Validation of Laser Doppler Single Point Protocol for Measurement of Resistance Arteries Reactivity

Validation of Laser Doppler Single Point Protocol for Measurement of Resistance Arteries Reactivity

• Autor
• Karla Caroline Marques de Oliveira
• Co-autores
• Anízia Karoline de Oliveira , Pollyana Ribeiro Castro , Lucíola da Silva Barcelos , Fabiana Simão Machado , Stêfany Bruno de Assis Cau , Mauro Martins Teixeira
• Resumo

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  Introduction: Laser Doppler Imaging (LDI), used to scan superficial blood flow, can be set up to quantitative analysis of blood flow by single point positioning (LDIsp) on vessels surface, which has been poorly explored to examine vascular function. Herein, we investigated the sensitivity of LDIsp to detect perfusion alterations of resistance arteries in response to vasoactive agents exogenously administrated in exposed mesenteric arterial bed of healthy and infected mice under anesthesia. Material and Methods: All the procedures were approved by Animal Use Ethics Committee (CEUA-UFMG) under the protocol 330/2018. Male Balb/C, aging 10-week-old, were anesthetized and submitted to a median laparotomy to the mesenteric arch exposition in a warm plate. The laser Doppler Imager Control (Moor Instruments) was positioned on a mesenteric resistance artery (second branch). Basal perfusion was recorded for 3 minutes. Then, noradrenaline (10-6 M, 50 ?L) and acetylcholine (10-6 M, 50 ?L) were sequentially administrated, each one being recorded for 3 minutes. Additionally, the same protocol was performed in a pathological condition (malaria). For that, animals were infected with 106 erythrocytes parasitized with Plasmodium chabaudi and LDIsp was performed 7 days post-infection. Results were analyzed through Two-way ANOVA and Tukey’s post-test. Results: The absolute values of local perfusion varied considerably (CV = 28%), a consistent reduction was observed after noradrenaline (45.5%, P<0.001), and a slight increase of perfusion after exogenously administered acetylcholine (14%, P>0.05). For comparison, local perfusion was measured in animals with malaria. A significative reduction of basal perfusion between healthy and infected group was found (AU: 5,565 ± 1,559 Vs. 1,172 ± 822 P<0.05). Importantly, neither noradrenaline nor acetylcholine significantly changes vascular perfusion in P. chabaudi-infected mice. Conclusion: In conclusion, we described a LDIsp-based experimental protocol which provides a quantitative evaluation of mesenteric arteries response to vasoactive agents in vivo and which allows intergroup comparisons.

   

• Palavras-chave
• Vascular function, Laser doppler imaging, resistance arteries
• Modalidade
• Pôster
• Área Temática
• Disfunção endotelial