Regulation of Vascular Smooth muscle

Question 1

Explain the role of norepinephrine in vascular smooth muscle movement?

Answer 1

can bind to alpha 1 (GQ) or alpha 2 (Gi) to stimulate muscle contraction; Gi will decrease cAMP and Gq will activate IP3 to release Ca from the endoplasmic reticulum

Question 2

The MLCP is always active; however, the MLCK will only activate in response to what?

Answer 2

increased intracellular Ca concentration

Question 3

What are the main sources for extracellular Ca during muscle contraction?

Answer 3

L-type Ca channels; voltage-independent Ca channels

Question 4

What are the main sources for intracellular Ca during muscle contraction

Answer 4

CICR; IP3

Question 5

What plasma membrane channels aid in removing Ca from the VSMC

Answer 5

Ca pump; Na/Ca exchanger

Question 6

what intracellular proteins are involved in removing Ca from the VSMC

Answer 6

Ca binding proteins (calseqestrin & calreticulin); SERCA Ca-ATPase in SR

Question 7

Prostacyclin activates what mechanism to cause vasodilation?

Answer 7

adenylate cyclase; high levels of cAMP is associated w/ vasodilation