The Presence of Calcitonin Gene-Related Peptide and Its Receptors in Rat, Pig and Human Brain: Species Differences in Calcitonin Gene-Related Peptide Pharmacology

Pharmacology ◽  
2019 ◽  
Vol 104 (5-6) ◽  
pp. 332-341 ◽  
Author(s):  
Karin Warfvinge ◽  
Lars Edvinsson ◽  
Darryl S. Pickering ◽  
Majid Sheykhzade

Aim: The aim of present study is to investigate the binding characteristics of non-peptide calcitonin gene-related peptide (CGRP) receptor antagonists (i.e., gepants) in the brain membranes of rat, pig and human. Methods: The interaction of available gepants with the CGRP receptor was studied in the brain membranes of 3 different species using a radioligand competitive binding assay. In addition, the distribution of CGRP and its receptor component receptor activity modifying protein 1 (RAMP1) in rat cerebellum and cortex was explored using immunohistochemistry. Results: All gepants, except SB268262, displaced 100% of the radioligand specific binding in the brain tissue of all 3 species and showed highest affinity for CGRP receptors in human brain as compared to rat and pig brain membranes. Furthermore, radioligand binding studies revealed the presence of higher CGRP receptor density in human cerebellum compared to human cortex. The morphology, size and density of CGRP immunoreactive cells suggest that all cerebral cortical neurons were positive for CGRP. Slender receptor immunoreactive fibres were found spanning through the entire cortex. CGRP immunoreactivity was displayed in the cell soma of cerebellar Purkinje cells and in large neurons in the medial cerebellar nucleus. RAMP1 was found on the surface of the Purkinje cells and in parallel fibres, indicating presence in the granule cell axons. Conclusion: Cerebellum and cerebral cortex are rich in CGRP and CGRP receptors, which can be antagonized by gepants. However, all gepants display higher affinity for human CGRP receptors as compared to rat and pig CGRP receptors. Furthermore, human cerebellum seems to express higher density of CGRP receptors.

2012 ◽  
Vol 108 (2) ◽  
pp. 431-440 ◽  
Author(s):  
Oana Covasala ◽  
Sören L. Stirn ◽  
Stephanie Albrecht ◽  
Roberto De Col ◽  
Karl Messlinger

Calcitonin gene-related peptide (CGRP) is regarded as a key mediator in the generation of primary headaches. CGRP receptor antagonists reduce migraine pain in clinical trials and spinal trigeminal activity in animal experiments. The site of CGRP receptor inhibition causing these effects is debated. Activation and inhibition of CGRP receptors in the trigeminal ganglion may influence the activity of trigeminal afferents and hence of spinal trigeminal neurons. In anesthetized rats extracellular activity was recorded from neurons with meningeal afferent input in the spinal trigeminal nucleus caudalis. Mechanical stimuli were applied at regular intervals to receptive fields located in the exposed cranial dura mater. α-CGRP (10−5 M), the CGRP receptor antagonist olcegepant (10−3 M), or vehicle was injected through the infraorbital canal into the trigeminal ganglion. The injection of volumes caused transient discharges, but vehicle, CGRP, or olcegepant injection was not followed by significant changes in ongoing or mechanically evoked activity. In animals pretreated intravenously with the nitric oxide donor glyceryl trinitrate (GTN, 250 μg/kg) the mechanically evoked activity decreased after injection of CGRP and increased after injection of olcegepant. In conclusion, the activity of spinal trigeminal neurons with meningeal afferent input is normally not controlled by CGRP receptor activation or inhibition in the trigeminal ganglion. CGRP receptors in the trigeminal ganglion may influence neuronal activity evoked by mechanical stimulation of meningeal afferents only after pretreatment with GTN. Since it has previously been shown that olcegepant applied to the cranial dura mater is ineffective, trigeminal activity driven by meningeal afferent input is more likely to be controlled by CGRP receptors located centrally to the trigeminal ganglion.


2012 ◽  
Vol 22 (14) ◽  
pp. 4723-4727 ◽  
Author(s):  
Xiaojun Han ◽  
Rita L. Civiello ◽  
Charles M. Conway ◽  
Deborah A. Cook ◽  
Carl D. Davis ◽  
...  

Author(s):  
S. Padmaja ◽  
J. Mohan

Migraine is a mysterious disorder characterized by pulsating head ache, which is actually characterized to one side and comes in attacks which will be lasting for about 3-48 hours and can be associated with nausea,vomiting,sensitivity to sound,flashes of light,vertigoand diarrhoea [1]. Most of the drugs which are in current use for actue migraine like triptans, treats the disorder symptomatically. A novel group of drugs has been in research for the migraine which treats the disorder pathologically. Calcitonin gene – related peptide (CGRP) has a major role in the pathophysiology of the disorder and hence CGRP receptor antagonist, known as Gepants are in the research process [2]. Gepants are being studied for the efficacy of treating acute migraine [2]. This article will be a review article about the drug – Ubrogepant, which is approved for treatment of migraine with acute attacks in adults [3].


2021 ◽  
Author(s):  
Jiyoung Kim ◽  
Kyoungjune Pak ◽  
Gha-Hyun Lee ◽  
Jae Wook Cho ◽  
Hyun-Woo kim

Abstract Background: The pathophysiology of migraine has been researched incessantly, and it has been suggested that calcitonin gene-related peptide (CGRP) is associated with migraine attacks. CGRP receptor blockers are attracting attention for migraine prevention and treatment of acute episodes, and CGRP receptor antagonists have been shown to be effective in treating acute migraine headaches. This meta-analysis aimed to assess the effect of available CGRP receptor antagonists, focusing on their therapeutic doses for acute migraine treatment.Methods: We performed a systematic search of MEDLINE (from inception to March 2021) and EMBASE (from inception to March 2021) for English publications using the keywords “migraine” and “Calcitonin gene-related peptide,” limited to human studies.Results: Five studies that focused on examining the effects of CGRP receptor antagonists on acute migraine treatment met the eligibility criteria for this meta-analysis. The pooled analysis demonstrated that the CGRP receptor antagonist improved freedom from pain (OR=2.066, 95% confidence interval [CI] 1.766–2.418, I2=0%), absence of bothersome symptoms (OR=1.606, 95% CI=1.408–1.830, I2=0%), pain relief (OR=1.791, 95% CI=1.598–2.008, I2=0%), and freedom from nausea (OR=1.361, 95% CI=1.196–1.548, I2=0%), significantly more than the placebo. Conclusions: CGRP receptor antagonists are effective for acute migraine treatment and are expected to be used clinically as emerging therapeutic agents.


1997 ◽  
Vol 7 (20) ◽  
pp. 2673-2676 ◽  
Author(s):  
Robert A. Daines ◽  
Kelvin K.C. Sham ◽  
Jack J. Taggart ◽  
William D. Kingsbury ◽  
James Chan ◽  
...  

2021 ◽  
Vol 46 (4) ◽  
pp. 281
Author(s):  
F. Cipolla ◽  
M. Capi ◽  
L. Lionetto ◽  
D. De Bernardini ◽  
V. De Angelis ◽  
...  

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