Receptors A macromolecule or the binding site located on the surface or inside the effector cell that serves to recognize the signal drug and initiate response to it, but itself has no action is defined as a Receptor. The largest no. of drugs do not bind directly to the effectors, viz, enzymes, channels, transporters, structural proteins, etc, but acts through specific regulatory macromolecules which controls the above listed factors. These regulatory macromolecules or the site on them which binds and interacts with the drug are called 'Receptors' (enzymes and structural proteins). These act as sensing elements on which endogenous messengers like hormones , neurotransmitters and other mediators act to bring about the desired biological response. Terms describing drug receptor interaction: Agonist: An agent that helps in activati...
Cell Injury The cell encounters variety of physiological stress and pathological stimuli which results in the change in its internal and external environment. This causes cell to undergo various adaptive responses and if the adaptive capability of the cell exceeds, then cell is said to develop cell injury. Given below is a quick overview highlighting the main aspects related to cell injury: