Question

Questions are applied for the following drugs: atenolol, labetalol, celiprolol. clonidine

Molecular target(s) of the drug?

Is the drug a receptor agonist? If yes, what receptor(s)?

Is the drug a receptor antagonist? If yes, what receptor(s)

Does the drug cause vascular smooth muscle contraction or relaxation?

Will the drug inhibit a vascular smooth muscle contraction induced by phenylephrine?

If yes, the action via which one of the following three mechanisms:

(1) the drug inhibits the binding of phenylephrine to its receptor; OR

(2) the drug inhibits the signal transduction induced by phenylephrine; OR

(3) the drug causes vasodilation.

Will the drug inhibit a vascular smooth muscle contraction induced by angiotensin II?

If yes, the action via which one of the following three mechanisms:

(1) the drug inhibits the binding of angiotensin II to its receptor; OR

(2) the drug inhibits the signal transduction induced by angiotensin II; OR

(3) the drug causes vasodilation.

Answer 1

ANSWER

1. This drugs helps to control hypertension.

* Atenolol act by beta blocker.

* Labetalol act by alpha and beta receptor blocker.

*. Celiprolol act by beta blocker.

*. Clonidine act by stimulating alpha 2 adrenergic blocker.

2. Yes .  

alpha 2 agonist .

clonidine:-

It is selective alpha 2 agonist. it stimulates alpha 2 receptors in the CNs it decrease central sympthetic out flow and blocks the release of nor adrenaline leads to fall in blood pressure.

3. Yes.

Celiprolol :- it is vasoactive beta 1 adenoceptor antagonist with partial beta 2 agonist activity.because of this beta 2 agonist activity the blood pressure falls down.

4. This drugs cause vascular smooth muscle relaxation by widening vessels and allow to blood flow easily . (vasodilation) which results to decrease blood pressure.

5. Yes

The drug inhibits the binding of phenylephrine to its receptor; OR.

6. Yes.

The drug inhibits the binding of angiotensin 2 to its receptor ; OR.