Which of the Following Relaxes Smooth Muscle

Question

Which of the following relaxes smooth muscle?
A) Stimulat ion of MLCK
B) Opening of voltage-gated Ca2+ ch an ne ls
C) Inhibit ion of MLCP
D) NO (nitric oxide)
E) Release of Ca2+ from the SR

Accepted Answer

NO (nitric oxide) is known to relax smooth muscle by activating guanylate cyclase, which increases cyclic GMP levels, leading to smooth muscle relaxation.