Vasoreactivity of the Murine External Jugular Vein and Carotid Artery

Cho, Jae Min; Shiu, Yan-Ting; Symons, J. David; Lee, Timmy

doi:10.1159/000508129

Cited by 2 publications

(4 citation statements)

References 25 publications

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“…Rats were euthanized at 1 week ( n = 3–4 per group) or 4 weeks ( n = 6–9 per group). The AVF vessels were harvested en bloc and placed in buffered zinc formalin for 48 h. The fixed tissues were embedded in paraffin and serially sectioned in 5 μm sections, following the standard histology procedures as previously described by us ( Kwon et al, 2015 ; Shiu et al, 2016 ; Cho et al, 2020 ). Sections were stained with hematoxylin and eosin (H&E) and Verhoeff-Van Gieson (VVG) stain for subsequent morphometric analysis.…”

Section: Methodsmentioning

confidence: 99%

Natural Vascular Scaffolding Treatment Promotes Outward Remodeling During Arteriovenous Fistula Development in Rats

Shiu

Tey

et al. 2021

Front. Bioeng. Biotechnol.

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Following creation, an arteriovenous fistula (AVF) must mature (i.e., enlarge lumen to allow high blood flow) before being used for hemodialysis. AVF maturation failure rates are high, and currently, there are no effective therapy to treat this problem. The maturation process is likely affected by the integrity of the vascular extracellular matrix (ECM). Natural Vascular Scaffolding (NVS) Therapy is a new technology that interlinks collagen and elastin via photoactivation of a locally delivered small molecule (4-amino-1,8-naphtalamide). We hypothesized that NVS Therapy may improve AVF remodeling by preserving ECM integrity. AVFs were created in Wistar male rats by connecting the femoral vein (end) to femoral artery (side) in the same limb. Immediately after blood flow was restored to dilate the femoral vein by arterial pressure, a 10 μl-drop of the NVS compound (2 mg/ml) was placed on the anastomosis perivascularly. Following 5-min incubation, the NVS treated area was exposed to 1-min illumination by 450-nm light. The control group received 10 μl-drop of phosphate buffered saline (PBS) and the same light activation. The skin was closed, and rats were euthanized 4 weeks (n = 6–9 per group) post-AVF creation for histology, morphometry, immunohistochemistry (IHC), and multiphoton microscopy for second-harmonic-generation evaluation of collagen fibers. The vascular thickness was similar in both groups. The AVF vein’s open lumen area and % open lumen area in NVS-treated rats were significantly larger than in PBS-treated rats (4.2-fold p = 0.014 and 2-fold p = 0.009, respectively). The inflammatory markers IL-6 and MMP-9 in the AVF walls were significantly decreased in the NVS group than the PBS group. Collagen fibers in the vascular wall trended toward perpendicular alignment to the lumen circumference in the NVS-treated AVFs, with more defined shape but less area than in the PBS-treated AVFs. These results indicate that the NVS Therapy exerted changes in collagen, which may influence AVF maturation. Rats tolerated the NVS treatment well, and the lack of cell death by the treatment was confirmed in cell culture experiments. These results suggest that NVS treatment is safe and may have therapeutic potential by facilitating lumen expansion to enhanced AVF maturation in patients.

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Section: Methodsmentioning

confidence: 99%

Natural Vascular Scaffolding Treatment Promotes Outward Remodeling During Arteriovenous Fistula Development in Rats

Shiu

Tey

et al. 2021

Front. Bioeng. Biotechnol.

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“…Exposing arterial rings to ACh following PE precontraction provides an assessment of endothelial-dependent, receptor-mediated vasodilation. 27 28 In the current study, human arteries exposed, relatively briefly, to surgically used doses of papaverine and verapamil had a 65% lesser peak ACh-mediated relaxation than the control. In contrast, the arteries exposed to a surgically used dose of lidocaine did not affect ACh-mediated relaxation ( Fig.…”

Section: Discussionmentioning

confidence: 55%

“…Exposing arterial rings to SNP following PE preconstriction provides an assessment of endothelium-independent vasodilation. 27,29 There was a 22% lesser SNP-mediated relaxation in the arterial rings exposed to papaverine than the control, whereas lidocaine and verapamil had no effect (►Fig. 3).…”

Section: Lasting Effects Of Papaverine Lidocaine and Verapamil On End...mentioning

confidence: 98%

“…The length-tension relationship was determined to ensure each arterial ring was studied at the optimal length for maximal contraction. 27 After the 2-hour equilibration period, the arterial rings were slowly brought to a resting tension of 8 mN at a rate of 2 mN per 10 minutes. The PSS in the baths was then exchanged with PSS containing 100 mM potassium chloride (PSS-KCl), and maximal tension was measured.…”

Section: Length-tension Relationship and Maximal Contractionmentioning

confidence: 99%

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Lasting Effects of Surgically Used Topical Vasodilators on DIEP Artery Vascular Function

Kofoed,

Tuncer,

Kwok

et al. 2024

J Reconstr Microsurg

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Background Surgeons routinely apply papaverine, lidocaine, or verapamil to produce acute vasodilation and prevent vasospasms during microvascular surgeries. There is evidence that topical vasodilators may induce postoperative endothelial and smooth muscle dysfunction, which would present after the acute vasodilatory effects of the topical drugs wear off. Therefore, the purpose of the current study was to evaluate the lasting effects of papaverine, lidocaine, and verapamil on human deep inferior epigastric perforator artery vasodilatory function after the acute effects of the topical drugs had worn off. Methods Deep inferior epigastric arterial samples were obtained from 12 patients during surgery. Each artery was dissected into four rings which where incubated for 1 minute in either physiological saline solution (control), papaverine (30 mg/mL), lidocaine (20 mg/mL), or verapamil (2.5 mg/mL), followed by a 2-hour washout. Endothelial-dependent and -independent vasorelaxation were then assessed by the isometric tension responses to acetylcholine or sodium nitroprusside, respectively. Results Peak acetylcholine-evoked vasorelaxation (mean ± standard deviation) was not different between control (62 ± 23%) and lidocaine (57 ± 18%, p = 0.881), but was reduced (all p < 0.002) in papaverine (22 ± 27%) and verapamil (22 ± 20%). Peak sodium nitroprusside-evoked vasorelaxation was not different (all p > 0.692) among control (132 ± 35%), lidocaine (121 ± 22%), and verapamil (127 ± 22%), but was less in papaverine (104 ± 41%; p = 0.045) than control. Conclusion Surgically used doses of papaverine and verapamil, but not lidocaine, have lasting negative effects on arterial vasodilatory function despite the acute effects of the drugs having worn off. These findings, in conjunction with the spasmolytic properties of each drug, may help guide the selection of an optimal topical vasodilator for use during microvascular surgeries.

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Vasoreactivity of the Murine External Jugular Vein and Carotid Artery

Cited by 2 publications

References 25 publications

Natural Vascular Scaffolding Treatment Promotes Outward Remodeling During Arteriovenous Fistula Development in Rats

Natural Vascular Scaffolding Treatment Promotes Outward Remodeling During Arteriovenous Fistula Development in Rats

Lasting Effects of Surgically Used Topical Vasodilators on DIEP Artery Vascular Function

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