Physiological agonism and antagonism

Physiological agonism and antagonism refers to the interaction of chemical substances within the human body that either stimulate or inhibit the function of biological receptors. These interactions play a crucial role in the regulation of various physiological processes, including metabolism, immune response, and neurotransmission.

Physiological Agonism

A physiological agonist is a substance that binds to a receptor and triggers a response in the cell. This is often a biochemical response that results in a change in cell function. Physiological agonists can be endogenous (produced within the body) or exogenous (introduced from outside the body). Examples of endogenous physiological agonists include hormones and neurotransmitters, while exogenous physiological agonists can include drugs or toxins.

Physiological Antagonism

In contrast, a physiological antagonist is a substance that binds to a receptor but does not trigger a response in the cell. Instead, it blocks the receptor and prevents it from being activated by an agonist. Like agonists, physiological antagonists can also be endogenous or exogenous. An example of an endogenous physiological antagonist is the hormone insulin, which acts as an antagonist to glucagon in the regulation of blood sugar levels.

Role in Pharmacology

Understanding the principles of physiological agonism and antagonism is fundamental to the field of pharmacology. Many drugs are designed to act as either agonists or antagonists to specific receptors in order to treat various medical conditions. For example, beta blockers are a type of drug that acts as an antagonist to beta-adrenergic receptors, reducing the effects of adrenaline and noradrenaline and thus lowering blood pressure.

See Also

• Receptor (biochemistry)
• Pharmacodynamics
• Drug interaction