neuropeptide-y and Migraine-Disorders

The high prevalence of osteoporosis, observed in multiple sclerosis (MS) patients, has been attributed to reduced mobility and or the use of disease-modifying drugs. However, MS-impaired cardiovascular autonomic nervous system (ANS) function has the potential of reducing bone mass density (BMD) by altering the expression and/or function of the neuronal, systemic, and local mediators of bone remodeling. This review describes the complex regulation of bone homeostasis with a focus on MS, providing evidence that ANS dysfunction and low BMD are intertwined with MS inflammatory and neurodegenerative processes, and with other MS-related morbidities, including depression, fatigue, and migraine. Strategies for improving ANS function could reduce the prevalence of MS osteoporosis and slow the rate of MS progression, with a significant positive impact on patients' quality of life.

Topics: Adiponectin; Autonomic Nervous System; Bone Density; Bone Remodeling; Brain; Cardiovascular System; Depression; Endocannabinoids; Fatigue; Humans; Inflammation; Leptin; Migraine Disorders; Multiple Sclerosis; Nerve Degeneration; Neuropeptide Y; Osteocalcin; Osteopontin; Osteoporosis; Osteoprotegerin; Parathyroid Hormone; RANK Ligand; Serotonin; Vitamin D

The hypothalamus is involved in the regulation of homeostatic mechanisms and migraine-related trigeminal nociception and as such has been hypothesized to play a central role in the migraine syndrome from the earliest stages of the attack. The hypothalamus hosts many key neuropeptide systems that have been postulated to play a role in this pathophysiology. Such neuropeptides include but are not exclusive too orexins, oxytocin, neuropeptide Y, and pituitary adenylate cyclase activating protein, which will be the focus of this review. Each of these peptides has its own unique physiological role and as such many preclinical studies have been conducted targeting these peptide systems with evidence supporting their role in migraine pathophysiology. Preclinical studies have also begun to explore potential therapeutic compounds targeting these systems with some success in all cases. Clinical efficacy of dual orexin receptor antagonists and intranasal oxytocin have been tested; however, both have yet to demonstrate clinical effect. Despite this, there were limitations in these cases and strong arguments can be made for the further development of intranasal oxytocin for migraine prophylaxis. Regarding neuropeptide Y, work has yet to begun in a clinical setting, and clinical trials for pituitary adenylate cyclase activating protein are just beginning to be established with much optimism. Regardless, it is becoming increasingly clear the prominent role that the hypothalamus and its peptide systems have in migraine pathophysiology. Much work is required to better understand this system and the early stages of the attack to develop more targeted and effective therapies aimed at reducing attack susceptibility with the potential to prevent the attack all together.

Topics: Animals; Clinical Trials as Topic; Humans; Hypothalamus; Migraine Disorders; Neuropeptide Y; Nociception; Orexins; Oxytocin; Pituitary Adenylate Cyclase-Activating Polypeptide; Treatment Outcome

Migraine is a common disabling neurovascular primary headache disorder. The pathomechanism is not clear, but extensive preclinical and clinical studies are ongoing. The structural basis of the leading hypothesis is the trigeminovascular system, which includes the trigeminal ganglion, the meningeal vasculature, and the distinct nuclei of the brainstem, the thalamus and the somatosensory cortex. This review covers the effects of sensory (calcitonin gene-related peptide, pituitary adenylate cyclase-activating polypeptide and substance P), sympathetic (neuropeptide Y) and parasympathetic (vasoactive intestinal peptide) migraine-related neuropeptides and the functions of somatostatin, nociceptin and the orexins in the trigeminovascular system. These neuropeptides may take part in neurogenic inflammation (plasma protein extravasation and vasodilatation) of the intracranial vasculature and peripheral and central sensitization of the trigeminal system. The results of human clinical studies are discussed with regard to the alterations in these neuropeptides in the plasma, saliva and cerebrospinal fluid during or between migraine attacks, and the therapeutic possibilities involving migraine-related neuropeptides in the acute and prophylactic treatment of migraine headache are surveyed.

