Cortisol (CORT)

Cortisol (CORT)

Definition: Cortisol (CORT) is a steroid hormone produced by the adrenal glands, specifically in the zona fasciculata of the adrenal cortex. It plays a critical role in the body’s response to stress and helps regulate various physiological processes, including metabolism, immune response, and blood pressure.

Functions of Cortisol

• Metabolism Regulation:

• Cortisol influences carbohydrate metabolism by promoting gluconeogenesis, the process of converting non-carbohydrate substrates into glucose.
• It aids in fat metabolism by stimulating lipolysis, the breakdown of fats into fatty acids.

• Stress Response:

• Often referred to as the “stress hormone,” cortisol is released in response to stressors, helping prepare the body for a “fight or flight” response.
• It increases energy availability by mobilizing glucose and fatty acids.

• Immune System Modulation:

• Cortisol has anti-inflammatory properties and helps regulate immune responses. It can suppress the activity of immune cells and reduce inflammation.

• Blood Pressure Regulation:

• Cortisol helps maintain blood pressure by enhancing the sensitivity of blood vessels to catecholamines (e.g., adrenaline) and influencing fluid balance.

Regulation of Cortisol Secretion

• Circadian Rhythm: Cortisol levels typically follow a diurnal pattern, peaking in the early morning and declining throughout the day.
• Hypothalamic-Pituitary-Adrenal (HPA) Axis: The release of cortisol is regulated by the HPA axis; stress triggers the hypothalamus to release corticotropin-releasing hormone (CRH), stimulating the pituitary gland to secrete adrenocorticotropic hormone (ACTH), which in turn stimulates cortisol production in the adrenal glands.

Clinical Relevance

• Cushing’s Syndrome: A condition characterized by excessive cortisol production, leading to symptoms such as weight gain, hypertension, and glucose intolerance.
• Addison’s Disease: A disorder resulting from insufficient cortisol production, causing fatigue, low blood pressure, and darkening of the skin.
• Stress-Related Disorders: Chronic high levels of cortisol due to prolonged stress can contribute to various health issues, including anxiety, depression, and metabolic disorders.

Conclusion

Cortisol is an essential hormone involved in numerous physiological processes, particularly in response to stress. Understanding its functions and regulation is crucial for managing conditions related to hormonal imbalances.

References

1. Chrousos GP. “Stress and disorders of the stress system.” Nature Reviews Endocrinology. 2009; 5(7): 374-381. DOI: 10.1038/nrendo.2009.93
2. Nieman LK. “Cushing’s syndrome: a review.” Journal of Clinical Endocrinology & Metabolism. 2015; 100(8): 2841-2850. DOI: 10.1210/jc.2015-1850
3. Bornstein SR, et al. “Cortisol: A key regulator of metabolism.” Nature Reviews Endocrinology. 2019; 15(12): 747-761. DOI: 10.1038/s41574-019-0274-z