AP BIOLOGY

Previous
Next

THE CELL

CELL COMMUNICATION

Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
Lidocaine is a local anesthetic that works as a temporary pain reliever. Lidocaine works by binding to voltage sensitive Na+ gates on pain receptors and prevents the gates from opening. Which of the following best describes why Lidocaine is an effective anesthetic?
A
Lidocaine limits sodium influx, which increases the production of presynaptic vesicles.
B
Lidocaine increases sodium influx, which stimulates the propagation of the action potential.
C
Lidocaine decreases sodium influx, which decreases the propagation of the action potential.
D
Lidocaine increases sodium influx, which decreases the release of neurotransmitters.
Explanation: 

Detailed explanation-1: -The principal mechanism of action of lidocaine as a local anaesthetic is through blockade of voltage-gated sodium channels (VGSCs) leading to a reversible block of action potential propagation.

Detailed explanation-2: -Mechanism of Action Lidocaine is 65% protein-bound to albumin and alpha1-acid glycoprotein in the plasma, giving it a medium duration of action compared to other local anesthetic agents. It is less lipid-soluble than other agents, limiting its overall potency.

Detailed explanation-3: -The P2X7 receptor plays an important role in pain regulation. Lidocaine can selectively inhibit the expression of the P2X7 receptor in Xenopus oocytes. It inhibits adenosine triphosphate-induced currents in P2X7 cells in a concentration-dependent manner. The maximum concentration for inhibition is 282 ± 45 mol/L.

Detailed explanation-4: -Lidocaine binds to voltage-gated sodium channels in a 1: 1 fashion and prevents the flow of sodium ions through the channel pore.

There is 1 question to complete.
Previous
Next