Topics: Animals; Brain; Calcitonin Gene-Related Peptide; Humans; Migraine Disorders; Neurons; Neuropeptide Y; Neuropeptides; Pituitary Adenylate Cyclase-Activating Polypeptide; Substance P; Trigeminal Ganglion; Vasoactive Intestinal Peptide

The neuropeptides substance P, calcitonin gene-related peptide (CGRP) and vasoactive intestinal polypeptide (VIP) have been considered as important mediators in migraine and other primary headaches. CGRP and VIP have been found at increased concentrations in jugular venous plasma during attacks of migraine or cluster headache, and CGRP receptor antagonists have recently been shown to be effective in migraine therapy. Substance P and CGRP are produced from a subset of trigeminal afferents, whereas VIP derives from parasympathetic efferents. Release of these neuropeptides in the meninges can cause arterial vasodilatation, mast cell degranulation and plasma extravasation in animal experiments, but only CGRP seems to be relevant in migraine. Animal models have confirmed the important role of CGRP in meningeal nociception. The activity of spinal trigeminal neurons is a sensitive integrative measure of trigeminal activity and is partly under the control of CGRP, most likely via central mechanisms. CGRP released from central terminals of trigeminal afferents in the spinal trigeminal nucleus seems to facilitate nociceptive transmission via presynaptic mechanisms. The central effect of CGRP is substantiated by suppression of nociceptive c-fos activation and neuronal activity in the spinal trigeminal nucleus following CGRP receptor inhibition. These proposed functions are supported by the localization of CGRP receptor components in the rat cranial dura mater, trigeminal ganglion and spinal trigeminal nucleus. The currently available data indicate multiple sites of CGRP action in trigeminal nociception and the pathogenesis of migraine; however, central CGRP receptors are likely to be the essential targets in the treatment of migraine using CGRP receptor antagonists.

Topics: Animals; Calcitonin Gene-Related Peptide; Calcitonin Gene-Related Peptide Receptor Antagonists; Dura Mater; Humans; Membrane Potentials; Migraine Disorders; Neurokinin A; Neuropeptide Y; Piperazines; Quinazolines; Receptors, Calcitonin Gene-Related Peptide; Substance P; Trigeminal Ganglion; Trigeminal Nucleus, Spinal; Vasoactive Intestinal Peptide

Estrogen has diverse and powerful effects in the brain, including actions on neurons, glia, and the vasculature. It is not surprising, therefore, that there are many changes in the female brain as serum estradiol levels rise and fall during the normal ovarian cycle. At times of life when estradiol levels change dramatically, such as puberty, postpartum, or menopause, there also are dramatic changes in the central nervous system. Changes that occur because of fluctuations in serum estrogen levels are potentially relevant to neurological disorders because symptoms often vary with the time of the ovarian cycle. Moreover, neurological disorders (eg, seizures and migraine) often increase in frequency in women when estradiol levels change. In this review, the contribution of 2 growth factors targeted by estrogen, the neurotrophin brain-derived neurotrophic factor (BDNF) and vascular endothelial growth factor (VEGF), will be discussed. Estrogen-sensitive response elements are present on the genes for both BDNF and VEGF, and they are potent modulators of neuronal, glial, and vascular function, making them logical candidates to mediate the multitude of effects of estrogen. In addition, BDNF induces neuropeptide Y, which has diverse actions that are relevant to estrogen action and to the same neurological disorders.

Topics: Animals; Brain-Derived Neurotrophic Factor; Estradiol; Estrogens; Female; Humans; Migraine Disorders; Nervous System Diseases; Neuropeptide Y; Vascular Endothelial Growth Factor A

To explore the cause and pathogenesis of migraine based on TCM theory and modern researches to seek for new thinking and effective drugs in treating migraine.. Ninety patients with migraine were divided into three groups, the treated group treated with Shutianing Granule (STNG) 9 g, three times a day, the control A group treated with composite Yangjiao capsule, 5 capsules each time, three times a day and the control B group treated with flunarizine hydrochloride capsule, 5 mg, once a day. The treatment lasted for 28 days to observe the degree, lasting time and frequency of pain attack, and the headache index was calculated. Transcranial Doppler examination, serum beta evoked potential (beta-EP) and neuropeptide (NPY) determination were also performed before and after treatment. In the experimental study, effect of treatment of cerebral NPY and beta-EP were tested in SD rats with chronic pain in the treated or the control groups.. In the treated group, the markedly effective rate was 56.67% and the total effective rate was 90.00%, significant difference was shown in comparison with those in the control B group (P < 0.05), but with no difference in comparison with those in the control A group. Cerebral beta-EP level was raised and plasma NPY level was lowered in all the three treated groups. Compared with the normal saline group, there was significant difference (P < 0.05 or P < 0.01).. STNG could improve the cerebrovascular function effectively, raise plasma beta-EP level, lower plasma NPY level and alleviate vascular tension in patients with migraine.

