Long term use of nitrates lead to decreased effect because of -

Ans. is 'b' i.e., SH groups in the enzyme o Tolerance develops to hemodynamic and antiischaemic effects of nitrates if they are continuously present in the body. No significant tolerance develops when nitrates are used intermittently. However; significant tolerance develops when nitrates are used continuously. This mechanism of nitrate tolerance is not well understood. The mechanism proposed is --> "Reduced ability to generate NO due to depletion of cellular SH radicals".