vasoactive-intestinal-peptide and Trigeminal-Neuralgia

The cerebral circulation is innervated by sympathetic, parasympathetic, and sensory nerves, which store a considerable number of neurotransmitters. The role of these has been evaluated in primary headaches. A clear association between head pain and the release of calcitonin gene-related peptide was demonstrated. In cluster headache and in a case of chronic paroxysmal headache there was in addition the release of vasoactive intestinal peptide, which was associated with the facial symptoms (nasal congestion, rhinorrhea). In parallel with sumatriptan treatment, head pain subsided and neuropeptide release normalized. These data show the involvement of sensory and parasympathetic mechanisms in the pathophysiology of primary headaches.

Topics: Blood Vessels; Calcitonin Gene-Related Peptide; Calcium Channels; Cerebrovascular Circulation; Cluster Headache; Headache; Humans; Migraine Disorders; Sympathetic Nervous System; Trigeminal Neuralgia; Vascular Headaches; Vasoactive Intestinal Peptide

To investigate the expression levels of calcitonin gene-related peptide (CGRP), substance P (SP), vasoactive intestinal peptide (VIP), and β-endorphin in the cerebrospinal fluid (CSF) and peripheral blood of patients with primary trigeminal neuralgia (TN).. We included 20 patients with primary TN who underwent percutaneous radiofrequency thermocoagulation and collected four types of samples from all of them: sample A: CSF samples; sample B: peripheral blood samples; sample C: peripheral blood samples collected one day before the operation; sample D: peripheral blood samples withdrawn one day after the operation. Another 20 CSF samples of patients with nervous system disease or gynecological disease were collected as a control (sample E). Samples A and B were obtained at the same time. We also evaluated the expression of CGRP, SP, β-endorphin, and VIP by visual analog scale (VAS) scores one day before and one day after the operation. In addition, heart rate (HR) at baseline and at the time of sample collection, mean arterial pressure (MAP), and all side effects of the procedure were recorded.. Significance were found concerning about CGRP, SP, β-endorphin, and VIP in TN patients and the controls (P<0.001). The expression of CGRP, SP, and VIP in sample A was higher than that in sample E. However, the β-endorphin level in sample A was lower than that in sample E. There was a positive correlation between sample A and B regarding the expression of CGRP, SP, β-endorphin, and VIP (P<0. 01). There was no relationship between the time of disease onset and the expression of CGRP, SP, β-endorphin, and VIP in sample A and sample B (P>0.05). No difference was detected between the neuropeptides levels in samples B and C (P>0.05). Notably, VAS in sample D was significantly lower than that in sample C (P<0.01). Finally, there was no difference between the intraoperative HR and MAP values in the studied samples.. In primary TN patients, the blood levels of CGRP, SP, β-endorphin, and VIP were associated with those in CSF samples. There was a significant difference between the levels of the four neuropeptides in CSF and control samples. Our results also indicated that the levels of neuropeptides in blood samples can be tested for those in CSF. The disease onset and duration exerted insignificant effects on the production and release of CGRP, SP, β-endorphin, and VIP.

Topics: Adult; Aged; beta-Endorphin; Biomarkers; Calcitonin Gene-Related Peptide; Electrocoagulation; Female; Humans; Male; Middle Aged; Neuropeptides; Substance P; Trigeminal Neuralgia; Vasoactive Intestinal Peptide

PACAP and VIP are members of the VIP/secretin/glucagon family of peptides with neurotransmitter, neuroprotective, and neurotrophic functions. PACAP and VIP are known to be upregulated in primary sensory neurons following nerve injury, implying that these neuropeptides could be mediators of sensory transmission in neuropathic pain states. Nerve injury at the level of the trigeminal root is thought to be the prime cause of trigeminal neuralgia. Since cross-excitation (a chemically-mediated form of nonsynaptic transmission) within the TG is postulated to play a central role in trigeminal neuralgia, we studied the expression of PACAP and VIP receptors in the TG by RT PCR and immunocytochemistry. Of the three known receptors (PAC1, VPAC1 and VPAC2), RT PCR revealed the presence of mRNA for VPAC2 and several splice variants of the PAC1 receptor. Immunocytochemistry showed PAC1 and VPAC2 to be present in small-diameter TG neurons. Thus, PACAP and VIP are potential mediators of cross-excitation in the TG.

Topics: Afferent Pathways; Alternative Splicing; Animals; Cell Communication; Cells, Cultured; Immunohistochemistry; Male; Neurons, Afferent; Neuropeptides; Nociceptors; Pituitary Adenylate Cyclase-Activating Polypeptide; Protein Isoforms; Rats; Rats, Sprague-Dawley; Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide; Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide, Type I; Receptors, Pituitary Hormone; Receptors, Vasoactive Intestinal Peptide; Receptors, Vasoactive Intestinal Peptide, Type II; Receptors, Vasoactive Intestinal Polypeptide, Type I; RNA, Messenger; Signal Transduction; Trigeminal Ganglion; Trigeminal Neuralgia; Vasoactive Intestinal Peptide

The aim of this study was to observe whether vasoactive intestinal polypeptide (VIP) participated in the attack of trigeminal neuralgia, and to understand further its pathogenetic mechanism.. Sixteen patients were studied. During the attacks the venous blood was sampled from both the external jugular vein and cubital fossa vein ipsilateral to the pain, and after operations the venous blood from the external jugular vein was sampled again, the external jugular vein blood of eleven normal volunteers was collected as the control. Plasma levels of VIP were determined using sensitive radioimmunoassays.. During the attacks of trigeminal neuralgia the levels of VIP in the external jugular vein blood were significantly higher than that in the cubital fossa vein blood, postoperative external jugular vein blood and the external jugular vein blood of normal volunteers.. VIP indeed participates in the attack of trigeminal neuralgia in the local region, the role of VIP may be relating to enhancing the effects of substance P in local neurogenic inflammation.

Topics: Adult; Aged; Female; Humans; Male; Middle Aged; Radioimmunoassay; Substance P; Trigeminal Neuralgia; Vasoactive Intestinal Peptide