Department of Zoology, Savitribai Phule Pune University, Ganeshkhind, Pune 411 007, India; Department of Zoology, Bhavan's Hazarimal Somani College, Chowpatty, Mumbai 400 007, India.
Department of Zoology, Bhavan's Hazarimal Somani College, Chowpatty, Mumbai 400 007, India.
Neuropeptides. 2021 Aug;88:102152. doi: 10.1016/j.npep.2021.102152. Epub 2021 Apr 20.
Cocaine- and amphetamine-regulated transcript peptide (CART) is an anorexigenic neuropeptide known to play a key role in energy homeostasis across the vertebrate phyla. In the current study, we have investigated the response of the CART immunoreactive system to varying energy states in the brain of a tadpole model. The pro-metamorphic tadpoles of Euphlyctis cyanophlyctis were fasted, or intracranially injected with glucose or 2-deoxy-d-glucose (2DG; an antagonist to glucose inducing glucoprivation) and the response of the CART containing system in various neuroanatomical areas was studied using immunohistochemistry. Glucose administration increased the CART immunoreactivity in the entopeduncular neurons (EN), preoptic area (POA), ventral hypothalamus (vHy) and the Edinger Westphal nucleus (EW) while CART positive cells decrease in response to fasting and glucoprivation. A substantial decrease in CART was noted in the EW nucleus of tadpoles injected with 2DG. These regions might contain the glucose-sensing neurons and regulate food intake in anurans. Therefore, we speculate that the function of central CART and its antagonistic action with NPY in food and feeding circuitry of anurans is evolutionary conserved and might be responsible for glucose homeostasis.
可卡因和安非他命调节转录肽（CART）是一种厌食神经肽，已知在脊椎动物门中在能量平衡中发挥关键作用。在本研究中，我们研究了 CART 免疫反应系统对变应性状态下脑内不同能量状态的反应在 Euphlyctis cyanophlyctis 变态前的蝌蚪模型中。用葡萄糖或 2-脱氧-d-葡萄糖（2DG；葡萄糖诱导的葡萄糖剥夺的拮抗剂）对禁食或颅内注射的蝌蚪进行处理，并用免疫组织化学研究了各种神经解剖区域中包含 CART 的系统的反应。葡萄糖给药增加了中脑脚间核（EN）、视前区（POA）、腹侧下丘脑（vHy）和 Edinger-Westphal 核（EW）中 CART 的免疫反应性，而 CART 阳性细胞则因禁食和葡萄糖剥夺而减少。在注射 2DG 的蝌蚪的 EW 核中观察到 CART 大量减少。这些区域可能包含葡萄糖感应神经元，并调节无尾两栖动物的食物摄入。因此，我们推测中枢 CART 的功能及其与 NPY 在无尾两栖动物食物和进食回路中的拮抗作用是进化保守的，可能负责葡萄糖稳态。
