#SexHormones

#Biology

#EndocrineSystem

Introduction

• Sex hormones are steroid hormones that play a key role in reproductive and sexual health: 

  • Estrogen: Produced in the ovaries, estrogen is responsible for bone development and maintenance, and protects against atherosclerosis. 

  • Testosterone: Produced in the testes, testosterone is responsible for sperm production. 

  • Progesterone: Produced in the ovaries, adrenal glands, and placenta, progesterone helps stabilize menstrual cycles and prepares the body for pregnancy. 

• Steroid hormone, any of a group of hormones that belong to the class of chemical compounds known as steroids; they are secreted by three “steroid glands”—the adrenal cortex, testes, and ovaries—and during pregnancy by the placenta.

• All steroid hormones are derived from cholesterol.

• As a precursor, cholesterol is involved in the creation of fat-soluble hormones that are essential for several physiological processes in the body.

• Fat-soluble hormones are able to pass through cell membranes because they are hydrophobic and water-insoluble.

Estrogen

• Estrogen is a steroid hormone associated with the female reproductive organs and is responsible for developing female sexual characteristics.

• For instance, testosterone has a ketone group at the 3 position, while estradiol (a form of estrogen) has a hydroxyl group.

• The hydroxyl group on estrogen (e.g., estradiol) is crucial for its binding interactions with estrogen receptors (ERα and ERβ), aiding in the formation of hydrogen bonds.

• Function. The function of ER is to act as the second messenger of estrogen action by regulating gene expression in the nucleus.

Testosterone

• Testosterone is a hormone that plays a key role in the development and maintenance of male characteristics and overall health.

• The ketone group in testosterone is essential for its interaction with receptors in the body, allowing it to trigger various physiological effects like muscle growth, bone development, and the regulation of male secondary sexual characteristics.

Progesterone

• Progesterone is a sex hormone that supports menstruation and pregnancy. It also helps prepare the breasts for breastfeeding. In men and people with testes, progesterone helps make sperm and male hormones.

• Progesterone is a C21-steroid hormone with a pregnane skeleton; it has oxo substituents at positions 3 and 20 and is unsaturated at C(4)-C(5).

• Progesterone is known to act in an immunosuppressive manner, particularly during pregnancy. It promotes a Th-2 cytokine profile, which may contribute to a reduced immune response.

• The progesterone-induced mediator (PIBF) increases the production of Th2 cytokines, thereby enhancing the Th2 immune response.

• The oxygen atoms at positions 3 and 20 in progesterone facilitate the conversion of hydroxyl groups into keto groups, crucial for its interactions and functions within biological systems.