SEARCH · Search PubMed

Results for “Injections, Intradermal”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 811 records · Page 45Linked to original sources

PubMed1960

Suppression of experimental "allergic" encephalomyelitis in guinea pigs by encephalitogenic proteins extracted from homologous brain.

The intradermal injection of aqueous solutions of certain homologous neural proteins will suppress the encephalomyelitis which is induced in guinea pigs by the previous injection of whole homologous brain with Freund's adjuvants. These neural proteins extracted by dilute acid from defatted guinea pig brain are themselves highly encephalitogenic when injected with adjuvants, but the specificity of this suppression for encephalitogenic as compared to non-encephalitogenic extracts remains to be proven. Suppression is probably not due to a non-specific stress reaction, as indicated by the absence of suppression by intradermal injections of alcohol and by statistically insignificant and inconstant effects of similar injections of tuberculin.

Adjuvants, Immunologic↗

PubMed2002

Mast cell chymase regulates dermal mast cell number in mice.

Chymase inhibitor reduced the increase in the number of dermal mast cells in 2,4-dinitrofluorobenzene-induced dermatitis in a dose-dependent manner. Intradermal injection of human chymase to mouse ear significantly increased histamine content, the marker for mast cell number in the skin. These results suggest that chymase released by mast cells may participate in local mast cell accumulation in a positive feedback fashion. Immunohistochemical analysis revealed that the intradermal injection of chymase reduces expression of stem cell factor (SCF) on surface of the skin keratinocytes. In addition, incubation of human keratinocytes with chymase in vitro resulted in release of SCF into the culture medium. Since soluble SCF is thought to regulate mast cell number, the chymase-induced mast cell accumulation may occur via the ability of chymase to process membrane-bound SCF on the epidermal keratinocytes.

Animals↗

PubMed2006

Activation of protein kinase B/Akt in the periphery contributes to pain behavior induced by capsaicin in rats.

Protein kinase B (PKB/Akt) is a member of the second-messenger regulated subfamily of protein kinases. It is implicated in signaling downstream of growth factors, insulin receptor tyrosine kinases and phosphoinositide 3-kinase (PI3K). Current studies indicate that nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF) and PI3K help mediate inflammatory hyperalgesia. However, little is known about the role of PKB/Akt in the nociceptive system. In this study, we investigated whether PKB/Akt in primary sensory neurons is activated after noxious stimulation and contributes to pain behavior induced in rats by capsaicin. We demonstrated that phospho-PKB/Akt (p-PKB/Akt) is increased in dorsal root ganglia (DRG) at 5 min after intradermal injection of capsaicin. p-PKB/Akt is distributed predominantly in small- and medium-sized DRG cells. After capsaicin injection, p-PKB/Akt (473) is colocalized with isotectin-B4 (IB4), tyrosine kinase A (TrkA), and calcitonin gene-related peptide (CGRP). Furthermore, most transient receptor potential vanilloid type 1 (TRPV1) positive DRG neurons double label for p-PKB/Akt. Behavioral experiments show that intradermal injection of a PI3K (upstream of PKB/Akt) inhibitor, wortmannin, dose-dependently inhibits the changes in exploratory behavior evoked by capsaicin injection. The PKB/Akt inhibitor, Akt inhibitor IV, has the same effect. The results suggest that the PKB/Akt signaling pathway in the periphery is activated by noxious stimulation and contributes to pain behavior.

Animals↗

PubMed2005

A randomized, blinded, parallel group, placebo controlled pilot study evaluating the effect of PVAC treatment in patients with diffuse systemic sclerosis.