Topics: Adult; Animals; beta-Endorphin; Drugs, Chinese Herbal; Female; Humans; Male; Middle Aged; Migraine Disorders; Neuropeptide Y; Phytotherapy; Random Allocation; Rats; Rats, Sprague-Dawley

Migraine is a highly disabling health burden with multiple symptoms; however, it remains undertreated because of an inadequate understanding of its neural mechanisms. Neuropeptide Y (NPY) has been demonstrated to be involved in the modulation of pain and emotion, and may play a role in migraine pathophysiology. Changes in NPY levels have been found in patients with migraine, but whether and how these changes contribute to migraine is unknown. Therefore, the purpose of this study was to investigate the role of NPY in migraine-like phenotypes.. Here, we used intraperitoneal injection of glyceryl trinitrate (GTN, 10 mg/kg) as a migraine mouse model, which was verified by light-aversive test, von Frey test, and elevated plus maze test. We then performed whole-brain imaging with NPY-GFP mice to explore the critical regions where NPY was changed by GTN treatment. Next, we microinjected NPY into the medial habenula (MHb), and further infused Y1 or Y2 receptor agonists into the MHb, respectively, to detect the effects of NPY in GTN-induced migraine-like behaviors.. GTN effectively triggered allodynia, photophobia, and anxiety-like behaviors in mice. After that, we found a decreased level of GFP. Taken together, our data support that the NPY signaling in the MHb produces analgesic and anxiolytic effects through the Y1 receptor. These findings may provide new insights into novel therapeutic targets for the treatment of migraine.

Topics: Animals; Habenula; Hyperalgesia; Mice; Migraine Disorders; Neuropeptide Y; Photophobia; Receptors, Neuropeptide Y

Background Chronic migraine has a well-documented association with increased insulin resistance and metabolic syndrome. The hypothalamus may play a role in the progression of insulin resistance in chronic migraine through the regulation of orexigenic peptides such as neuropeptide Y. Insulin resistance may lead to increased risk of future type 2 diabetes mellitus in patients with chronic migraine, which is more likely to occur if other pathogenetic defects of type 2 diabetes mellitus, such as impaired pancreatic β-cell functions and defects in intestinal glucagon-like peptide-1 secretion after meals. We studied the relationship of fasting neuropeptide Y with insulin resistance, β-cell function, and glucagon-like peptide-1 secretion in non-obese female chronic migraine patients. We also aimed to investigate glucose-stimulated insulin and glucagon-like peptide-1 secretions as early pathogenetic mechanisms responsible for the development of carbohydrate intolerance. Methods In this cross-sectional controlled study, 83 non-obese female migraine patients of reproductive age categorized as having episodic migraine or chronic migraine were included. The control group consisted of 36 healthy females. We studied glucose-stimulated insulin and glucagon-like peptide-1 secretion during a 75 g oral glucose tolerance test. We investigated the relationship of neuropeptide Y levels with insulin resistance and β-cell insulin secretion functions. Results Fasting glucose levels were significantly higher in migraine patients. Plasma glucose and insulin levels during the oral glucose tolerance test were otherwise similar in chronic migraine, episodic migraine and controls. Patients with chronic migraine were more insulin resistant than episodic migraine or controls ( p = 0.048). Glucagon-like peptide-1 levels both at fasting and two hours after glucose intake were similar in chronic migraine, episodic migraine, and controls. Neuropeptide Y levels were higher in migraineurs. In chronic migraine, neuropeptide Y was positively correlated with fasting glucagon-like peptide-1 levels (r = 0.57, p = 0.04), but there was no correlation with insulin resistance (r = 0.49, p = 0.09) or β-cell function (r = 0.50, p = 0.07). Discussion Non-obese premenopausal female patients with chronic migraine have higher insulin resistance, but normal β-cell function is to compensate for the increased insulin demand during fasting and after glucose intake. Increased fasting neuropeptide Y levels in mig

