What does paracrine signaling refer to?

Paracrine signaling refers to the process where signal molecules, or ligands, are released by a signaling cell and act on neighboring target cells within a short distance. This type of signaling allows for localized communication between cells, facilitating functions such as growth, inflammation, and tissue repair.

In paracrine signaling, the molecules do not enter the circulation but instead diffuse through the extracellular fluid to reach their targets. This close range is what distinguishes paracrine signaling from other types such as endocrine signaling, where hormones are released into the bloodstream to affect distant cells, or autocrine signaling, where a cell responds to its own signals. Overall, the key characteristic of paracrine signaling is its focus on immediate neighbors, allowing for quick responses to changes in the cellular environment.