Nitric Oxide Releases Calcitonin-Gene-Related Peptide from Rat Dura mater Encephali Promoting Increases in Meningeal Blood Flow

2002 ◽  
Vol 39 (6) ◽  
pp. 489-496 ◽  
Author(s):  
Thomas Strecker ◽  
Mária Dux ◽  
Karl Messlinger
Cephalalgia ◽  
2002 ◽  
Vol 22 (3) ◽  
pp. 233-241 ◽  
Author(s):  
T Strecker ◽  
M Dux ◽  
K Messlinger

This study addresses possible interactions of the vasodilators nitric oxide (NO), calcitonin gene-related peptide (CGRP) and prostaglandins, which may be implicated in the generation of vascular headaches. Local application of the NO donator diethylamine-NONOate (NONOate) to the exposed dura mater encephali of the rat caused dose-dependent increases in meningeal blood flow recorded by laser Doppler flowmetry. Pre-application of the CGRP receptor antagonist CGRP8-37 significantly attenuated the evoked blood flow increases, while the cyclooxygenase inhibitors acetylsalicylic acid and metamizol were only marginally effective. Stimulation of rat dura mater with NONOate in vitro caused increases in CGRP release. NADPH- diaphorase activity indicating NO production was restricted to the endothelium of dural arterial vessels. We conclude that increases in meningeal blood flow caused by NO depend partly on the release and vasodilatory action of CGRP from dural afferents, while prostaglandins are not significantly involved.


1995 ◽  
Vol 73 (7) ◽  
pp. 1020-1024 ◽  
Author(s):  
K. Meßlinger ◽  
U. Hanesch ◽  
M. Kurosawa ◽  
M. Pawlak ◽  
R. F. Schmidt

The parietal dura mater encephali of the rat was shown by immunohistochemistry to be densely innervated by calcitonin gene related peptide (CGRP) immunoreactive nerve fibers spreading around the medial meningeal artery and its branches. Electrical stimulation of the dural surface (10–20 V, 5–10 Hz, 10–30 min) caused a depletion of CGRP-immunopositive fibers, suggesting a release of CGRP. The dural blood flow around branches of the medial meningeal artery was also monitored with a laser Doppler flowmeter. Short periods (30 s) of electrical stimulation with parameters that presumably released CGRP from nerve fibers caused a repeatable and constant increase of the blood flow for 1–2 min. This evoked increase could dose dependently be inhibited by topical application of the CGRP antagonist hCGRP8–37. Accordingly, administration of hCGRP increased the basal blood flow. We conclude that stimulation of trigeminal afferents innervating the dura mater releases CGRP from peptidergic afferent terminals, thereby causing vasodilatation and increasing the meningeal blood flow, an important element of neurogenic inflammation.Key words: dura mater encephali, afferent nerve fibers, calcitonin gene related peptide, immunohistochemistry, laser Doppler flowmetry.


Cephalalgia ◽  
2007 ◽  
Vol 27 (6) ◽  
pp. 481-491 ◽  
Author(s):  
N Schwenger ◽  
M Dux ◽  
R de Col ◽  
R Carr ◽  
K Messlinger

Calcitonin gene-related peptide (CGRP), nitric oxide (NO) and histamine are implicated in primary headaches but their role in vascular and nociceptive events in the dura mater is not well described. In an in vitro preparation of the hemisected rat skull, CGRP and histamine release from the cranial dura was measured using enzyme-linked immunoassays. While the NO donator NONOate (10-4 M) was without effect, CGRP (10-5 M) induced considerable histamine release from the rat cranial dura, which was blocked by the CGRP receptor antagonist CGRP8-37 (10-5 M). Conversely, histamine (10-4 M) did not stimulate CGRP release. In vitro recordings from single rat meningeal afferents showed that only one of 12 mechanically identified units but several mechanically insensitive units responded to histamine (up to 10-5 M). Increases in meningeal blood flow after histamine application (10-4 M) to the rat cranial dura remained unchanged during CGRP receptor blockade with CGRP8-37, inhibition of NO synthesis with L-NAME (20 mg/kg i.v.) and H3 receptor blockade with thioperamide (10-4 M). We conclude that histamine produces direct vasodilatation and activates a subset of largely non-mechanically sensitive, non-CGRP containing afferents in the rat meninges. Histamine is released from meningeal mast cells which are stimulated by CGRP. Similar mechanisms may be involved in the pathogenesis of headaches.


2000 ◽  
Vol 279 (4) ◽  
pp. H1654-H1660 ◽  
Author(s):  
Yasushi Takahashi ◽  
Maartje De Vroomen ◽  
Christine Roman ◽  
Michael A. Heymann

Fetal pulmonary blood flow is regulated by various vasoactive substances. One, calcitonin gene-related peptide (CGRP), increases pulmonary blood flow. We examined four key physiological mechanisms underlying this response using the blocker drugs CGRP receptor blocker (CGRP8–37), nitric oxide synthase inhibitor [ N ω-nitro-l-arginine (l-NNA)], adenosine triphosphate-dependent potassium (KATP) channel blocker (glibenclamide), and cyclooxygenase inhibitor (indomethacin) in 17 near-term fetal sheep. Catheters were placed in the left (LPA) and main pulmonary arteries, and an ultrasonic flow transducer was placed around the LPA to measure flow continuously. CGRP was injected directly into the LPA (mean 1.02 μg/kg) before and after blockade, and responses to CGRP were statistically compared. Before blockade, CGRP increased LPA blood flow from 23 ± 25 to 145 ± 77 ml/min (means ± SD), and these increases were significantly attenuated by CGRP8–37( n = 6; 91% inhibition), l-NNA ( n = 6; 86% inhibition), and glibenclamide ( n = 6; 69% inhibition). No significant changes were found with indomethacin ( n = 6; 4% inhibition). Thus, in the fetal pulmonary circulation, CGRP increases pulmonary blood flow not only through its specific receptor but also, in part, through nitric oxide release and KATP channel activation.


2019 ◽  
Vol 24 (2) ◽  
pp. 383-397 ◽  
Author(s):  
Mária Dux ◽  
Alexandru Babes ◽  
Jessica Manchen ◽  
Julika Sertel‐Nakajima ◽  
Birgit Vogler ◽  
...  

2006 ◽  
Vol 148 (4) ◽  
pp. 536-543 ◽  
Author(s):  
Thomas Denekas ◽  
Markus Tröltzsch ◽  
Axel Vater ◽  
Sven Klussmann ◽  
Karl Messlinger

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