Increase of meningeal blood flow after electrical stimulation of rat dura mater encephali: mediation by calcitonin gene-related peptide.
1. The dura mater encephali of the rat was exposed and the blood flow around branches of the medial meningeal artery was monitored with a laser Doppler flowmeter. Changes in the meningeal blood flow (MBF) following electrical stimulation of the dura mater at a parasagittal site were registered. The effects of human calcitonin gene-related peptide (h-alpha CGRP) and the CGRP antagonist (h-alpha CGRP8-37) on the MBF were tested. 2. Electrical stimulation with rectangular pulses of 0.5 ms, 10-20 V, 5-10 Hz and a duration of 30 s caused an increase of the MBF in 14 out of 16 rats tested. The increases were dependent on stimulus strength and frequency. 3. The increase in MBF was inhibited in a dose-dependent manner by topical application of 0.1 ml of h-alpha CGRP8-37 at concentrations of 10(-7) - 10(-5) M. The highest dose abolished the increase in MBF. 4. Topical administration of 0.1 ml of h-alpha CGRP at a concentration of 10(-4) M increased the basal MBF by 15% on average. 5. It is suggested that the increase in MBF following electrical stimulation of the dura mater is mediated by the release of CGRP. The contribution of the dural afferent and sympathetic and parasympathetic efferent nerve fibres to this response are discussed.
Kurosawa
M
M
Department of Physiology, University of Würzburg, Germany.
Messlinger
K
K
Pawlak
M
M
Schmidt
R F
RF
D000818:Animals; D001783:Blood Flow Velocity / Q000502:physiology*; D002116:Calcitonin / Q000235:genetics; D015740:Calcitonin Gene-Related Peptide / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004388:Dura Mater / Q000098:blood supply / Q000502:physiology*; D004558:Electric Stimulation; D005260:Female; D008297:Male; D008576:Meningeal Arteries / Q000187:drug effects* / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D013997:Time Factors; D014664:Vasodilation / Q000187:drug effects / Q000502:physiology
D002116:Calcitonin; D015740:Calcitonin Gene-Related Peptide