system respond to stress based on stress repetition. Changes in orexin processing enzyme mRNA, exclusively after chronic stress, imply potential effects on peptide maturation, requiring confirmation of the orexin production at the protein level.
摘要：
■应激引起由下丘脑-垂体-肾上腺(HPA)轴和下丘脑外侧(LH)介导的生理和神经内分泌反应。然而,长时间的压力会失调神经肽系统，如食欲素。这项研究调查了暂时和长期应激对大鼠LH中HPA活性和食欲素处理的影响。
■雄性Wistar大鼠暴露于各种应激重复。压力范式定义为短期（急性；1天和轻度；3天）和长期（亚慢性；10天和慢性；21天）-6小时每日约束压力。血浆皮质酮（CORT）可作为HPA功能的指标。使用半定量RT-PCR在LH组织中测量了前食欲素及其加工酶前激素转化酶（PC）1和2的表达。
■轻度后，CORT的血浆水平升高，亚慢性，慢性，但不是急性压力与无压力控制。在所有压力暴露后，前食欲素的表达均升高。然而,仅在长时间应激后，PC1才增加，PC2才减少。PC1/PC2比率也选择性地增加亚慢性和慢性压力，暗示食欲素成熟受损。
■一起，这些数据表明，HPA轴和下丘脑外侧食欲素系统响应基于应激重复的应激。食欲素加工酶mRNA的变化，仅在慢性压力之后，暗示对肽成熟的潜在影响，需要在蛋白质水平上确认食欲素的产生。
■雄性Wistar大鼠暴露于各种应激重复。压力范式定义为短期（急性；1天和轻度；3天）和长期（亚慢性；10天和慢性；21天）-6小时每日约束压力。血浆皮质酮（CORT）可作为HPA功能的指标。使用半定量RT-PCR在LH组织中测量了前食欲素及其加工酶前激素转化酶（PC）1和2的表达。
■轻度后，CORT的血浆水平升高，亚慢性，慢性，但不是急性压力与无压力控制。在所有压力暴露后，前食欲素的表达均升高。然而,仅在长时间应激后，PC1才增加，PC2才减少。PC1/PC2比率也选择性地增加亚慢性和慢性压力，暗示食欲素成熟受损。
■一起，这些数据表明，HPA轴和下丘脑外侧食欲素系统响应基于应激重复的应激。食欲素加工酶mRNA的变化，仅在慢性压力之后，暗示对肽成熟的潜在影响，需要在蛋白质水平上确认食欲素的产生。
