1. L-Arginine reduces downstream vascular contractility after flow-diverting device deployment: A preliminary study in a rabbit model
- Author
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Yong Hong Ding, Praveen Kolumam Parameswaran, Daying Dai, David F. Kallmes, Jennifer R. Ayers-Ringler, Zenith Khashim, and Ramanathan Kadirvel
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medicine.medical_specialty ,Vascular smooth muscle ,Arginine ,030204 cardiovascular system & hematology ,Nitric oxide ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Internal medicine ,medicine ,Animals ,Humans ,Effective treatment ,Aorta ,Vascular contractility ,business.industry ,Intracranial Aneurysm ,Original Articles ,chemistry ,Hemorrhagic complication ,Rabbit model ,Cardiology ,Rabbits ,business ,030217 neurology & neurosurgery - Abstract
Background Flow diverters (FDs) are an effective treatment for intracranial aneurysms, though not free from hemorrhagic complications. A previous study demonstrated increased vascular contractility after FD-implantation as a potential mechanism of distal complications. Our study aimed to investigate whether L-arginine medication affects vascular contractility following FD deployment in a rabbit model. Methods FDs were implanted in the aorta of normal rabbits (+FD, n = 10), with sham-operated aorta as controls (n = 5). L-Arginine was given in the drinking water (2.25% L-arginine hydrochloride) of half of the +FD animals (+FD/+Arg). Force contraction vascular contractility studies were performed on the aortic rings proximal and distal to the FD using an organ bath. Total eNOS, eNOS(pS1177), eNOS(pT495), COX-2, and S100A4 were quantified by western analysis on total protein lysates from aortic segments, normalizing to GAPDH. Results Mean vascular contractility was 53% higher in distal relative to proximal aortic segments (P = 0.0038) in +FD animals, but were not significantly different in +FD/+Arg animals, or in sham-operated controls. The +FD animals expressed significantly reduced levels of eNOS(pS1177) than sham-operated controls (P = 0.0335), while both the +FD and +FD/+Arg groups had reduced levels of eNOS(pT495) relative to sham-operated controls (P = 0.0331 and P = 0.0311, respectively). Conclusion These results suggest that L-arginine medication reduces distal vascular contractility after FD treatment via nitric oxide production and thus might mitigate risk for downstream complications. more...
- Published
- 2021
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