<prompt> Increase in cytosolic calcium from intracellular storage, during smooth muscle contraction, isare due toCAMPCGMPIP3-DAGCa channel  <response>: In smooth muscle contraction, calcium channels are opened causing an influx of calcium into the cell. In smooth muscle cells, agonists such as neurotransmitters or hormones can induce an increase in i a release of intracellular stored calcium orand an influxof extracellular calcium. ... These channels control phenomena such as smooth musclecells proliferation andor contraction. REF: TEXTBOOK OF MEDICAL PHYSIOLOGY GEETHA N 2 EDITION, PAGE NO - 59 