Ogino Madoka, Okumura Aki, Khan Md Sakirul Islam, Cline Mark A, Tachibana Tetsuya
Department of Agrobiological Science, Faculty of Agriculture, Ehime University, Matsuyama 790-8566, Japan.
Department of Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, 24061 Blacksburg, VA, United States.
Physiol Behav. 2014 Feb 10;125:57-61. doi: 10.1016/j.physbeh.2013.11.006. Epub 2013 Nov 27.
Corticotrophin-releasing hormone (CRH) plays an important role in response to stress, and exerts a physiological effect via its receptor, CRH receptor type-1 (CRH-R1) and CRH receptor type-2 (CRH-R2) with high affinity to CRH-R1 in mammals. Urocortin-3 (UCN-3), a CRH family peptide, is an endogenous ligand for CRH-R2 in mammals. The physiological roles of UCN-3 and CRH-R2 have been investigated in mammals, although their roles still need to be clarified in chicks (Gallus gallus). Few studies have been performed comparing the physiological responses of CRH and UCN-3 in chicks. Therefore the present study was conducted to investigate the effect of intracerebroventricular (ICV) injection of UCN-3 on food intake, rectal temperature, crop-emptying rate and behaviors in chicks, and to compare these physiological responses with the effects resulting from CRH injection. The ICV injection of 20 and 80 pmol UCN-3 decreased food intake, increased rectal temperature and decreased crop-emptying rate and the results were similar to those achieved with CRH. The injection of both UCN-3 and CRH increased spontaneous activity but the behavioral patterns were different: CRH increased the number of vocalizations while UCN-3 increased the number of jumps, wing-flaps and scratching behaviors. These results suggest that UCN-3 regulates food intake, body temperature, and gastric emptying via the CRH-R2 in the brain of chicks, and these effects were similar to those induced by CRH.
促肾上腺皮质激素释放激素（CRH）在应激反应中起重要作用，并通过其受体发挥生理效应，在哺乳动物中，1型促肾上腺皮质激素释放激素受体（CRH-R1）和2型促肾上腺皮质激素释放激素受体（CRH-R2）对CRH具有高亲和力。尿皮质素-3（UCN-3）是一种CRH家族肽，是哺乳动物中CRH-R2的内源性配体。尽管UCN-3和CRH-R2在雏鸡（家鸡）中的作用仍有待阐明，但已在哺乳动物中对它们的生理作用进行了研究。很少有研究比较雏鸡中CRH和UCN-3的生理反应。因此，本研究旨在探讨脑室内（ICV）注射UCN-3对雏鸡采食量、直肠温度、嗉囊排空率和行为的影响，并将这些生理反应与注射CRH所产生的影响进行比较。脑室内注射20和80 pmol UCN-3可降低采食量、升高直肠温度并降低嗉囊排空率，结果与注射CRH相似。注射UCN-3和CRH均增加了自发活动，但行为模式不同：CRH增加了鸣叫次数，而UCN-3增加了跳跃、振翅和抓挠行为的次数。这些结果表明，UCN-3通过雏鸡脑中的CRH-R2调节采食量、体温和胃排空，且这些作用与CRH诱导的作用相似。