Topics: Adult; Blood Glucose; Chronic Disease; Cross-Sectional Studies; Female; Glucagon-Like Peptide 1; Glucose; Humans; Insulin; Insulin Resistance; Migraine Disorders; Neuropeptide Y

Migraine is a painful neurologic disorder with premonitory symptomatology that can include disturbed appetite. Migraine pathophysiology involves abnormal activation of trigeminocervical complex (TCC) neurons. Neuropeptide Y (NPY) is synthesized in the brain and is involved in pain modulation. NPY receptors are present in trigeminal ganglia and trigeminal nucleus caudalis suggesting a role in migraine pathophysiology. The present study aimed to determine the effect of systemic administration of NPY on TCC neuronal activity in response to dural nociceptive trigeminovascular activation. We performed in vivo electrophysiology in anesthetized rats, administered NPY (10, 30, and 100 µg·kg), and investigated the receptors involved by studying NPY Y1 (30 µg·kg), Y2 (30 µg·kg), and Y5 receptor agonists (100·µg·kg), and NPY Y1 receptor antagonist (30 µg·kg). NPY (30 and 100 µg·kg) significantly reduced TCC neuronal firing in response to dural-evoked trigeminovascular activation, but only NPY (30 µg·kg) significantly reduced spontaneous trigeminal firing. NPY Y1 receptor agonist also significantly reduced dural-evoked and spontaneous TCC neuronal firing. NPY (10 µg·kg), NPY Y2, and Y5 receptor agonists, and the NPY Y1 receptor antagonist had no significant effects on nociceptive dural-evoked neuronal firing in the TCC or spontaneous trigeminal firing. This study demonstrates that NPY dose dependently inhibits dural-evoked trigeminal activity, through NPY Y1 receptor activation, indicating antinociceptive actions of NPY in a migraine animal model. Based on the role of NPY in appetite regulation, it is possible that disruption of the NPY system might explain changes of appetite in migraineurs.

Topics: Action Potentials; Animals; Disease Models, Animal; Male; Migraine Disorders; Neurons; Neuropeptide Y; Rats; Rats, Sprague-Dawley; Receptors, Neuropeptide Y; Trigeminal Ganglion; Trigeminal Nuclei

Cortical spreading depression (CSD) may be the underlying mechanism of migraine aura. The role of CSD in initiating a migraine headache remains to be determined, but it might involve specific changes in gene expression in the brain. To examine these changes, four episodes of CSD at 5-minute intervals were induced in the mouse brain by application of 300mM KCl, and gene expression was examined 2 hours later using cDNA array and reverse transcriptase-polymerase chain reaction. Controls consisted of groups that received anesthesia only, attachment of recording electrodes only, and application of 0.9% NaCl. Of the over 1,180 genes examined in our experiments, those consistently regulated by CSD included vasoactive peptides; the vasodilator atrial natriuretic peptide was induced by CSD, while the vasoconstrictor neuropeptide Y was downregulated. Other genes specifically regulated by CSD were involved in oxidative stress responses (major prion protein, glutathione-S-transferase-5, and apolipoprotein E). L-type calcium channel mRNA was upregulated. In summary, CSD regulates genes that are intrinsic to its propagation, that identify accompanying vascular responses as a potential source of pain, and that protect against its potential pathological consequences. We believe these observations have strong relevance to the mechanisms of migraine and its outcomes.

Topics: Anesthetics; Animals; Apolipoproteins E; Atrial Natriuretic Factor; Brain; Brain Chemistry; Calcium Channels, L-Type; Cortical Spreading Depression; Cytokines; Gene Expression; Glutathione Transferase; Mice; Migraine Disorders; Models, Animal; Neuropeptide Y; Oligonucleotide Array Sequence Analysis; Prions; Receptors, N-Methyl-D-Aspartate; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger

