SMPD1 and Hypercalcemia: Moreover, overexpression of Smpd1 gene in SMCs using Smpd1trg/SMcre mice largely enhanced calcification in the aortic medial and coronary arterial wall than their littermates during hypercalcaemia induced by high doses of Vit D. However, using amitriptyline, a pharmacological inhibitor of ASM significantly reduced both aortic and coronary arterial wall calcification.