vasoactive-intestinal-peptide and Urticaria

Cutaneous wheal and flare responses to increasing concentrations of calcitonin gene-related peptide, substance P, neurokinin A, vasoactive intestinal polypeptide (VIP), compound 48/80, and phosphate-buffered saline were measured in 10 patients with chronic idiopathic urticaria and 10 healthy controls. A significant increase in VIP-induced wheal, but not flare or cutaneous blood flow, was seen in urticarial patients compared with controls (p less than 0.001). No significant differences in responses to other tested compounds were found between these groups. These data point to an increased sensitivity of microvasculature to VIP in patients with chronic idiopathic urticaria.

Topics: Adult; Calcitonin Gene-Related Peptide; Chronic Disease; Female; Humans; Intradermal Tests; Male; Microcirculation; Middle Aged; Neurokinin A; Skin; Substance P; Urticaria; Vasoactive Intestinal Peptide

Wheal reactions to intradermally injected neuropeptides, such as substance P (SP) and vasoactive intestinal peptide, are significantly larger and longer lasting in patients with chronic urticaria (CU) than in nonatopic control (NC) subjects. Mas-related gene X2 (MrgX2) has been identified as a receptor for basic neuropeptides, such as SP and vasoactive intestinal peptide. Mast cell (MC) responsiveness to eosinophil mediators contributes to the late-phase reaction of allergy.. We sought to compare the frequency of MrgX2 expression in skin MCs from patients with CU and NC subjects and to identify the receptor for basic eosinophil granule proteins on human skin MCs.. MrgX2 expression was investigated by using immunofluorescence in skin tissues from NC subjects and patients with severe CU and on skin-derived cultured MCs. MrgX2 expression in human MCs was reduced by using a lentiviral small hairpin RNA silencing technique. Ca(2+) influx was measured in CHO cells transfected with MrgX2 in response to eosinophil granule proteins. Histamine and prostaglandin D2 levels were measured by using enzyme immunoassays.. The number of MrgX2(+) skin MCs and the percentage of MrgX2(+) MCs in all MCs in patients with CU were significantly greater than those in NC subjects. Eosinophil infiltration in urticarial lesions was observed in 7 of 9 patients with CU. SP, major basic protein, and eosinophil peroxidase, but not eosinophil-derived neurotoxin, induced histamine release from human skin MCs through MrgX2.. MrgX2 might be a new target molecule for the treatment of wheal reactions in patients with severe CU.

Topics: Adult; Aged; Aged, 80 and over; Cells, Cultured; Chronic Disease; Eosinophil Granule Proteins; Female; Humans; Male; Mast Cells; Middle Aged; Molecular Targeted Therapy; Nerve Tissue Proteins; Protein Binding; Receptors, G-Protein-Coupled; Receptors, Neuropeptide; Skin; Skin Tests; Substance P; Up-Regulation; Urticaria; Vasoactive Intestinal Peptide; Young Adult

H1-receptor inhibiting drugs, namely loratadine and cetirizine, were frequently used in treatment of chronic urticaria. Urticarial weal and flare reactions, a neurogenic reflex due to neuropeptides, were reported to be more effectively inhibited by cetirizine than loratadine. The aim of this study was to determine and compare the effects of systemic loratadine and cetirizine treatments on serum levels of selected neuropeptides in chronic urticaria. Treatment groups of either systemic loratadine or cetirizine (10 mg/d), consisting of 16 and 22 patients, respectively, were included. Serum levels of stem cell factor (SCF), neuropeptide Y (NPY), calcitonin gene-related peptide (CGRP), nerve growth factor (NGF), vasoactive intestinal peptide (VIP), and substance P (SP) were detected before and after one week of treatment with antihistamines. Serum NPY and VIP levels were significantly decreased when compared before and after treatment with antihistamines (P < 0.001 and P < 0.01, respectively). SCF and NGF values were also decreased after antihistamine treatment (P < 0.05). Post-treatment levels of CGRP were significantly higher compared with pretreatment values, while no significant difference was detected between pre and post treatment levels of SP. Cetirizine was significantly more effective than loratadine on lowering serum levels of SCF among the other neuropeptides. Systemic loratadine and cetirizine treatments in patients with chronic urticaria precisely caused variations in serum levels of neuropeptides. The predominant effect of cetirizine compared to loratadine on reducing serum SCF levels might be explained with anti-inflammatory properties of cetirizine.

