RESUMEN

Vasomotion is spontaneous or induced rhythmic changes in vascular tone or vessel diameter that lead to rhythmic changes in flow. While the vascular research community debates the physiological and pathophysiological consequence of vasomotion, there is a great need for experimental techniques that can address the role and dynamical properties of vasomotion in vivo. We apply laser speckle imaging to study spontaneous and drug induced vasomotion in retinal network of anesthetized rats. The results reveal a wide variety of dynamical patterns. Wavelet-based analysis shows that (i) spontaneous vasomotion occurs in anesthetized animals and (ii) vasomotion can be initiated by systemic administration of the thromboxane analogue U-46619 and the nitric-oxide donor S-nitroso-acetylDL-penicillamine (SNAP). Although these drugs activate different cellular pathways responsible for vasomotion, our approach can track the dynamical changes they cause.

Asunto(s)

Diagnóstico por Imagen/métodos , Retina/diagnóstico por imagen , Vasos Retinianos/diagnóstico por imagen , Sistema Vasomotor/diagnóstico por imagen , Ácido 15-Hidroxi-11 alfa,9 alfa-(epoximetano)prosta-5,13-dienoico/farmacología , Animales , Masculino , Donantes de Óxido Nítrico/farmacología , Ratas , Ratas Sprague-Dawley , Retina/efectos de los fármacos , Vasos Retinianos/efectos de los fármacos , S-Nitroso-N-Acetilpenicilamina/farmacología , Vasoconstricción/efectos de los fármacos , Vasoconstricción/fisiología , Vasoconstrictores/farmacología , Sistema Vasomotor/efectos de los fármacos

RESUMEN

Studies of vascular responses are usually performed on isolated vessels or on single vessels in vivo. This allows for precise measurements of diameter or blood flow. However, dynamical responses of the whole microvascular network are difficult to access experimentally. We suggest to use full-field laser speckle imaging to evaluate vascular responses of the retinal network. Image segmentation and vessel recognition algorithms together with response mapping allow us to analyze diameter changes and blood flow responses in the intact retinal network upon systemic administration of the vasoconstrictor angiotensin II, the vasodilator acetylcholine or on the changing level of anesthesia in in vivo rat preparations.