Isosorbide dinitrate is an organic nitrate ester and nitric oxide (NO) donor in the same class as nitroglycerin.1 It induces vasodilation with IC50 values of 0.56 and 1.82 μM for isolated precontracted rabbit femoral vein and artery, respectively.2 Isosorbide dinitrate increases oxygenation of tumor tissue in vivo in a mouse xenograft model.3 It also inhibits platelet aggregation in vitro and in vivo at concentrations in the micromolar range.4 Formulations containing isosorbide dinitrate have been used for the treatment of angina pectoris.

References
1. Ahlner, J., Andersson, R.G., Torfgard, K., et al. Organic nitrate esters: Clinical use and mechanisms of actions. Pharmacol. Rev. 43(3), 351-423 (1991).
2. Toyoda, J., Hisayama, T., and Takayanagi, I. Nitro compounds (isosorbide dinitrate, 5-isosorbide mononitrate and glyceryl trinitrate) on the femoral vein and femoral artery. Gen. Pharmacol. 17(1), 89-91 (1986).
3. Jordan, B.F., Misson, P., Demeure, R., et al. Changes in tumor oxygenation/perfusion induced by the no donor, isosorbide dinitrate, in comparison with carbogen: Monitoring by EPR and MRI. Int. J. Radiat. Oncol. Biol. Phys. 48(2), 565-570 (2000).
4. De Caterina, R., Giannessi, D., Bernini, W., et al. Organic nitrates: Direct antiplatelet effects and synergism with prostacyclin. Antiplatelet effects of organic nitrates. Thromb. Haemost. 59(2), 207-211 (1988).