Daily variation in blood pressure in normal mice versus mice in which clock genes have been disrupted. In mice with normal clock protein (BMAL) function, blood pressure rises during the morning hours (left). In BMAL knockout mice, the daily variation in blood pressure vanishes (right).

Image Credit: Annie M. Curtis, PhD, and Garret A. FitzGerald, MD, University of Pennsylvania School of Medicine; Proceedings of the National Academy of Sciences.

Download high-resolution version (111 KB, JPEG, 300 DPI)