Perfusion in hamster skin treated with glycerol

Background and Objective: The objective of this article is to quantify the effect of hyper-osmotic agent (glycerol) on blood velocity in hamster skin blood vessels measured with a dynamic imaging technique, laser speckle contrast imaging (LSCI). Study Design/Materials and Methods: In this study a dorsal skin-flap window was implanted on the hamster skin. The hyper-osmotic drug, that is, glycerol was delivered to the skin through the open dermal end of the window model. A two-dimensional map of blood flow of skin blood vessels was obtained from the speckle contrast (SC) images. Results: Preliminary studies demonstrated that hyperosmotic agents such as glycerol not only make tissue temporarily transparent, but also reduce blood flow. The blood perfusion was measured every 3 minutes for 36-66 minutes after diffusion of anhydrous glycerol. Blood flow in small capillaries was found to be reduced significantly within 3-9 minutes. Blood flow in larger blood vessels (i.e., all arteries and veins) decreased over time and some veins had significantly reduced blood flow within 36 minutes. At 24 hours, there was a further reduction in capillary blood perfusion whereas larger blood vessels regained flow compared to an hour after initial application of glycerol. Conclusion: Blood flow velocity and vessel diameter of the micro-vasculatures of hamster skin were reduced by the application of 100% anhydrous glycerol. At 24 hours, capillary perfusion remained depressed.