PLASMA EXTRAVASATION IN DIFFERENT TISSUES INNERVATED BY TRIGEMINAL NERVE INDUCED BY ELECTRICAL STIMULATION ON TRIGEMINAL GANGLION

Dura mater is a pain-sensitive tissue where the vascular supply is richly innervated by trigeminal nerve fibers, and it is considered to be an important structure playing a possibe role in the pathophysiology of migraine. We determined the plasma extravasation by 125 I-BSA trace method in different tissues innervated by trigeminal nerve following unilateral electrical stimulation of the trigeminal ganglion. An ipsilateral 125I-BSA extravasation was found in the dura mater, temporalis muscle, superior and inferior gingival mucosa,and conjectiva following electrical stimulation(5Hz, 1. 2mA, 5msec for 5min)of the rat trigeminal ganglion(p0. 01 in all cases). The ratio of atimulated/unstimulated side (cpm/mg) in a descending order was temporalis muscle(1. 98±0. 02)conjunctiva(1. 97±0. 06) dura mater(1. 67±0. 21) superior and inferior gingival mucosa (1. 62±0.09 ). No extravasation in the brain tissue was observed following electrical stimulation of trigeminal ganglion. The results suggest that neurogenic duramatter plasma extravasation may play an important role in the mechanism of vascular headache.