Calcitonin gene-related peptide (CGRP): Responsible for the increased blood flow induced by the stimulation of sensory nerves

1994 ◽  
Vol 41 (S2) ◽  
pp. C262-C263 ◽  
Author(s):  
S. D. Brain ◽  
K. J. Escott ◽  
S. R. Hughes ◽  
R. Kajekar
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.


1989 ◽  
Vol 256 (3) ◽  
Author(s):  
P�r Stj�rne ◽  
Lars Lundblad ◽  
Anders �ngg�rd ◽  
Tomas H�kfelt ◽  
JanM. Lundberg

2010 ◽  
Vol 88 (10) ◽  
pp. 949-959 ◽  
Author(s):  
Jian-Zhe Li ◽  
Jun Peng ◽  
Li Xiao ◽  
Yi-Shuai Zhang ◽  
Mei-Chun Liao ◽  
...  

Dysfunction of capsaicin-sensitive sensory nerves is involved in cardiac remodeling, and rutaecarpine has been shown to exert a beneficial effect on cardiac function through activating the sensory nerves. This study was conducted to explore the potential inhibitory effect of rutaecarpine on cardiac remodeling and the underlying mechanisms. A rat cardiac remodeling model was established by injection of isoprenaline (5 mg/kg per day, s.c.) for 10 days. Rutaecarpine (10 or 40 mg/kg, i.g.) was coadministrated with isoprenaline to evaluate the effect of rutaecarpine on cardiac remodeling. After echocardiographic analysis was performed, blood samples were collected to quantify calcitonin gene-related peptide (CGRP), dorsal root ganglia were isolated for examining CGRP mRNA expression, and the hearts were weighed and saved for evaluating the parameters related to apoptosis and hypertrophy. Isoprenaline significantly increased the ratio of left ventricle weight to body weight, the cross-sectional area of cardiomyocytes, cardiac apoptosis, and collagen deposition concomitantly with decreased CGRP production, which were reversed by rutaecarpine treatment. The beneficial effects of rutaecarpine were attenuated by pretreatment with capsaicin, which selectively depleted CGRP. These results suggest that rutaecarpine was able to reverse isoprenaline-induced cardiac remodeling through stimulating CGRP production.


1989 ◽  
Vol 256 (2) ◽  
pp. E331-E335 ◽  
Author(s):  
T. Chiba ◽  
A. Yamaguchi ◽  
T. Yamatani ◽  
A. Nakamura ◽  
T. Morishita ◽  
...  

From this study, we predicted that the human calcitonin gene-related peptide (hCGRP) fragment hCGRP-(8-37) would be a selective antagonist for CGRP receptors but an agonist for calcitonin (CT) receptors. In rat liver plasma membrane, where CGRP receptors predominate and CT appears to act through these receptors, hCGRP-(8-37) dose dependently displaced 125I-[Tyr0]rat CGRP binding. However, hCGRP-(8-37) had no effect on adenylate cyclase activity in liver plasma membrane. Furthermore, hCGRP-(8-37) inhibited adenylate cyclase activation induced not only by hCGRP but also by hCT. On the other hand, in LLC-PK1 cells, where calcitonin receptors are abundant and CGRP appears to act via these receptors, the bindings of 125I-[Tyr0]rat CGRP and 125I-hCT were both inhibited by hCGRP-(8-37). In contrast to liver membranes, interaction of hCGRP-(8-37) with these receptors led to stimulation of adenosine 3',5'-cyclic monophosphate (cAMP) production in LLC-PK1 cells, and moreover, this fragment did not inhibit the increased production of cAMP induced not only by hCT but also by hCGRP. Thus hCGRP-(8-37) appears to be a useful tool for determining whether the action of CGRP as well as that of CT is mediated via specific CGRP receptors or CT receptors.


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.


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