Which type of ligand is associated with slow-onset, long-lasting intracellular mediated responses?

• A. Hydrophilic ligands
• B. Hydrophobic ligands
• C. Affectionate ligands
• D. Agonistic ligands

Answer: (B)

The correct answer is hydrophobic ligands. These ligands are typically nonpolar molecules that can easily diffuse through cell membranes due to their lipid-soluble nature. Once inside the cell, hydrophobic ligands often bind to intracellular receptors, which then activate specific gene expressions and coordinate long-term cellular responses.

This slow-onset and long-lasting effect is primarily because hydrophobic ligands often influence transcription processes, resulting in the production of proteins that can alter various cellular functions over time. Their action leads to sustained changes in the cell's physiology compared to other types of ligands, which may trigger rapid but transient responses.

In contrast, other types of ligands might interact with membrane-bound receptors that usually initiate quick-signaling cascades, leading to immediate cellular responses rather than prolonged effects. Thus, hydrophobic ligands are well-suited for inducing changes that require time to develop and persist, aligning them with slow-onset, long-lasting intracellular mediated responses.