The acute effects of smokeless tobacco (snuff) on gingival blood flow in man.

Snuff-induced blood flow responses in the gingiva were evaluated in 22 healthy casual consumers of tobacco. Laser Doppler flowmetry (LDF) was used to measure blood flow simultaneously and continuously on two gingival sites (buccal aspect of the papillae between the upper lateral incisors and canines). In addition, measurements of skin blood flow in the forehead and palmar side of the left thumb were performed. Arterial blood pressure (BP) and heart rate (HR) were also recorded. Unilateral application of commercial snuff (500 mg, 1%) caused a marked and rapid increase in gingival blood flow (GBF) on the exposed side (p < 0.001). Blood flow increased also in the contralateral gingiva and forehead skin (p < 0.05). Skin blood flow in the thumb showed an insignificant decrease. BP and HR increased. Vascular conductance increased significantly in the snuff-exposed gingiva but not in the contralateral gingiva or the forehead. Vascular conductance was largely unaffected in the thumb. It is concluded that acute application of snuff, besides giving rise to typical changes in BP and HR, increases GBF in and around the exposed area, probably through activation of sensory nerves and the subsequent release of vasodilatory peptides from their peripheral endings. Blood flow in unexposed gingival and forehead skin may increase probably due to humoral or nervously mediated mechanisms. However, a passive pressure-induced hyperaemia in the unexposed gingiva and forehead skin can not be excluded.