Department of Animal Sciences, University of Illinois, Urbana-Champaign, Urbana, IL, USA.
Department of Animal and Food Sciences, Texas Tech University, Lubbock, TX, USA.
J Anim Sci. 2021 Aug 1;99(8). doi: 10.1093/jas/skab094.
Technologies that increase the efficiency and sustainability of food animal production to provide meat for a growing population are necessary and must be used in a manner consistent with good veterinary practices, approved labeled use, and environmental stewardship. Compounds that bind to beta-adrenergic receptors (β-AR), termed beta-adrenergic receptor ligands (β-ligands), are one such technology and have been in use globally for many years. Though all β-ligands share some similarities in structure and function, the significance of their structural and pharmacological differences is sometimes overlooked. Structural variations in these molecules can affect absorption, distribution, metabolism, and excretion as well as cause substantial differences in biological and metabolic effects. Several β-ligands are available for use specifically in cattle production. Ractopamine and zilpaterol are beta-adrenergic agonists approved to increase weight gain, feed efficiency, and carcass leanness in cattle. They both bind to and activate β1- and β2-AR. Lubabegron is a newly developed selective beta-adrenergic modulator with unique structural and functional features. Lubabegron displays antagonistic behavior at the β1- and β2-AR but agonistic behavior at the β3-AR. Lubabegron is approved for use in cattle to reduce ammonia emissions per unit of live or carcass weight. Additionally, lubabegron can withstand prolonged use as the β3-AR lacks structural features needed for desensitization. Due to these unique features of lubabegron, this new β-ligand provides an additional option in cattle production. The individual properties of each β-ligand should be considered when making risk management decisions, as unique properties result in varying human food safety profiles that can determine appropriate safe β-ligand use.
提高食品动物生产效率和可持续性以提供不断增长的人口所需肉类的技术是必要的，并且必须以符合良好兽医实践、批准的标签用途和环境管理的方式使用。与β-肾上腺素能受体（β-AR）结合的化合物，称为β-肾上腺素能受体配体（β-配体），就是这样一种技术，并且已经在全球范围内使用了多年。虽然所有的β-配体在结构和功能上都有一些相似之处，但它们结构和药理学差异的重要性有时被忽视。这些分子的结构变化会影响吸收、分布、代谢和排泄，并且会导致生物学和代谢效应的显著差异。有几种β-配体专门用于牛生产。莱克多巴胺和扎利培酮是批准用于增加牛体重增加、饲料效率和胴体瘦肉率的β-肾上腺素能激动剂。它们都与β1-和β2-AR 结合并激活β1-和β2-AR。Lubabegron 是一种新开发的具有独特结构和功能特征的选择性β-肾上腺素能调节剂。Lubabegron 在β1-和β2-AR 上表现出拮抗行为，但在β3-AR 上表现出激动行为。Lubabegron 被批准用于牛，以减少单位活体或胴体重的氨气排放。此外，由于β3-AR 缺乏脱敏所需的结构特征，lubabegron 可以耐受长时间使用。由于 lubabegron 的这些独特特征，这种新的β-配体为牛生产提供了另一种选择。在做出风险管理决策时，应考虑每种β-配体的个体特性，因为独特的特性会导致不同的人类食品安全状况，从而决定适当的安全β-配体使用。