OBJECTIVE: Systemic sclerosis (SSc) is a disorder characterized by progressive thickening of the skin; there is no effective therapy. PVAC, a potential therapeutic agent derived from delipidated, deglycolipidated Mycobacterium vaccae, has shown effects on cutaneous disease in animal models of SSc. We evaluated the safety and possible biologic effect of intradermal injections of PVAC in patients with diffuse SSc. METHODS: Eighteen patients enrolled in this double blind, placebo controlled, randomized, 24 week pilot study. All patients met criteria for diffuse SSc without evidence of significant renal dysfunction, pulmonary fibrosis, pulmonary hypertension, or congestive heart failure. Patients received 8 intradermal injections of 15 microg PVAC, 50 microg PVAC, or placebo at 3 week intervals. The primary efficacy endpoint was the change in Modified Rodnan Skin Score (MRSS) at Week 24. Each of the active drug arms was compared to placebo. RESULTS: Baseline demographic and disease characteristics were similar across the 3 treatment groups. The median age was 48 years and 14 of 18 (78%) patients were female. The regimens were well tolerated with no reported serious adverse events; however, grade 1 or 2 injection site reactions occurred in the majority of patients receiving PVAC. The MRSS improved by 20.6% in the 15 microg PVAC arm, while it worsened by 29.8% in the placebo arm and by 16.7% in the 50 microg arm. Change in physician and patient global assessments followed similar trends. CONCLUSION: In this pilot study, use of PVAC in patients with SSc appeared safe and was associated with a trend toward improved skin scores in the 15 microg treatment group. Additional evaluation of this therapeutic approach is warranted.

Adult↗

PubMed2005

Secondary heat hyperalgesia detected by radiant heat stimuli in humans: evaluation of stimulus intensity and duration.

Diverging observations on secondary hyperalgesia to heat stimuli have been reported in the literature. No studies have investigated the importance of heat stimulus intensity and duration for the assessment of secondary heat hyperalgesia. The present study was designed to investigate systematically (1) if pain sensitivity to radiant heat stimuli (focused Xenon light) is altered in the area of secondary punctuate hyperalgesia induced by intradermal injection of capsaicin and (2) if heat stimulus duration and intensity had an influence on the ability to detect secondary heat hyperalgesia. Pain ratings to radiant heat stimuli from a focused xenon lamp were assessed within the area of secondary punctuate hyperalgesia in fifteen volunteers before and after intradermal injection of capsaicin. The stimulus conditions were systematically varied between three intensity levels (0.8, 1.0 and 1.2 x heat pain threshold (PT)) and four duration steps (200, 350, 500 and 750 ms). The present study shows that long duration (350-750 ms) and low intensity (0.8 and 1.0 x PT) radiant heat stimuli were adequate to detect secondary heat hyperalgesia.

Adult↗

PubMed1991

Abnormal cutaneous response to mitogens and a contact allergen in dogs with atopic dermatitis.

Antigen specific and nonspecific T-lymphocyte activity was evaluated in normal dogs and in dogs with atopic dermatitis by measuring the increase in skin thickness after application of the contact allergen dinitrochlorobenzene and after intradermal injection of the mitogens phytohemagglutinin and concanavalin A. The atopic dogs had a significantly reduced response to the contact allergen (P less than or equal to 0.001) but a significantly increased response to the mitogens (P less than or equal to 0.001). The atopic and normal dogs responded similarly to intradermally injected histamine. The response of dogs with non-atopic skin conditions to the cutaneous mitogen test was like that of normal dogs. Pre-existing dermatitis does not apparently influence cutaneous response to mitogens in dogs. The cutaneous response of atopics during treatment with corticosteroids is not different from normal controls. These results suggest a role for altered cell-mediated immunity in the pathogenesis of canine atopy and that the cutaneous mitogen test may have value as a rapid screening test for the disease.

Animals↗

PubMed1952

The effect of cortisone on the Shwartzman reaction; the production of lesions resembling the dermal and generalized Shwartzman reactions by a single injection of bacterial toxin in cortisone-treated rabbits.

