Noninvasive characterization of light‐induced acute inflammation in the Pallid bat

Abstract

It has been observed that ultraviolet (UV) and visible light induce vasodilation (i.e. photodilation) and increases local blood flow in skin. It is, however, not known whether the resulting vasodilation is a primary, NO-mediated effect, or a secondary effect of ultraviolet light phototoxicity. To address this question, we utilized the Pallid bat wing model at TAMU. The wing is thin and transparent, allowing for intravital microscopy without invasive procedures (leading to confounding effects of anesthesia and trauma). TAMU, however, has the only extant colony of bats dedicated to vascular research. To access unique animal and laboratory resources, we employed a novel use of Internet technology we refer to as ‘e-Research’, consisting of logging into a remote computer capable of manipulating positioning of an intravital microscope. To characterize an acute inflammatory response, we exposed the Pallid bat wing to brightfield and ultraviolet light and counted interactive leukocytes along the walls of post-capillary venules. We observed a measurable, but not significant, increase in leukocyte activity. In this study, we showed that light-induced vasodilation is not a consequence of an acute inflammatory response (i.e. tissue damage). Our unique approach allows us to explore basic microvascular function and acute inflammatory responses with well-established intravital microscopic methods.