Electrical stimulation of the peripheral stump of the cut and perineurally capsaicin-pretreated saphenous nerve evokes antidromic vasodilatation preceded by a short vasoconstriction in the dorsal skin of the hindpaw in the rat. These microcirculatory changes were measured by laser-Doppler flowmetry. Blood flow increase induced by nerve stimulation was completely abolished by 1 microgram/kg resiniferatoxin (RTX), while the inicial blood flow decrease was significantly reduced or totally inhibited by subsequent treatments with an alpha adrenergic receptor antagonist (GYKI-12743) and a neuropeptide Y functional antagonist (alpha-trinositol) in response to 10 Hz and 3 HZ stimulations, respectively.