What type of hormones usually act through intracellular receptors?

Hydrophobic hormones typically act through intracellular receptors due to their chemical nature. These hormones, which include steroid hormones and thyroid hormones, can easily diffuse across the lipid bilayer of cell membranes because they are nonpolar. Once inside the cell, they bind to specific intracellular receptors located in the cytoplasm or nucleus.

This binding initiates a series of events that lead to changes in gene expression and protein synthesis, ultimately influencing various physiological processes. The ability of hydrophobic hormones to directly enter cells and interact with DNA makes them fundamentally different from hydrophilic hormones, which typically cannot penetrate the cell membrane and instead bind to receptors on the cell surface, triggering intracellular signaling cascades without directly influencing gene expression. This distinction is crucial for understanding how different hormones exert their physiological effects in the body.