Sympathomimetics Flashcards

1
Q

On what five groups of tissue can we find alpha 1 receptors?

A
  1. Most vascular smooth muscle
  2. Iris
  3. Pilomotor smooth muscle
  4. Prostate and Uterus
  5. Heart.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What actions do the alpha 1 receptors have on the tissues they are located on?

A
  1. Contraction of the vascular smooth muscle beds (blood vessels, sphincters and bronchi).
  2. Contraction of the radial muscle of the iris (which dilates the pupil = mydriasis).
  3. Erects hair via the pilomotor smooth muscle
  4. Contraction of the prostate and uterus
  5. Increases force of contraction of the heart.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Which five tissues do we see a response from alpha 2 receptors?

A
  1. Platelets
  2. Adrenergic & cholinergic nerve terminals (presynaptic)
  3. Vascular smooth muscle
  4. GI tract
  5. CNS
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What actions do the alpha 2 receptors have on the tissues they are located on?

A

Cause:

  1. Aggregation of platelets
  2. Inhibit transmitter release from adrenergic and cholinergic nerve terminals
  3. Contraction of vascular smooth muscle post-synaptically or dilation presynaptically in the CNS.
  4. Relaxation of the GI tract presynaptically
  5. Sedation and analgesia in the CNS via decreased SNS outflow from the brain stem.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Why does blood vessel contraction not end up being a big deal with alpha 2 receptor activation?

A

Because the presynaptic postganglionic neuron alpha 2 receptors at the blood vessel act as ultra-short loop negative feedback as then release NE that NE feeds back to the receptor changing the potassium conductance and hyperpolarizing the cell inhibiting further release of NE.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Which tissue is more sensitive to lower levels of alpha 2 activation?

A

The brain.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the problem with antagonizing the alpha 2 receptor?

A

We lose our negative feedback and would end up with a shit ton of circulating NE.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What two main places are Beta 1 receptors found?

A
  1. Heart

2. Kidneys

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What actions do the Beta 1 receptors have at their tissue sites?

A
  1. Increase the force and rate of contraction of the heart

2. Stimulation of renin release.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What six places do we find Beta 2 receptors?

A
  1. Visceral smooth muscle (respiratory, uterine, vascular GI, GU)
  2. Mast cells
  3. Skeletal muscle
  4. Liver
  5. Pancreas
  6. Adrenergic nerve terminals.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What actions does the Beta 2 receptor have at the tissue level?

A
  1. Promotes smooth muscle relaxation
  2. Decreases histamine release
  3. Potassium uptake, dilation of vascular beds, tremor and increased speed of contraction
  4. Glycogenolysis
  5. Increased insulin secretion
  6. Increased release of NE
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Beta 3 targets? causing?

A
  1. Fat cells

2. Activates lipolysis and thermogenesis.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Which Dopamine receptor is found on smooth muscle?

A

D1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What kind of action does the D1 receptor cause to happen in the smooth muscle?

A

Post-synaptic location; dilates renal, mesenteric, coronary and cerebral blood vessels.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Which Dopamine receptor is found on nerve endings?

A

D2 receptor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What kind of action does the D2 receptor cause to happen in the nerve endings?

A

Pre-synaptic: modulates transmitter release (feedback); nausea and vomiting

17
Q

Name the three endogenous catecholamines.

A
  1. Epi
  2. NE
  3. Dopa
18
Q

Name two synthetic catecholaimines.

A
  1. Isoproterenol

2. Dobut

19
Q

What two types of classes of synthetic non-catecholamines do we have?

A
  1. Indirect

2. Direct

20
Q

Name 3 indirect acting synthetic non-catecholamines.

A
  1. Ephedrine
  2. mephenermine
  3. amphetamines
21
Q

Name two direct acting synthetic non-catecholamines..

A
  1. Phenylephrine

2. methoxamine

22
Q

Name two selective alpha-2 agonists.

A
  1. Clonidine

2. Dexmedetomidine

23
Q

Name three selective beta-2 adrenergic agonists

A
  1. Albuterol
  2. terbutaline
  3. Ritodrine
24
Q

Direct agonists have varied affinites for?

A

Alpha 1, Alpha 2, Beta 1 and Beta 2.

25
Q

Indirect agonists….

A

increase the release of NT

26
Q

In what four ways can catecholamines be terminated/metabolized?

A
  1. Reuptake
  2. MAO
  3. COMPT
  4. Lungs
27
Q

What are the two different reuptakes for catecholamines?

A
  1. Uptake 1- neuronal reuptake (the neuron that released it takes it back)
  2. Uptake II- extraneuronal uptake (neighboring area, slower with lower affinity so not as avid of a reuptake)
28
Q

In what two was are non-catecholamines terminated/metabolized?

A
  1. MAO

2. Urinary excretion (unchanged).