This paper may be helpful: Article Contraction of vascular smooth muscle in cell culture

"Visual evidence of cell contraction in the form of increased wrinkling was documented for cells exposed to angiotensin II, carbachol, and KCl. Decreases in cell tension occurred following treatment with isoproterenol, and those relaxing effects were overcome by subsequent treatment with the agonist carbachol."

Thank you, John! We’re actually also using Ang II to induce stiffening of the smooth muscle cells to test their contractile functions.