| SHORT COMMUNICATION
|Year : 1997 | Volume
| Issue : 6 | Page : 429-432
Effect of methylene blue on endothelium-dependent relaxation by acetylcholine in monkey aortic strips
S Savithiri, A Kuruvilla
Objective: To study the effect of methylene blue on monkey aortic strips with intact and damaged endothelium.
Methods: The monkeys were anaesthetised and a section of thoracic aorta was removed and cut into transverse strips. Vessels were suspended in a 10 ml organ bath containing Hanks physiological solution oxygenated with 100% oxygen. The tissues were equilibrated for 90 minutes under a resting tension of 3g. Isometric tensions were recorded with a force displacement transducer and recorded on a student physiograph. After the equilibration period, strips were used for relaxation studies.
Results: In isolated monkey aortic strips, acetylcholine was found to cause relaxation in strips possessing intact endothelial cells. It produces contraction in strips with damaged endothelial cells. The percentage relaxation by acetylcholine in the absence of methylene blue in aortic strips with endothelium was 30.43 ( 8.3 and in the presence of methylene blue(an inhibitor of guanylate cyclase), the percent relaxation to acetylcholine was 9.05 ( 4.9. The contraction in damaged strips was enhanced in the presence of methylene blue.
Conclusion: Methylene blue decreased the relaxation response to acetylcholine in monkey strips with intact endothelium. In strips with damaged endothelium, methylene blue increased the contraction caused by acetylcholine.
Source of Support: None, Conflict of Interest: None