1. Cortisone, in a dose of 25 mg. daily and with a pretreatment period of 3 days, in rabbits weighing 1 to 1.5 kilos, did not inhibit the dermal Shwartzman reaction produced by meningococcal or S. marcescens toxin. 2. In cortisone-treated rabbits, a single intradermal injection of toxin produced a primary reaction of hemorrhage and necrosis in the skin at the injected site. This lesion resembled the Shwartzman reaction in its gross and histological appearance. 3. Like the Shwartzman reaction, the primary hemorrhagic reaction in cortisone-treated rabbits was prevented by nitrogen mustard, and the preventive effect of nitrogen mustard was partly eliminated when the femoral marrow was protected against the latter agent. 4. A single intravenous injection of meningococcal or S. marcescens toxin, in cortisone-treated rabbits, was followed by bilateral cortical necrosis of the kidneys in the majority of instances. The renal lesions, as well as hemorrhages in the lungs, spleen, liver, and gastrointestinal tract, resembled the lesions of the generalized Shwartzman reaction. Histologically, the glomerular capillaries in both types appeared to be occluded by homogeneous, eosinophilic material which showed a strongly positive Schiff reaction. 5. The renal lesion following a single injection of toxin in cortisone-treated animals, and that following two intravenous injections in the generalized Shwartzman reaction, were both completely prevented by nitrogen mustard. This effect of nitrogen mustard was inhibited when the femoral marrow was protected against the latter agent. 6. The injection of S. marcescens toxin into the skin of normal rabbits did not cause systemic symptoms, nor was it possible to provoke the generalized Shwartzman reaction by this route. In cortisone-treated rabbits, a similar intradermal injection was regularly followed by the development of bilateral cortical necrosis of the kidneys, indicating that absorption of toxin from the skin occurred in these animals. 7. Possible mechanisms to account for the observations are discussed. The authors are obliged to Professor James R. Dawson for many helpful suggestions during the course of this investigation.

Animals↗

PubMed1991

Cutaneous and basophilic sensitivity to substance P and gastrin in non-atopic versus atopic subjects.

We compared the cutaneous reaction to intradermal injection of substance P, gastrin and histamine in asymptomatic atopic subjects with a history of hay fever and/or asthma versus non-atopic healthy volunteers. We also studied in these two groups the basophilic histamine release induced by substance P and gastrin with that obtained with anti-human IgE and Con A. Intradermal injection of substance P (3-300 pM) and gastrin (3-30 pM) caused a wheal and flare reaction which was comparable in both groups of subjects. Substance P 10(-4)M caused a mean basophilic histamine release of about 15% in atopic and non-atopic subjects. Gastrin was not effective in this model. Anti-IgE and Con A-induced histamine release was significantly higher in atopic than in non-atopic volunteers.

Adult↗

PubMedDate not supplied

Autologous fibroblasts for treatment of facial rhytids and dermal depressions. A pilot study.

OBJECTIVE: To assess effectiveness of intradermal injections of autologous fibroblasts for the treatment of facial rhytids and dermal depressions. DESIGN: Six-month prospective pilot study. Photographs and silicone molds were taken of a prominent rhytid or dermal depression from each patient prior to treatment and at 6 months after treatment. SETTING: Specialty clinic in academic medical center. PATIENTS: Ten adults (age range, 24-69 years) who each exhibited a prominent rhytid or depressed facial scar. INTERVENTION: A 3-mm postauricular skin biopsy specimen from each participant was sent to Isolagen Technologies, Inc, laboratories, where a fibroblast cell line was developed. Three injection sessions were performed at 2-week intervals; target areas were the study site as well as behind the ear. MAIN OUTCOME MEASURES: Subjective improvement scores were obtained by each patient and 2 clinicians at every follow-up visit. Skin surface topographical features were evaluated with optical profilometry by comparing silicone molds before and after injection. Histological analysis was performed on a biopsy specimen of the postauricular injection site. RESULTS: Nine of 10 patients noted a 60% to 100% improvement with the treatment; clinicians made similar observations. Size reduction of 10% up to 85% of the study site was demonstrated by optical profilometry for every patient. Microscopically, there was evidence of increased thickness and density of dermal-layer collagen. CONCLUSIONS: Intradermal injection of autologous fibroblasts may be an effective treatment option for facial rhytids and depressed scars.

