37.1 Effect of vibration on skin blood flow; an in-vivo experimental study in a microcirculatory model      

Gojiro Nakagami; Manabu Takano; Hiromi Sanada; Atsuko Kitagawa; Shigeru Ichioka; Junko Sugama; Hideki Yokogawa; Naomi Sekiya, The University of Tokyo         

We studied the effects of vibration on skin microcirculation to investigate the applicability of vibration to clinical use for prevention and treatment of ischemic wounds. A vibration applicator with a 47 Hz frequency and 600, 800, 1000mVpp of vibrational intensity was applied horizontally to the ear auricle of male hairless mice (n = 6 in each group) for 10 minutes under inhalation anesthesia. A control group (n = 6) received no vibration. Venular blood flow was measured using an intravital videomicroscope at baseline, and 0, 5, and 15 minutes after stopping the vibration. Significant increases were observed in the 600 mVpp group at 5 and 15 minutes after starting vibrations compared to controls (P = .002, and P = .046, respectively). We also detected increased blood flow in the 800 mVpp group (P = .028) and 1000 (P = .012) at 5 minutes after stopping the vibration; however, these increases were attenuated at 15 minutes after. These results indicated that direct skin vibration at 47 Hz frequency improves the skin blood flow. Nitric oxide production induced by the mechanical stresses of vibration including shear stress, compression and cell stretching on to the endothelial cells via mechanotransduction was a possible mechanism to explain the vasodilation of venules. Negative feedback was considered to have occurred in the 800 and 1000 mVpp, indicating that caution needs to be exercised in respect to vibrational intensity for its clinical use.