Related Experiment Videos
Exhaled nitric oxide as a marker for organic nitrate tolerance
M Husain1, C Adrie, F Ichinose
1Department of Anaesthesia, Harvard Medical School, Massachusetts General Hospital, Boston 02114.
Circulation
|June 1, 1994
Summary
Biochemical tolerance to nitroglycerin develops, as shown by reduced exhaled nitric oxide (NO) levels in lambs. This noninvasive measurement indicates decreased NO release and tolerance to nitroglycerin's effects.
Area of Science:
- Pharmacology
- Biochemistry
- Physiology
Background:
- Organic nitrates are used clinically, but tolerance can develop.
- Nitric oxide (NO) plays a role in vasodilation and nitrate effects.
- Measuring exhaled NO may offer insights into nitrate tolerance.
Purpose of the Study:
- To investigate the development of biochemical tolerance to organic nitrates.
- To assess if exhaled nitric oxide (NO) levels reflect nitrate tolerance.
- To compare tolerance development between nitroglycerin and sodium nitroprusside.
Main Methods:
- Lambs received intravenous (IV) nitroglycerin or sodium nitroprusside.
- Exhaled nitric oxide (NO) levels were measured using chemiluminescence.
- Systemic hypotensive responses were monitored during drug challenges.
Main Results:
- Nitroglycerin infusion led to significantly reduced exhaled NO levels and attenuated hypotensive responses.
- Tolerance to nitroglycerin was observed, while sodium nitroprusside did not induce similar changes.
- A 12-hour recovery period restored NO excretion and systemic responses to nitroglycerin.
Conclusions:
- Exhaled NO measurements provide noninvasive, in vivo evidence of biochemical tolerance to nitroglycerin.
- Reduced pulmonary NO release correlates with systemic tolerance to nitroglycerin vasodilation.
- This method offers a potential tool for monitoring nitrate tolerance.