Steroid Hormones

Steroid Hormones

Definition: Steroid hormones are a class of hormones derived from cholesterol. They are lipid-soluble and can easily pass through cell membranes to bind to specific receptors inside target cells, influencing various physiological processes.

Types of Steroid Hormones

• Glucocorticoids:

• Example: Cortisol
• Function: Regulate metabolism, immune response, and stress response. They help increase blood glucose levels and reduce inflammation.

• Mineralocorticoids:

• Example: Aldosterone
• Function: Control electrolyte balance and blood pressure by promoting sodium retention and potassium excretion in the kidneys.

• Androgens:

• Example: Testosterone
• Function: Responsible for the development of male secondary sexual characteristics, sperm production, and influencing libido in both males and females.

• Estrogens:

• Example: Estradiol
• Function: Regulate female reproductive functions, menstrual cycle, and development of female secondary sexual characteristics.

• Progestogens:

• Example: Progesterone
• Function: Prepare the uterus for pregnancy and maintain the uterine lining during pregnancy.

Mechanism of Action

• Steroid hormones exert their effects by diffusing through the cell membrane and binding to specific intracellular receptors. This hormone-receptor complex then translocates to the nucleus, where it influences gene expression by acting on specific DNA sequences, leading to changes in protein synthesis.

Clinical Relevance

• Hormonal Imbalances: Abnormal levels of steroid hormones can lead to various health issues, such as Cushing’s syndrome (excess cortisol) or Addison’s disease (insufficient cortisol).
• Hormone Replacement Therapy (HRT): Synthetic steroid hormones are often used in HRT to alleviate symptoms associated with hormonal deficiencies, particularly during menopause.
• Performance Enhancement: Anabolic steroids (synthetic derivatives of testosterone) are sometimes misused for muscle growth and athletic performance enhancement, leading to potential health risks.

Conclusion

Steroid hormones play vital roles in regulating numerous physiological processes, including metabolism, immune function, reproduction, and stress response. Understanding their functions and mechanisms is essential for diagnosing and treating related disorders.

References

1. Funder JW. “Mineralocorticoid action.” Endocrinology. 2017; 158(11): 3709-3717. DOI: 10.1210/en.2017-01341
2. Chrousos GP. “Stress and disorders of the stress system.” Nature Reviews Endocrinology. 2009; 5(7): 374-381. DOI: 10.1038/nrendo.2009.93
3. Nieman LK. “Cushing’s syndrome: a review.” Journal of Clinical Endocrinology & Metabolism. 2015; 100(8): 2841-2850. DOI: 10.1210/jc.2015-1850