<prompt> Which of the following statement is true about nitratesActs by raising CGMP which causes dephosphorylation of MLCKMetabolized by glutathione reductaseUsed in achlasia cardiaAll of the above  <response>: Nitrates acts by releasing nitric oxide which increases cGMP that cause dephosphorylation of myosin light chain kinase. These are preferential dilators of venules because glutathione reductase enzyme that release NO from nitrates is principally present at these sites. These agents are smooth muscle relaxants and can be used in colic and achlasia cardia Refer kDT 6e p523 