Microvascular Structure of the Rat Heart

Although the capillaries associated with the heart are critical in providing the heart with oxygen and nutrients, there has been little research visualizing the three-dimensional structure of these capillary beds. This research is being conducted to visualize the vasculature and three-dimensional structure of the capillary beds in rat hearts. In this study, hearts from both WKY (Wistar-Kyoto) rats and SHR (spontaneously hypertensive rats) were examined using scanning electron microscopy. To prepare the tissue, rats were anesthetized with inaction, and a polyurethane resin was infused via an aortic catheter. Once the plastic resin polymerized, the heart was removed and placed into a concentrated potassium hydroxide solution to digest the tissue around the plastic cast. The remaining structure was critical point dried and sputter coated with gold palladium. Our results show that the capillaries of the heart appear to parallel the muscle fibers in arrangement, and are highly interconnected. This pattern may change during hypertensive conditions