What is the Difference Between Aldosterone and Testosterone

The main difference between aldosterone and testosterone is that aldosterone is a hormone produced by the adrenal glands, whereas testosterone is a hormone produced by the testes in males and, to a lesser extent, in the ovaries in females.

Hormones are chemical messengers that are secreted directly into the blood. Several glands, organs, and tissues in the body produce hormones. In fact, studies have discovered over 50 hormones in the human body. Moreover, hormones and the glands that create and release them make up the endocrine system. Hormones control many different functions in the body, including sexual functions, reproduction, mood, growth and development, sleep-wake cycle, homeostasis, and metabolism. Aldosterone and testosterone are two of these hormones.

Key Areas Covered

1. What is Aldosterone 
     – Definition, Functions, Features
2. What is Testosterone
     – Definition, Functions, Features
3. Similarities Between Aldosterone and Testosterone
     – Outline of Common Features
4. Difference Between Aldosterone and Testosterone
     – Comparison of Key Differences

Key Terms

Aldosterone, Aldocorten, Aldocortin, Electrocortin, Hormones, Reichstein X, Testosterone

What is Aldosterone

Aldosterone is a mineralocorticoid steroid hormone. It is produced in the zona glomerulosa of the adrenal cortex. Some other names for aldosterone are aldocorten, aldocortin, electrocortin, or Reichstein X. The chemical formula of this molecule is C₂₁H₂₈O_5, and the molar mass is 360.450 g/mol. Aldosterone acts on the collecting duct and the late distal tube of the nephrons in the kidney. This hormone also plays a role in salt and water regulation in the body. It also aids in water and sodium reabsorption and potassium excretion and contributes to the acid-base balance. In addition, it has a smaller effect on the metabolism of proteins, carbohydrates, and fats. Furthermore, aldosterone is essential for sodium conservation in the kidney, salivary glands, colons, and sweat glands.

Figure 1: Biosynthetic Route from Cholesterol to Aldosterone

Functions of Aldosterone

The functions of aldosterone explained specifically are as follows.

• Aldosterone upregulates the sodium channels in the epithelial cells in the collecting duct and the colon. This increases the permeability of the apical membrane for sodium ions, hence increasing the absorption. To maintain the electrochemical balance of the system, the body reabsorbs Cl ions in conjunction with sodium ions.
• Aldosterone stimulates the secretion of potassium ions into the tubular lumen.
• Furthermore, aldosterone stimulates the secretion of H+ through the H+/ATPase in the intercalated cells of the cortical collecting tubules.

This hormone has the exact opposite function of the atrial natriuretic hormone that is secreted by the heart. Aldosterone is synthesized from corticosterone (which is a steroid derived from cholesterol). 

Moreover, an adult human produces about 20-200 micrograms of aldosterone. The renin-angiotensin system regulates the production of aldosterone. As a response to the variations in the plasma sodium and potassium levels and variation in blood pressure and volume, the kidney secretes renin. Renin also acts on angiotensinogen, which is a protein circulating in blood plasma. Renin cleaves this angiotensinogen into angiotensinogen I, which is then converted into angiotensinogen II, stimulating the adrenal glands to release aldosterone.

What is Testosterone

Testosterone is a steroid sex hormone. This hormone is present in males and in very minute quantities in females. The production of testosterone happens in the gonads (testicles and ovaries). Adrenal glands also produce the hormone DHEA, and the body later transforms it into testosterone and estrogen.

Testosterone is responsible for stimulating the development of male characteristics in the body. Testosterone levels are higher in males than in females. Moreover, testosterone exhibits different functions in different stages of life, which include the fetal development stage, puberty in male children, and adulthood.

Figure 2: Testosterone

During fetal development, testosterone triggers the development of the internal and external reproductive organs of males. Testosterone is responsible for the changes in males during the time of their puberty. Such changes that testosterone stimulates are an increase in the libido (the sex drive), enlargement of the prostate gland, penis, and testes, growth of pubic hair and body hair, and increase in height. Moreover, in adults, testosterone participates in the production of sperm, increases libido, ensures the strength of bones and muscles, and signaling of the body to produce new red blood cells.

Similarities Between Aldosterone and Testosterone

• Both aldosterone and testosterone are steroid hormones.
• They also play an important role in many body functions.

Difference Between Aldosterone and Testosterone

Definition

Aldosterone is a hormone produced by the adrenal glands, whereas testosterone is a hormone produced by the testes in males and, to a lesser extent, in the ovaries in females.

Functions

Aldosterone plays a role in salt and water regulation of the body, metabolism of proteins, carbohydrates, and fat, sodium conservation in the kidney, salivary glands, colons, and sweat glands, secretion of potassium ions into the tubular lumen, and secretion of H+ through the H+/ATPase in the intercalated cells of the cortical collecting tubules, while testosterone plays a role in the developmental changes that occur during the puberty of males, sperm production, increasing the libido, ensuring the strength of the bones and muscles, and signaling the body to produce new red blood cells.

Type of Hormones

While aldosterone is not a sex hormone, testosterone is a sex hormone.

Conclusion

Aldosterone and testosterone are two types of hormones. The main difference between aldosterone and testosterone is that aldosterone is a hormone produced by the adrenal glands, whereas testosterone is a hormone produced by the testes in males, and to a lesser extent, in the ovaries in females.

Reference:

1. “Aldosterone” Cleaveland Clinic.
2. “Testosterone.” Cleaveland Clinic.

Image Courtesy:

1. “From cholesterol to aldosterone” By Calvero – Own work (CC BY-SA 3.0) via Commons Wikimedia
2. “1-testosterone” By Xasodfuih – Own work (CC BY-SA 3.0) via Commons Wikimedia