Steroid hormones typically act on which type of receptor?

Steroid hormones primarily act on nuclear receptors due to their lipophilic (fat-soluble) nature, which enables them to easily pass through the cell membrane. Once inside the cell, these hormones bind to specific intracellular receptors within the cytoplasm or the nucleus. This hormone-receptor complex then translocates to the nucleus if it is initially in the cytoplasm, where it binds to DNA and influences gene expression by functioning as a transcription factor.

This mechanism allows steroid hormones to regulate a wide variety of physiological processes, including metabolism, immune response, and development, by altering how specific genes are expressed. The binding of steroid hormones to nuclear receptors leads to long-term effects on cell function, which is distinct from the rapid signaling cascades that often involve cell surface receptors, such as G-protein coupled receptors or tyrosine kinase receptors. These surface receptors tend to mediate immediate effects, primarily through second messenger systems, which differ fundamentally from the genomic effects initiated by steroid hormone interaction with nuclear receptors.