Acne Vulgaris↗

PubMed2003

Areolar-cutaneous "junction" injections to augment sentinel node count activity.

PURPOSE: The authors report on a modified lymphoscintigraphy protocol for increasing activity in the sentinel node (SN) through a specific technique (LymphoBoost). It consists of an areolar-cutaneous "junction" injection, using a very shallow, high-volume, high-specific-activity injection of 100% filtered Tc-99m sulfur colloid, as an adjunct to their standard protocol. MATERIALS AND METHODS: Results from a previously optimized protocol (group 1, n = 28) were compared with those from their new protocol (group 2, n = 85), which consisted of two sets of consecutively applied (within 12 to 20 minutes) injections: group 2A composed of perilesional and intradermal injections (similar to the previous group 1) followed by group 2B LymphoBoost injections within 12 to 20 minutes in the same patients. Regions of interest were drawn around the SN and the injection sites (IS) at the end of the studies to calculate the end-of-study SN:IS ratio for both group 1 and group 2 studies. The SN:IS ratio is generally independent of dose and is a measurement of the "efficiency" of getting activity from the IS to the SN. RESULTS: The mean SN:IS ratio in group 2 was 3.34 times greater than that in group 1 studies (P < 0.0005). The median SN:IS ratio was 3.53 times greater in the group 2 studies. Many cases showed a dramatic increase in SN counts before the LymphoBoost injection was even completed, with more than 5% of injected activity reaching nodes at the end of the study in some patients. Multiple different lymphatic pathways were noted, but all led to the same node(s). No significant disagreement between group 2A and group 2B results was noted. CONCLUSIONS: Areolar-cutaneous junction injections, performed under these conditions, augment SN activity dramatically in most patients. Hotter nodes provide several benefits, especially when next-day surgery is contemplated, and should also reduce the extent of dissection needed to remove the sentinel node.

Breast↗

PubMed2006

The contribution of alpha-1 and alpha-2 adrenoceptors in peripheral imidazoline and adrenoceptor agonist-induced nociception.

We evaluated the effects of activation of peripheral adrenoceptors (AR) and imidazoline receptors on nociception and the contribution of alpha-1 and alpha-2 AR receptors in agonist-induced nociception by using the tail-flick test in mice. Clonidine (alpha-2 AR agonist), agmatine (imidazoline receptor and alpha-2 AR agonist), noradrenaline (mixed alpha-1 and alpha-2 AR agonist), phenylephrine (alpha-1 AR agonist), or 0.9% saline was given by intradermal injection (10 microL) into the tail. The intradermal injection of clonidine (1, 3, and 10 microg) and agmatine (3, 30, and 50 microg) produced dose-dependent antinociception, whereas noradrenaline (1, 10, and 30 microg) and phenylephrine (1, 10 and 30 microg) produced dose-dependent thermal hyperalgesia. Clonidine (10 microg) and agmatine (50 microg)-induced peripheral antinociception were antagonized by pretreatment with yohimbine (2.5 mg/kg IP), a selective alpha-2 AR antagonist, but not by prazosin (1 mg/kg IP), a selective alpha-1 AR antagonist. Noradrenaline (30 microg) and phenylephrine (30 mug)-induced thermal hyperalgesia were antagonized by prazosin (1 mg/kg IP) but not by yohimbine (2.5 mg/kg IP). Our results suggest that local thermal hyperalgesic effects of noradrenaline and phenylephrine are linked to alpha-1 AR and the peripheral antinociceptive action of clonidine and agmatine are linked to alpha-2 AR.

Adrenergic alpha-Agonists↗

PubMed2004

Immunisation against plague by transcutaneous and intradermal application of subunit antigens.

