Related Experiment Video
Updated: May 25, 2025
Ex Vivo Release of Calcitonin Gene-Related Peptide from the Trigeminovascular System in Rodents
Published on: May 16, 2022
CamKIIα and VPAC1 Expressions in the Caudal Trigeminal Nucleus of Rats After Systemic Nitroglycerin Treatment:
Gábor Nagy-Grócz1,2, Eleonóra Spekker3, Tamás Körtési1,2,4
1Department of Theoretical Health Sciences and Health Management, Faculty of Health Sciences and Social Studies, University of Szeged, Temesvári Krt. 31, H-6726 Szeged, Hungary.
Abstract:
Migraines are a frequently occurring neurological condition that affects up to 16% of the global population. The precise pathomechanism of the disease remains unknown, but from animal and human observations, it appears that calcium/calmodulin-dependent protein kinase II alpha (CamKIIα), pituitary adenylate cyclase-activating polypeptide (PACAP), and vasoactive intestinal polypeptide (VIP) are involved in its pathogenesis. One of the animal models of migraines uses the systemic administration of nitroglycerin (NTG), which, as a nitric oxide (NO) donor, initiates a self-amplifying process in the trigeminal system, leading to central sensitization. Endocannabinoids, such as anandamide (AEA), are thought to play a modulatory role in trigeminal activation and sensitization phenomena. In the present experiment, we aimed to investigate the effect of NTG and AEA on CamKIIα, PACAP/VIP, and vasoactive intestinal polypeptide type 1 receptor (VPAC1) expression levels in the upper cervical spinal cord (C1-C2) of rats, where trigeminal nociceptive afferents are clustered. Four groups of animals were formed: in the first group, the rats received only the vehicle; in the second group, they were treated with an intraperitoneal injection of NTG (10 mg/kg); animals in the third and fourth groups received AEA (2 × 5 mg/kg) half an hour before and one hour after the placebo or treatment with NTG. Four hours after the placebo/NTG injection, the animals were transcardially perfused, and the cervical spinal cords were removed for Western blot. Our results show that both NTG and AEA alone can increase the expression of CamKIIα and VPAC1 in the C1-C2 segments. Interestingly, the combination of NTG and AEA had no such effect on these markers, possibly due to various negative feedback mechanisms.
Insights
Nitroglycerin (NTG) and anandamide (AEA) alone increase key migraine-related protein expression in rats. However, combining NTG and AEA did not produce the same effect, suggesting potential negative feedback mechanisms in migraine pathogenesis.
Area of Science:
- Neuroscience
- Molecular Biology
- Pharmacology
Background:
- Migraines are a prevalent neurological disorder with an unknown precise pathomechanism.
- Calcium/calmodulin-dependent protein kinase II alpha (CamKIIα), pituitary adenylate cyclase-activating polypeptide (PACAP), and vasoactive intestinal polypeptide (VIP) are implicated in migraine pathogenesis.
- Nitroglycerin (NTG), a nitric oxide (NO) donor, induces a migraine model via trigeminal system activation and central sensitization.
Purpose of the Study:
- To investigate the effects of NTG and anandamide (AEA) on specific protein expression in the rat upper cervical spinal cord (C1-C2).
- To examine the expression levels of CamKIIα, PACAP/VIP, and vasoactive intestinal polypeptide type 1 receptor (VPAC1) following NTG and AEA administration.
Main Methods:
- Utilized a rat model for migraines involving systemic administration of NTG.
- Administered anandamide (AEA) at specific time points relative to NTG or placebo.
- Analyzed protein expression levels of CamKIIα, PACAP/VIP, and VPAC1 in the C1-C2 spinal cord segments using Western blot.
Main Results:
- Both NTG and AEA administered alone significantly increased the expression of CamKIIα and VPAC1 in the C1-C2 segments.
- The combined administration of NTG and AEA did not result in an increase in CamKIIα and VPAC1 expression.
- These findings suggest that AEA may modulate NTG-induced changes, potentially through negative feedback mechanisms.
Conclusions:
- Single administration of NTG or AEA influences key molecular markers associated with migraine in the trigeminal system.
- The combination of NTG and AEA appears to counteract these effects, indicating a complex regulatory interaction.
- Further research is warranted to elucidate the precise mechanisms underlying these interactions and their therapeutic implications for migraine treatment.