Topics: Adolescent; Adult; Calcitonin Gene-Related Peptide; Cetirizine; Chronic Disease; Female; Histamine H1 Antagonists, Non-Sedating; Humans; Loratadine; Male; Middle Aged; Nerve Growth Factor; Neuropeptide Y; Neuropeptides; Stem Cell Factor; Substance P; Urticaria; Vasoactive Intestinal Peptide; Young Adult

Pituitary adenylate cyclase-activating peptide (PACAP) is an important neuropeptide and immunomodulator in various tissues. Although this peptide and its receptors (ie, VPAC1R, VPAC2R, and PAC1R) are expressed in human skin, their biological roles are unknown. Therefore, we tested whether PACAP regulates vascular responses in human skin in vivo. When injected intravenously, PACAP induced a significant, concentration-dependent vascular response (ie, flush, erythema, edema) and mediated a significant and concentration-dependent increase in intrarectal body temperature that peaked at 2.7°C. Topical application of PACAP induced marked concentration-dependent edema. Immunohistochemistry revealed a close association of PACAP-immunoreactive nerve fibers with mast cells and dermal blood vessels. VPAC1R was expressed by dermal endothelial cells, CD4+ and CD8+ T cells, mast cells, and keratinocytes, whereas VPAC2R was expressed only in keratinocytes. VPAC1R protein and mRNA were also detected in human dermal microvascular endothelial cells. The PACAP-induced change in cAMP production in these cells demonstrated VPAC1R to be functional. PACAP treatment of organ-cultured human skin strongly increased the number of CD31+ vessel cross-sections. Taken together, these results suggest that PACAP directly induces vascular responses that may be associated with neurogenic inflammation, indicating for the first time that PACAP may be a crucial vascular regulator in human skin in vivo. Antagonists to PACAP function may be beneficial for the treatment of inflammatory skin diseases with a neurogenic component.

Topics: Adult; Humans; Male; Pituitary Adenylate Cyclase-Activating Polypeptide; Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide, Type I; Receptors, Vasoactive Intestinal Peptide, Type II; Receptors, Vasoactive Intestinal Polypeptide, Type I; Regional Blood Flow; Skin; Tissue Culture Techniques; Urticaria; Vasoactive Intestinal Peptide; Young Adult

Immediate hypersensitivity responses, as acute urticaria, produce a release of neuropeptides by nerve endings, which present specificity of recognition by mast cells, basophils and other target cells. We have measured vasoactive intestinal peptide (VIP), somatostatin, bombesin, neurotensin and beta-endorphin by radioimmunoassay in plasma extracts of 20 patients with acute idiopathic urticaria and of 20 healthy subjects. VIP- and beta-endorphin-like immunoreactivities were found to be significantly decreased with respect to controls (p less than 0.001 and p less than 0.01, respectively). On the contrary, somatostatin- and bombesin-like immunoreactivities were significantly increased (p less than 0.001 and p less than 0.05, respectively). These findings could be a reflection in blood of a raised release of somatostatin and bombesin by nerve endings in the urticaria process. Moreover, the decreased plasma levels of VIP- and beta-endorphin-like immunoreactivities could be explained by a raised specific metabolism of these peptides in the urticaria process.

Topics: Adult; beta-Endorphin; Bombesin; Female; Humans; Male; Middle Aged; Neuropeptides; Somatostatin; Urticaria; Vasoactive Intestinal Peptide

Substance P (SP), calcitonin gene-related peptide (CGRP), and vasoactive intestinal peptide (VIP) were assayed in lesions and normal skin of patients with dermographism and cold urticaria utilizing suction-induced blisters. There was no difference in SP and VIP concentrations between challenged and control skin of urticaria patients. On the whole, however, the concentration of both neuropeptides, and VIP in particular, was higher in the urticaria patients than in control subjects. CGRP levels were not increased. SP and VIP in blood samples from veins draining challenged skin areas were below the detection limit. It is concluded that SP and VIP may potentiate histamine in wheal formation and thus contribute to the increased reactivity of the skin to trauma and temperature changes in patients with physical urticaria.

Topics: Adult; Aged; Aged, 80 and over; Blister; Calcitonin Gene-Related Peptide; Cold Temperature; Female; Humans; Male; Middle Aged; Neuropeptides; Physical Stimulation; Radioimmunoassay; Skin; Substance P; Urticaria; Vasoactive Intestinal Peptide