We have investigated immunological responses in BALB/c mice following transcutaneous (TC) delivery of fraction 1 (F1) and V subunits from Yersinia pestis in conjunction with an enterotoxin-derived adjuvant (cholera toxin, CT). It was found that two or more TC applications of F1 and V subunits (admixed with cholera toxin) served to elicit significant levels of anti-F1 and V antibodies in the serum of immunised mice. IL-6 secretion from cultured splenocytes derived from immunised mice indicated that a single TC application of F1 and V subunits (admixed with cholera toxin) conferred a cell-mediated response. As compared with intranasal or direct intradermal injection of F1 and V, the numbers of F1/V-specific antibody-forming cells in the spleens of animals immunised by TC application of F1 and V (admixed with CT) was relatively low. It was noted that TC application of F1 and V admixed with CT was very effective for priming responses that were boosted by intranasal or intradermal routes. Similarly, it was found that TC application of F1 and V admixed with CT could be used to efficiently boost pre-existing responses engendered by intradermal injection or intranasal instillation of F1 and V. In order to assess if TC application of F1 and V admixed with CT could protect experimental animals from plague, immunised mice were injected with a virulent strain of Y. pestis. It was found that two TC applications of F1 and V admixed with CT conferred only limited protection against 10(2) MLDs. However, three TC applications of F1 and V admixed with CT conferred solid protection against 10(2) MLDs. Hence we have shown, for the first time, that TC application of F1 and V admixed with CT can protect animals against challenge with a virulent strain of plague causing bacteria. These data suggest that transcutaneous immunisation may be a simple and non-invasive method for immunising individuals against plague.

Adjuvants, Immunologic↗

PubMed2001

Capsaicin responses in heat-sensitive and heat-insensitive A-fiber nociceptors.

The recently cloned vanilloid receptor (VR1) is postulated to account for heat and capsaicin sensitivity in unmyelinated afferents. We sought to determine whether heat and capsaicin sensitivity also coexist in myelinated nociceptive afferents. Action potential (AP) activity was recorded from single A-fiber nociceptors that innervated the hairy skin in monkey. Before intradermal injection of capsaicin (10 microg/10 microl) into the receptive field, nociceptors were classified as heat-sensitive (threshold, </=53 degrees C, 1 sec) or heat-insensitive afferents and as mechanically sensitive (von Frey threshold, <6 bar) or mechanically insensitive afferents. All heat-sensitive afferents (n = 16) were insensitive to mechanical stimuli but responded to the intradermal injection of capsaicin (69 +/- 7 APs in 10 min). Responsiveness to mechanical stimuli, thermal stimuli, and capsaicin varied in their receptive fields; the majority of receptive field sites (24 of 36) were responsive to only one or two stimulus modalities, whereas only eight sites responded to all three modalities. For most heat-insensitive afferents, the activity induced by the capsaicin injection did not exceed the activity induced by needle insertion alone. However, the largest response to capsaicin (314 +/- 98 APs in 10 min) was observed for five afferents that were insensitive to heat as well as mechanical stimuli and therefore may be classified as cutaneous chemoreceptors. These results suggest that A-fiber nociceptors play a role in the pain and hyperalgesia associated with capsaicin injection. Our finding that a subgroup of capsaicin-sensitive A-fiber nociceptors are insensitive to heat predicts the existence of heat-insensitive capsaicin receptors.

Action Potentials↗

PubMed1988

Actions of platelet activating factor (PAF) homologues and their combinations on neutrophil chemokinesis and cutaneous inflammatory responses in man.

The inflammatory actions of synthetic C16:0 and C18:0 platelet activating factor (PAF) homologues, both alone and in combination, have been compared in an in vitro human neutrophil chemokinesis assay and by intradermal injection in human skin. In the chemokinesis assay, the maximum distance moved by neutrophils in the presence of C18:0 PAF was significantly greater than that seen with the C16:0 compound. A mixture of C16:0 and C18:0 PAFs in a ratio of 1:9 appeared to be more active than in a ratio of 3:1. Intradermal injection of the C16:0 and C18:0 PAF homologues induced dose-dependent increases in weal volume and flare area responses which were not significantly different. Combination of these phospholipids in a ratio of 3:1 or 1:9 of C16:0:C18:0 did not significantly alter the dose response curves. Thus, changes in the chain length of the alkyl substituent of synthetic PAF homologues and combination of these homologues, in ratios found in vivo or formed by leukocytes in vitro, did not alter the cutaneous inflammatory responses to PAF in man. The C18:0 homologue was, however, more active as a human neutrophil chemoattractant in vitro.

