Vaso dilators & Vaso constrictors 9.14

Question 1

Alpha agonist - vd or vc?

Answer 1

Vasoconstrictor

Question 2

Endothelin 1 - vd or vc?

Answer 2

Vasoconstrictor

Question 3

Angiotensin 2 - vd or vc?

Answer 3

Vasoconstrictor

Question 4

Thromboxane A2 - vd or vc?

Answer 4

Vasoconstrictor

Question 5

Histamine - vd or vc?

Answer 5

Vasodilator

Question 6

Bradykinin - vd or vc?

Answer 6

Vasodilator

Question 7

Substance P - vd or vc?

Answer 7

Vasodilator

Question 8

Acetylcholine - vd or vc?

Answer 8

Vasodilator

Question 9

Increase in vascular muscle intracellular Ca2+ causes?

Answer 9

Vasoconstriction (contraction of smooth muscle) - “filling it with Ca2+ makes it stiff and contracted”

Question 10

Decrease in intracellular Ca2+ causes?

Answer 10

Vasodilation (relaxation of smooth muscle) - “emptying the Ca2+ makes it empty and floppy / relaxed”

Question 11

What is the basic process for increasing intracellular Ca2+ by vasoconstrictors?

Answer 11

Vasoconstrictor binds to cell membrane G protein receptor –> 2 signals produced: 1. Open Ca channels and let more Ca2+ INTO cell. 2. Sarcoplasmic reticulum releases Ca2+ into cell cytoplasm.

Question 12

Noradrenaline - vd or vc?

Answer 12

Vasoconstrictor

Question 13

Adrenaline - vd or vc?

Answer 13

Vasoconstrictor

Question 14

What is basic process for decreasing intracellular Ca2+ by vasodilators?

Answer 14

Vasodilator binds to epithelial cell receptor–> Nitric oxide synthase (eNOS) turns L arginine into Nitric Oxide –> NO enters smooth muscle cell & acts on Guanylyl cyclase –> synth. cGMP. cGMP causes: 1. Blockage of Ca2+ entry into cell, 2. Absorption of Ca2+ into sarcoplasmic reticulum.

Question 15

Prostacyclin (Prostaglandin I2) - vd or vc?

Answer 15

Vasodilator