Comesaña Sara, Pérez-Tierra Gabriel, Calo Jessica, Velasco Cristina, Conde-Sieira Marta, Soengas José L
Centro de Investigación Mariña, Laboratorio de Fisioloxía Animal, Departamento de Bioloxía Funcional e Ciencias da Saúde, Facultade de Bioloxía, Universidade de Vigo, Vigo, Spain.
Am J Physiol Endocrinol Metab. 2025 Aug 1;329(2):E314-E323. doi: 10.1152/ajpendo.00066.2025. Epub 2025 Jul 12.
We aimed to evaluate the role of central leucine administration in the modulation of peripheral energy metabolism in fish. For this, rainbow trout () were administered via intracerebroventricular 1 μL·100 g body mass of saline solution alone (Control) or containing 10 μg·μL of leucine. Samples of plasma, liver, adipose tissue, white muscle, and red muscle were collected 1- and 3-h postinjection. Firstly, metabolite levels were assessed in plasma and liver and a decrease in liver triglyceride at 1 h and an increase in plasma fatty acid at 3 h were observed. Metabolites levels were also assessed in white muscle, revealing decreased levels of α-amino acids and glycogen at 1 h. In addition, liver enzymatic activity and mRNA levels related to glucose, fatty acid, and amino acid metabolism showed no relevant changes. Then, energy metabolism in adipose tissue and muscle was assessed by examining the mRNA abundance of genes related to metabolism and oxidative capacity, thermogenesis, mitochondrial dynamics (mitochondrial fusion and fission), and other metabolic regulatory factors. Mitochondrial fusion was significantly influenced at 1-h postinjection in white muscle (upregulation of , , , and ) and to a lesser extent in red muscle (upregulation of ). These findings differ from studies in mammals with leucine and in fish with other nutrients, in which liver metabolism is modulated. This also highlights the importance of leucine and its relationship with muscle and mitochondrial dynamics in controlling energy homeostasis in fish. We studied how central leucine administration affects peripheral energy metabolism in rainbow trout. No significant changes were found in liver metabolism, differing from mammalian comparable studies and from changes in hypothalamic energy status elicited by other nutrients in fish. Mitochondrial fusion was notably influenced in white muscle and to a lesser extent in red muscle. These findings highlight the unique role of leucine in the maintenance of energy homeostasis in fish.
我们旨在评估向鱼类中枢注射亮氨酸在调节外周能量代谢中的作用。为此，对虹鳟鱼通过脑室内注射，每100克体重注射1微升仅含生理盐水的溶液（对照组）或含10微克/微升亮氨酸的溶液。在注射后1小时和3小时收集血浆、肝脏、脂肪组织、白肌和红肌的样本。首先，评估血浆和肝脏中的代谢物水平，观察到1小时时肝脏甘油三酯减少，3小时时血浆脂肪酸增加。还评估了白肌中的代谢物水平，发现1小时时α-氨基酸和糖原水平降低。此外，与葡萄糖、脂肪酸和氨基酸代谢相关的肝脏酶活性和mRNA水平未显示出相关变化。然后，通过检查与代谢、氧化能力、产热、线粒体动力学（线粒体融合和裂变）以及其他代谢调节因子相关的基因的mRNA丰度，评估脂肪组织和肌肉中的能量代谢。注射后1小时，白肌中的线粒体融合受到显著影响（、、和上调），红肌中的影响较小（上调）。这些发现与哺乳动物中亮氨酸的研究以及鱼类中其他营养素的研究不同，在那些研究中肝脏代谢受到调节。这也突出了亮氨酸在控制鱼类能量稳态中与肌肉和线粒体动力学的关系及其重要性。我们研究了向虹鳟鱼中枢注射亮氨酸如何影响外周能量代谢。肝脏代谢未发现显著变化，这与哺乳动物的类似研究以及鱼类中其他营养素引起的下丘脑能量状态变化不同。线粒体融合在白肌中受到显著影响，在红肌中的影响较小。这些发现突出了亮氨酸在维持鱼类能量稳态中的独特作用。
