Radahmadi Maryam, Izadi Mina Sadat, Rayatpour Atefeh, Ghasemi Maedeh
Department of Physiology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran.
Basic Clin Neurosci. 2021 Jan-Feb;12(1):133-148. doi: 10.32598/bcn.12.1.2346.1. Epub 2021 Jan 1.
Corticotropin-Releasing Hormone (CRH) is involved in stress and energy homeostasis. On the other hand, CRH receptors also exist within the paraventricular nucleus (PVN) and Central Amygdala (CeA) nuclei. The present study compared the effect of CRH microinjections into PVN and CeA on three consecutive hours and cumulative food intake, internal regulatory factors of food intake, such as serum leptin and ghrelin, as well as blood glucose levels in rats under different acute psychological (Social Stress [SS] and Isolation Stress [IS] group) stresses.
Sixty-six male Wistar rats were randomly allocated to 11 groups: Control, Sham, CRH-PVN, CRH-CeA, SS, IS, SS-CRH-PVN, SS-CRH-CeA, IS-CRH-PVN, and IS-CRH-CeA groups. The CRH (2 µg/kg in 0.5 µL saline) was injected into PVN and CeA nuclei in rats under everyday, acute social stress and isolation stress conditions.
Acute isolation and social stresses did not affect cumulative food intake. Whereas isolation stress led to changes in both leptin and glucose levels, social stress reduced only glucose levels. Cumulative food intake significantly decreased under acute CRH injection into the CeA and particularly into the PVN. Blood glucose significantly reduced in all the groups receiving CRH into their CeA.
The PVN played a more important role compared to CeA on food intake. These nuclei probably employ different mechanisms for their effects on food intake. Besides, it seems that exogenously CRH injection into the PVN probably had a more anorectic effect than naturally activated CRH by stresses. Acute isolation stress had a greater impact than social stress on leptin level and cumulative food intake. Thus, elevated food intake related to leptin compared to ghrelin and glucose levels in the CRH-PVN group under acute social stress.
促肾上腺皮质激素释放激素（CRH）参与应激和能量稳态。另一方面，CRH受体也存在于室旁核（PVN）和中央杏仁核（CeA）中。本研究比较了在不同急性心理应激（社会应激[SS]和隔离应激[IS]组）下，向大鼠PVN和CeA中连续三小时微量注射CRH对累积食物摄入量、食物摄入的内部调节因子（如血清瘦素和胃饥饿素）以及血糖水平的影响。
66只雄性Wistar大鼠随机分为11组：对照组、假手术组、CRH-PVN组、CRH-CeA组、SS组、IS组、SS-CRH-PVN组、SS-CRH-CeA组、IS-CRH-PVN组和IS-CRH-CeA组。在日常、急性社会应激和隔离应激条件下，将CRH（2μg/kg溶于0.5μL盐水中）注射到大鼠的PVN和CeA核中。
急性隔离应激和社会应激均不影响累积食物摄入量。虽然隔离应激导致瘦素和葡萄糖水平均发生变化，但社会应激仅降低了葡萄糖水平。急性向CeA尤其是PVN注射CRH后，累积食物摄入量显著降低。所有向CeA注射CRH的组中血糖均显著降低。
与CeA相比，PVN在食物摄入方面发挥着更重要的作用。这些核团可能通过不同机制影响食物摄入。此外，向PVN中注射外源性CRH可能比应激自然激活的CRH具有更强的厌食作用。急性隔离应激比社会应激对瘦素水平和累积食物摄入量的影响更大。因此，在急性社会应激下，CRH-PVN组中与瘦素相关的食物摄入量升高，高于胃饥饿素和葡萄糖水平。
