Nitric oxide (NO) plays a crucial role in maintaining equilibrium within the endothelium, the inner lining of blood and lymphatic vessels. The entire circulatory system, from the heart to the tiniest capillaries, is lined with vascular endothelial cells. A reduction in NO production can disrupt this balance, leading to increased risks of conditions such as cardiovascular disease, hypertension, blood clotting, and inflammation.
Table of Contents
The production of NO is strongly influenced by various hormones, and in turn, NO is involved in regulating some hormone functions.
Aging signifies a decline in both hormones and nitric oxide, and this decline can impact various bodily functions.
Effects of aging on hormones and Nitric oxide production
Several hormones, including Estrogen, Testosterone, Progesterone, DHEA, Insulin, Growth Hormone, and Triiodothyronine (T3), positively influence endothelial Nitric Oxide Synthase (eNOS), essential for NO production. However, as part of the natural aging process, the production of these hormones decreases. Consequently, eNOS functionality diminishes, reaching only about 50% by the age of 40 and a mere 15% by the age of 60.
Integrated hormonal influence on eNOS
Sex hormones
NO regulates hormone release in the hypothalamic-pituitary axis. NO helps trigger the release of hormones essential for sexual function, such as luteinizing hormone (LH). Furthermore, Estrogen enhances NO production, but its decline with age affects eNOS function, leading to health problems like hypertension in women. Progesterone and Testosterone also play direct roles in modulating NO production.
Adrenal glands
The adrenal glands need adequate NO to function properly. The absence of NO affects the production of hormones like cortisol, leading to inhibited immune response and cardiovascular complications.
Pituitary gland
Growth Hormone and IGF1 are known to stimulate eNOS. Other hormones, such as oxytocin, play a role in sexual health by affecting NOS activity.
Metabolic system
NO’s role extends to regulating carbohydrate metabolism and insulin production. It acts as a central regulator in managing body composition and energy metabolism.
Polycystic Ovarian Syndrome
A complex condition linked to various diseases mediated by NO. Its effects include increased oxidative stress, decreased NO levels, and other related physiological disturbances.
Thyroid
NO deficiency in individuals with thyroid imbalance can lead to symptoms like cold extremities. NO plays a role in managing reactive oxygen species (ROS) production, essential for optimal thyroid function.
Circadian rhythm
A decrease in NO from aging is associated with a disturbed circadian rhythm, contributing to conditions like hypertension, which increases the risk of cardiovascular disease.
By middle age, the human body’s ability to produce NO through the arginine/NOS pathway is significantly reduced. Understanding and addressing the complex relationship between hormones and NO is vital for preventing age-related diseases. Strategies to support the NO pathway may facilitate optimal production, enhancing overall well-being and possibly averting several health complications linked to aging. This comprehensive understanding of the role of NO in various biological functions could be a significant reference or trigger further discussions about necessary interventions to maintain NO levels and bolster cardiovascular health.
References
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- McNeill, Anne Marie, and Chunying Zhang. “Estrogen Increases Endothelial Nitric Oxide Synthase via Estrogen …” Stroke, 1 June 2002, www.ahajournals.org/doi/full/10.1161/01.STR.0000016325.54374.93.
- Ronchetti, Sonia A., et al. “Nitric Oxide Plays a Key Role in Ovariectomy-Induced Apoptosis in Anterior Pituitary: Interplay between Nitric Oxide Pathway and Estrogen.” PLOS ONE, Public Library of Science, 9 Sept. 2016, journals.plos.org/plosone/article?id=10.1371%2Fjournal.pone.0162455.
- Hodgin, Jeffrey B., et al. “Interactions between Endothelial Nitric Oxide Synthase and Sex Hormones in Vascular Protection in Mice.” The Journal of Clinical Investigation, American Society for Clinical Investigation, 15 Feb. 2002, www.jci.org/articles/view/14066.