Evidence from animals and humans suggests that brainstem nuclei such as the raphe nuclei, the locus coeruleus (LC) and the periaqueductal grey matter (PAG), are involved in the pathophysiology of migraine. In order to understand possible neurotransmitters involved we have, by means of indirect immunocytochemistry, analysed these regions for the occurrence and distribution of calcitonin gene-related peptide (CGRP), substance P (SP), pituitary adenylate-cyclase activating peptide (PACAP) and vasoactive intestinal polypeptide (VIP). CGRP-immunoreactive (-ir) cell bodies, but no fibres, were found to occur in high numbers, constituting 80% of all nerve cell bodies in the LC. A smaller number of these nerve cell bodies (40%) in the LC proved to be PACAP-ir. The LC neurones also stored the vesicular monoamine transporter (VMAT)- and the C-terminal flanking peptide of neuropeptide Y (C-PON)-ir, illustrating their adrenergic nature. Double immunostaining revealed that all VMAT-and C-PON-containing neurones, in addition, stored CGRP. Immunoreactive cell bodies were not seen in the nucleus raphe magnus (NRM) or PAG. Numerous SP-ir nerve fibres were observed in the NRM, the LC and the PAG. Few PACAP-ir nerve fibres were detected in the PAG and few VIP-ir nerve fibres were seen in the NRM and the PAG.

Topics: Adult; Aged; Brain Stem; Calcitonin Gene-Related Peptide; Female; Humans; Locus Coeruleus; Male; Middle Aged; Migraine Disorders; Neuropeptide Y; Neuropeptides; Peptide Fragments; Periaqueductal Gray; Pituitary Adenylate Cyclase-Activating Polypeptide; Raphe Nuclei; Substance P; Vasoactive Intestinal Peptide

To test whether migraine and subarachnoid hemorrhage (SAH) are associated with increased sympathetic tone, we compared the neuropeptide Y-like (NPY-LI) and chromogranin A-like immunoreactivities (LI) of cerebrospinal fluid (CSF) from migraneurs and SAH patients with those from control subjects. Increased sympathetic tone was expected to produce higher co-release of these co-stored peptides and concordant changes in their CSF levels. In addition, we investigated a possible disturbed nitric oxide homeostasis by measuring CSF nitrites (NO). More than 70% of CSF NPY-LI corresponded to the chromatographic peak (HPLC) for the intact molecule in all three groups. Migraneurs had 64% higher CSF NPY-LI, but no significant difference in CSF chromogranin A-LI, as compared to controls. In contrast, SAH patients had 74% less CSF chromogranin A-LI and a trend to lower NPY-LI, as compared to controls. No differences in CSF NO were detected among groups. These results argue against an increased sympathetic tone in patients with either migraine or SAH, and suggest that the higher CSF NPY-LI of migraneurs probably originates from central neurons. Furthermore, our findings in SAH patients argue in favor of a decreased sympathetic tone; this could be a homeostatic response to counterbalance vasoconstriction mediated by other mechanisms.

Topics: Adult; Biomarkers; Cerebrospinal Fluid Proteins; Chromogranin A; Chromogranins; Female; Humans; Male; Middle Aged; Migraine Disorders; Nerve Tissue Proteins; Neurons; Neuropeptide Y; Nitric Oxide; Nitrites; Prospective Studies; Subarachnoid Hemorrhage; Sympathetic Nervous System; Vasomotor System

In eight patients carotid angiography was required for evaluation of transient neurological attacks. Cerebral blood flow results, angiography and clinical observations subsequently suggested the diagnosis of migraine. We measured plasma concentrations of substance P(SP), neuropeptide Y (NPY), calcitonin gene-related peptide (CGRP) and vasoactive intestinal peptide (VIP) in repeated blood samples obtained from the carotid artery and the internal jugular vein in conjunction with cerebral angiography followed by 4 to 6 repeated recordings of regional cerebral blood flow (rCBF) with the intracarotid Xenon-133 injection technique. This technique is known to induce attacks of migraine with aura in many sufferers. Four patients developed aura symptoms. In three this was succeeded by throbbing headache. Typical, migraine-related, focal hypoperfusion occurred in conjunction with the aura symptoms. The remaining four patients had no symptoms or rCBF changes. There were no systematic or statistically significant changes over time in arterial-venous plasma concentrations or in the release rates of any of the peptides. All migraineurs had an overall elevated mean CGRP value compared to control values from the literature. The overall plasma levels of the potent vasoconstrictor NPY were higher (p < 0.10) in the group that developed symptoms and rCBF changes (136 pmol/l) than in the non-symptomatic group (97 pmol/l). The difference in NPY levels could perhaps be associated with the focal rCBF decrease seen in the attack group.

