Cysteine nitroglycerin

NO is recognized as a mediator of bone cell metabolism, where it regulates osteoblast and osteoclast activity [141-143]. Osteoporosis, which frequently occurs in postmenopausal women, is a systemic skeletal disease associated with abnormal bone resorption. Addition of NO or NO donors to osteoclasts in vitro results in a reduction in bone resorption, whereas NO synthase inhibitors increase bone resorption, both in vitro and in vivo. Further research has shown that NO reduces bone resorption, via inhibition of the cysteine protease cathepsin K, which is believed to be a key protease in bone resorption. Most of the NO donors, i.e., nitroglycerin, 3-... 

Gruetter, C. A., Lemke, S. M., Dissociation of cysteine and glutathione levels from nitroglycerin-induced relaxation. 

Sellke FW, Tomanek RJ, Harrison DG. L-cysteine selectively potentiates nitroglycerin-induced dilation of small coronary microvessels. J Pharmacol Exp Ther 1991 258(1) 365-9. 

It is noteworthy that OTC can have other types of pharmaceutical applications than the delivery of cystein into the human body. For example, nitrated derivatives of OTC were recently patented as valuable coronary vasodilators which replace nitroglycerin without having its disadvantages (Ref. 276). An example of synthesis of these new interesting pharmaceuticals is given in scheme 223. 

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