quiz4b - 2. Haloperidol binds to both X and Y receptor...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Quiz 4b – St. Pete True/False (2 pts. each) Many antipsychotic drugs have Parkinsonian-like side effects but clozapine doesn’t (Figure 1). You have just discovered two new antipsychotic drugs: Drugs X and Y which cause Parkinson-like symptoms with differing efficacies. You measure and compare the efficacies and potencies of these drugs to displace the specific binding of 3 H-dopamine from homogenized brain samples. Only 70% of the receptors occupied by 3 H-dopamine will bind Drug X (Subtype X) while only 30% of the receptors will bind Drug Y (Subtype Y). Which of the following conclusions are true after examining the resulting competition curves shown in Figure 2? If you don’t have any evidence to prove that the statement is true, then answer false. 1. Sulpiride has a lower affinity for the "X" site compared to clozapine’s affinity for the “X” site.
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: 2. Haloperidol binds to both X and Y receptor subtypes but Drug Y does not. 3. The IC 50 values for sulpiride to bind to the two subtypes are more alike than are the IC 50 values for haloperidol to bind to the two subtypes. 4. Agonists for the "X" subtype appear to cause Parkinson-like side effects by positively activating that receptor subtype. 5. Drug Y is a partial agonist at Y receptors. 6. Drug X is a full agonist at Y receptors. 7. Clozapine is an agonist for the "Y" subtype. Figure 1. 20 40 60 80 100 0.01 0.03 0.1 0.3 1 3 10 30 100 300 1000 3000 Drug Dose (mg) % Patients with Parkinson side effects Sulp. Halo. Cloz. Y X Figure 2. 10 20 30 40 50 60 70 80 90 100 0.01 0.03 0.1 0.3 1 3 10 30 100 300 1000 3000 Competing Drug concentration (nM) % Specific 3H-DA Binding Drug Y Clozapine Drug X Halo. Sulp....
View Full Document

This note was uploaded on 04/27/2009 for the course CHM 2046 taught by Professor Veige/martin during the Spring '07 term at University of Florida.

Page1 / 2

quiz4b - 2. Haloperidol binds to both X and Y receptor...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online