Topics: Adult; Calcitonin; Calcitonin Gene-Related Peptide; Carotid Artery, Internal; Cerebral Angiography; Cerebrovascular Circulation; Female; Hemiplegia; Humans; Ischemic Attack, Transient; Jugular Veins; Male; Middle Aged; Migraine Disorders; Neuropeptide Y; Neuropeptides; Paresthesia; Radionuclide Imaging; Substance P; Vasoactive Intestinal Peptide; Vision Disorders; Xenon Radioisotopes

Neuropeptide Y (NPY) is widely distributed throughout sympathetic nerve endings where it is co-stored and co-secreted with noradrenaline. It is considered a marker of noradrenergic function. To determine the role of NPY in the pathogenesis of juvenile headache, we determined its plasma levels in two groups of young migraine patients (with and without aura), in a group of episodic tension-type headache patients and in a group of age and sex-matched healthy subjects. Significantly lower plasma levels of NPY were evident in the migraine patients with aura (P < 0.001) and, to a lesser extent, in the migraine patients without aura (P < 0.02), both assessed in the interictal period, with respect to the control group. Plasma NPY levels tended to significantly increase during attacks in migraine patients with aura (P < 0.0009). A less evident, though significant increase was also present during attacks in migraine patients without aura (P < 0.02). No significant variations were observed between headache-free periods and attacks in tension-type headache patients. Reduced NPY levels in the interictal period can be considered further evidence of the derangement of the sympathetic function in the course of migraine, particularly that with aura. The increase in NPY levels during migraine attacks could be an expression of sympathetic activation, even though the functional status of this system is less efficient.

Topics: Adolescent; Child; Female; Headache; Humans; Male; Migraine Disorders; Muscle Contraction; Neuropeptide Y; Sensation Disorders

The somatostatin-like (SLI), the neuropeptide Y-like (NPY-LI), and the beta-endorphin-like (BE-LI) immunoreactivities of cerebrospinal fluid (CSF) obtained by suboccipital puncture, or plasma from patients suffering from common migraine or other neuropsychiatric disorders were analysed. The SLI concentration was tendentiously decreased in the migraine patients during the attack-free period compared to that of a 'mixed neuropsychiatric group'. During the migraine attack the level of SLI was further decreased. Similar alteration was found in the CSF BE-LI, while the BE-LI in the plasma showed only a tendentious decrease in common migraine patients. The NPY-LI did not change during the attack period in the CSF or plasma. These findings may indicate the possible role of somatostatin in the pathogenesis of common migraine, and support earlier observations that beta-endorphin is involved in the development in this disorder.

Topics: Adult; beta-Endorphin; Female; Humans; Male; Middle Aged; Migraine Disorders; Neuropeptide Y; Radioimmunoassay; Somatostatin

The innervation of the cranial vessels by the trigeminal nerve, the trigeminovascular system, has recently been the subject of study in view of its possible role in the mediation of some aspects of migraine. Since stimulation of the trigeminal ganglion in humans leads to facial pain and flushing and associated release of powerful neuropeptide vasodilator substances, their local release into the extracerebral circulation of humans was determined in patients who had either common or classic migraine. Venous blood was sampled from both the external jugular and cubital fossa ipsilateral to the side of headache. Plasma levels of neuropeptide Y, vasoactive intestinal polypeptide, substance P, and calcitonin gene-related peptide were determined using sensitive radioimmunoassays for each peptide, and values for the cubital fossa and external jugular and a control population were compared. A substantial elevation of the calcitonin gene-related peptide level in the external jugular but not the cubital fossa blood was seen in both classic and common migraine. The increase seen in classic migraine was greater than that seen with common migraine. The other peptides measured were unaltered. This finding may have importance in the pathophysiology of migraine.

Topics: Adult; Calcitonin Gene-Related Peptide; Cerebrovascular Circulation; Elbow; Female; Humans; Jugular Veins; Male; Middle Aged; Migraine Disorders; Neuropeptide Y; Neuropeptides; Substance P; Trigeminal Ganglion; Vasoactive Intestinal Peptide; Vasodilation

Topics: Adrenergic Fibers; Calcitonin Gene-Related Peptide; Cerebral Arteries; Cerebrovascular Circulation; Cholecystokinin; Cholinergic Fibers; Gastrin-Releasing Peptide; Histamine; Humans; Migraine Disorders; Muscle, Smooth, Vascular; Neuropeptide Y; Neuropeptides; Neurotransmitter Agents; Peptides; Serotonin; Substance P; Vasoactive Intestinal Peptide