What is the Origin of Cell Receptor Sensitivity?

Derived from cellular biology and pharmacology, the term describes the crucial initial step in signal transduction where a cell perceives and reacts to external or internal cues. This concept is foundational to endocrinology, as hormones must bind to receptors to exert their effects.

What is the Mechanism of Cell Receptor Sensitivity?

Sensitivity is modulated by receptor trafficking, where receptors are internalized or recycled, and by phosphorylation or dephosphorylation events that alter their binding affinity. Chronic overexposure to a ligand, such as insulin or cortisol, often leads to downregulation and desensitization of the receptors. Conversely, periods of ligand absence can promote upregulation and re-sensitization, a key process for maintaining cellular responsiveness.

Cell Receptor Sensitivity ∞ Area

Cell Receptor Sensitivity

Meaning

The measure of a target cell’s responsiveness to a specific signaling molecule, such as a hormone or neurotransmitter, determined by the density, affinity, and functional state of its surface or intracellular receptors. Optimal sensitivity ensures that a biological response is generated by a physiological concentration of the ligand. A loss of sensitivity, or desensitization, is a hallmark of many endocrine disorders and aging processes, requiring clinical attention.