Globin proteins exist in every cell type of the vasculature, from erythrocytes to endothelial cells, vascular smooth muscle cells, and peripheral nerve cells. Many globin subtypes are also expressed in muscle tissues (including cardiac and skeletal muscle), in other organ-specific cell types, and in cells of the central nervous system. The ability of each of these globins to interact with molecular oxygen (O₂) and nitric oxide (NO) is preserved across these contexts. Endothelial α-globin is an example of extra-erythrocytic globin expression. Other globins, including myoglobin, cytoglobin, and neuroglobin are observed in other vascular tissues. Myoglobin is observed primarily in skeletal muscle and smooth muscle cells surrounding the aorta or other large arteries. Cytoglobin is found in vascular smooth muscle but can also be expressed in non-vascular cell types, especially in oxidative stress conditions after ischemic insult. Neuroglobin was first observed in neuronal cells, and its expression appears to be restricted mainly to the central and peripheral nervous systems. Brain and central nervous system neurons expressing neuroglobin are positioned close to many arteries within the brain parenchyma and can control smooth muscle contraction and, thus, tissue perfusion and vascular reactivity. Overall, reactions between NO and globin heme-iron contribute to vascular homeostasis by regulating vasodilatory NO signals and scaveging reactive species in cells of the mammalian vascular system. Here, we discuss how globin proteins affect vascular physiology with a focus on NO biology, and offer perspectives for future study of these functions.

中文翻译：

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珠蛋白在心血管生理学中的作用

球蛋白存在于脉管系统的每种细胞类型中，从红细胞到内皮细胞、血管平滑肌细胞和周围神经细胞。许多珠蛋白亚型也在肌肉组织（包括心肌和骨骼肌）、其他器官特异性细胞类型和中枢神经系统细胞中表达。这些珠蛋白中的每一个与分子氧（O ₂) 和一氧化氮 (NO) 在这些环境中得以保留。内皮 α-珠蛋白是红细胞外珠蛋白表达的一个例子。在其他维管组织中观察到其他珠蛋白，包括肌红蛋白、细胞红蛋白和神经红蛋白。肌红蛋白主要存在于主动脉或其他大动脉周围的骨骼肌和平滑肌细胞中。细胞红蛋白存在于血管平滑肌中，但也可以在非血管细胞类型中表达，尤其是在缺血性损伤后的氧化应激条件下。神经球蛋白最初是在神经元细胞中观察到的，其表达似乎主要局限于中枢和周围神经系统。表达神经球蛋白的大脑和中枢神经系统神经元位于大脑实质内的许多动脉附近，可以控制平滑肌收缩，因此，组织灌注和血管反应性。总的来说，NO 和珠蛋白血红素铁之间的反应通过调节血管扩张性 NO 信号和清除哺乳动物血管系统细胞中的活性物质来促进血管稳态。在这里，我们讨论珠蛋白如何影响血管生理学，重点是 NO 生物学，并为未来研究这些功能提供观点。