Headache Granule On Experimental Migraine Rats Aqueduct Periaqueductal Gray Substance P-like Immunoreactive Neurons Fos Expression,

The present study demonstrates the distribution and relationship of c-fos on cogene expressing protein product (Fos)-like immuno- reactivity neurons and substance P(SP)-like immunoreactivity neurons in the periaqueductal gray matter (PAG) of the rat by means of the immunocytochemistry after subcutaneous injection of nitroglycerin [glyceryl trinitrate(GTN)]. Systemic administration GTN(10mg/kg, s. c.) increased the expression of Fos-like immunoreactivity neurons and the release of immunoreactive SP in PAG. Double-labeled immunohistochemical study showed that some Fos-positive neurons were immunostained for SP. The results suggested that SP might be involved in noxious stimulus-evoked c-fos expression in the PAG. SP could act as neurotransmitters, at least in part, to transmit the sensory stimuli to the higher brain centers or to evoke the function of the endogenous antinociceptive system.The effect of Toutongping(a Chinese herbal drug granules) on the significantly reduce the Fos expression induced by systemic administration GTN was determined. Toutongping also significantly increases SP-like immunoreactivity neurons at 2h after systemic administration GTN as the same as ergotamine.