Talk:Modes of toxic action

"Types" section is a direct copy and paste from the following book: PK Gupta, in Illustrated Toxicology, 2018
'''I have copy and pasted the start of chapter 3.2 from this book below for your reference: ''' Mechanism of toxicity PK Gupta, in Illustrated Toxicology, 2018

3.2 Mode of Action Q. What are the different types of mode of toxic actions?

There are two major types of modes of toxic action: 1. Nonspecific acting toxicants are those that produce narcosis.

2. Specific acting toxicants are those that are nonnarcotic and that produce a specific action at a specific target site.

Q. What is nonspecific type of mode of action?

Nonspecific acting modes of toxic action result in narcosis; therefore, narcosis is a mode of toxic action. Narcosis is defined as a generalized depression in biological activity due to the presence of toxicant molecules in the organism. The target site and mechanism of toxic action through which narcosis affects organisms are still unclear, but there are hypotheses that support that it occurs through alterations in the cell membranes at specific sites of the membranes, such as the lipid layers or the proteins bound to the membranes. Even though continuous exposure to a narcotic toxicant can produce death, if the exposure to the toxicant is stopped, narcosis can be reversible.

Q. What do you mean by specific type of mode of actions?

Toxicants that at low concentrations modify or inhibit some biological process by binding at a specific site or molecule have a specific acting mode of toxic action. However, at high enough concentrations, toxicants with specific acting modes of toxic actions can produce narcosis that may or may not be reversible. Nevertheless, the specific action of the toxicant is always shown first because it requires lower concentrations.

Q. What are the different specific modes of toxic actions? • Uncouplers of oxidative phosphorylation: The action involves toxicants that uncouple the two processes that occur in oxidative phosphorylation: electron transfer and adenosine triphosphate (ATP) production.

• Acetylcholinesterase (AChE) inhibitors: AChE is an enzyme associated with nerve synapses that it is designed to regulate nerve impulses by breaking down the neurotransmitter acetylcholine (ACh). When toxicants bind to AChE, they inhibit the breakdown of ACh. This results in continued nerve impulses across the synapses, which eventually cause nerve system damage. Examples of AChE inhibitors are organophosphates and carbamates.

• Irritants: These are chemicals that cause an inflammatory effect on living tissue by chemical action at the site of contact. The resulting effect of irritants is an increase in the volume of cells due to a change in size (hypertrophy) or an increase in the number of cells (hyperplasia). Examples of irritants are benzaldehyde, acrolein, zinc sulfate, and chlorine.

• Central nervous system (CNS) seizure agents: CNS seizure agents inhibit cellular signaling by acting as receptor antagonists. They result in the inhibition of biological responses. Examples of CNS seizure agents are organochlorine pesticides.

• Respiratory blockers: These are toxicants that affect respiration by interfering with the electron transport chain in the mitochondria. Examples of respiratory blockers are rotenone and cyanide. — Preceding unsigned comment added by 121.223.4.3 (talk) 21:48, 21 May 2020 (UTC)