Question

Drugs such as fenfluramine that were used to treat obesity exerted an inhibition of appetite by?

1) Blocking serotonin receptor activity in the PVN
2) Causing the release of NPY from cells in the arcuate
3) Activating CART receptors
4) Altering serotonin activity in the PVN
5) Acting as a serotonin agonist in the brain

Answer 1

Fenfluramine, used to treat obesity, suppresses appetite by acting as a serotonin agonist in the brain, specifically altering serotonin activity in the PVN and thus inhibiting food intake.

Step-by-step explanation:

Drugs such as fenfluramine that were used to treat obesity exerted an inhibition of appetite by altering serotonin activity in the PVN (paraventricular nucleus of the hypothalamus).

Serotonin is a neurotransmitter that typically has an inhibitory effect on eating behavior. Anti-obesity drugs like fenfluramine act mainly by increasing serotonin levels or mimicking its action, leading to a reduction in appetite. Fenfluramine functions as a serotonin agonist, meaning it binds to serotonin receptors and activates them, much like serotonin itself would. This activation results in decreased food intake and consequently reduced body weight in obese patients.

The correct answer is that fenfluramine acts as a serotonin agonist in the brain, thereby altering the serotonin activity in the PVN, which is responsible for suppressing appetite and food intake.