What is the type of Antagonism when 2 different drugs act on 2 different sites on the same cell and their response is opposite to each other ?
**Core Concept**
Pharmacological antagonism can be classified based on the mechanism of interaction between two drugs. In this scenario, we are discussing a specific type of antagonism where two different drugs act on two different sites on the same cell, leading to opposite responses.
**Why the Correct Answer is Right**
This type of antagonism is known as **non-competitive antagonism**. When two drugs bind to different receptors on the same cell, one drug can cause an agonistic effect, while the other drug can cause an antagonistic effect. This is because the drugs are acting on distinct sites, which can lead to opposing physiological outcomes. For example, in the case of a G-protein coupled receptor, one drug may activate the receptor, while another drug may block the receptor's ability to activate downstream signaling pathways.
**Why Each Wrong Option is Incorrect**
* **Option A:** This is incorrect because non-competitive antagonism involves two drugs acting on different sites, whereas non-competitive antagonism typically involves a drug binding to an active site on an enzyme or receptor, altering its shape and function.
* **Option B:** This is incorrect because competitive antagonism involves two drugs competing for the same binding site on a receptor, which is not the case in this scenario.
* **Option C:** This is incorrect because physiological antagonism involves two drugs that produce opposite effects through different mechanisms, but they do not necessarily act on the same cell or receptor.
**Clinical Pearl / High-Yield Fact**
When considering pharmacological antagonism, it's essential to remember that the site of action and the mechanism of interaction between two drugs can significantly impact the type of antagonism observed.
**Correct Answer: C.** Non-competitive antagonism.