Pang Baoxing, Qi Xingyun, Zhang Huiliang
Department of Medical Genetics and Molecular Biochemistry, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA.
Department of Biology, Rutgers University, Camden, NJ 08103, USA.
Biomolecules. 2025 Mar 19;15(3):439. doi: 10.3390/biom15030439.
Cardiovascular diseases (CVDs), which include multiple disorders of the heart and blood vessels, are the leading causes of death. Nitric oxide (NO) is a vasodilator that regulates vascular tension. Endogenous NO is produced via the L-arginine-nitric oxide synthase (NOS) pathway. In conditions of cardiovascular dysfunction, NOS activity is impaired, leading to NO deficiency. In turn, the reduction in NO bioactivity exacerbates the pathogenesis of CVDs. Exogenous intake of inorganic nitrate supplements endogenous production via the nitrate-nitrite-NO pathway to maintain the NO supply. Salivary glands play an essential role in the conversion of nitrate to NO, with approximately 25% of circulating nitrate being absorbed and secreted into saliva. As a result, salivary nitrate concentrations can exceed that in the blood by more than tenfold. This recycled nitrate in saliva serves as a reservoir for NO and performs NO-like functions when endogenous NO production is insufficient. In this review, we summarize the emerging benefits of dietary nitrate in CVDs, with a particular focus on salivary-gland-mediated nitrate recirculation in maintaining NO bioavailability and cardiovascular homeostasis. Salivary-gland-mediated nitrate recirculation provides a novel perspective for potential intervention of CVDs.
心血管疾病（CVDs）包括心脏和血管的多种病症，是主要的死亡原因。一氧化氮（NO）是一种调节血管张力的血管扩张剂。内源性NO通过L-精氨酸-一氧化氮合酶（NOS）途径产生。在心血管功能障碍的情况下，NOS活性受损，导致NO缺乏。反过来，NO生物活性的降低会加剧CVDs的发病机制。外源性摄入无机硝酸盐通过硝酸盐-亚硝酸盐-NO途径补充内源性生成，以维持NO供应。唾液腺在硝酸盐转化为NO的过程中起着至关重要的作用，约25%循环中的硝酸盐被吸收并分泌到唾液中。因此，唾液中的硝酸盐浓度可能超过血液中的浓度十倍以上。唾液中这种循环利用的硝酸盐充当NO的储存库，并在内源性NO生成不足时发挥类似NO的功能。在这篇综述中，我们总结了膳食硝酸盐在CVDs中的新益处，特别关注唾液腺介导的硝酸盐再循环在维持NO生物利用度和心血管稳态方面的作用。唾液腺介导的硝酸盐再循环为CVDs的潜在干预提供了新的视角。