Chemotaxis, Leukocyte↗

PubMed1983

Role of antigen structure in the regulation of IgE isotype expression.

Tobacco glycoprotein (TGP) is a glycoprotein containing rutin-like polyphenol groups that is purified from cured tobacco leaves and can be detected in condensates of tobacco smoke. One-third of normal humans have been shown to manifest immediate, IgE-mediated, wheal and flare reactions to an intradermal injection of TGP. Rutin-like moieties are also found in a wide variety of vegetable foods. The possible importance of sensitivity to TGP in the pathogenesis of the vascular and pulmonary complications of tobacco smoking has stimulated us to study the immune response of mice to TGP and the role of rutin groups in influencing isotype expression. A series of three intradermal injections of TGP elicits a long-lasting IgE antibody response in mice. However, no hemagglutinating antibodies are produced. Similarly, immunization with a rutin derivative of bovine serum albumin stimulates IgE antibodies to bovine serum albumin but little hemagglutinating antibodies. In contrast, mice injected in the same manner with bovine serum albumin produce both IgE and hemagglutinating antibodies. Thus, the rutin moiety is implicated as exerting a regulatory effect on isotype expression by suppressing the production of serum antibodies of isotypes other than IgE. The immunization procedure employed (which involves an initial injection of 100 micrograms of antigen in phosphate-buffered saline, followed, at monthly intervals, by two intradermal injections of 100 micrograms of antigen precipitated on alum) apparently fails to stimulate the normal "down-regulation" of the IgE response so that a persisting high-titered response is obtained.

Animals↗

PubMed2006

Increased interleukin-1beta mRNA expression in skin biopsies of horses with Culicoides hypersensitivity following challenge with Culicoides nubeculosus extract.

Interleukin-1beta (IL-1beta) is a primary cytokine of the skin that has a pivotal role in keratinocyte differentiation, epidermal wound healing and host defense. Pathological increase of cutaneous IL-1beta is associated with edema formation, epidermal hyperproliferation and atopic dermatitis in humans. However, in horses the role of cutaneous IL-1beta in edema formation and allergic skin disease has not been characterised so far. Particularly in Culicoides hypersensitivity (CHS), intradermal injection of Culicoides extract may be associated with enhanced transcription of local IL-1beta. To examine the mRNA expression of IL-1beta and its receptor antagonist IL-1RA in the skin of horses, biopsy specimens of horses affected and non-affected by CHS prior and following intradermal challenge with a commercial C. nubeculosus extract were examined. Our hypothesis was that cutaneous IL-1beta mRNA was significantly upregulated in horses with CHS in response to Culicoides allergen. Biopsies were taken from sites prior to and 4 h following intradermal challenge with C. nubeculosus extract. In order to obtain reliable data, real time PCR was performed and genes of interest were normalized using three different housekeeping genes, beta-actin, GAPDH, beta-2-microglobulin. No significant difference was detected in non-challenged cutaneous IL-1beta mRNA and IL-1RA mRNA levels between CHS affected and non-affected horses. Intradermal injection of C. nubeculosus extract resulted in local upregulation of IL-1beta mRNA both in horses with typical history, characteristic clinical signs for CHS and a positive intradermal skin test (IDT), and non-affected horses with a negative IDT. However, the difference in prior and post challenged site IL-1beta mRNA levels only reached statistical significance in the affected horses (p=0.01 versus 0.7). In contrast, IL-1RA mRNA levels did not demonstrate any modification following intradermal injection with C. nubeculosus in either group. In contrast to human atopic dermatitis, clinically normal skin of horses affected by CHS is not characterized by increased maintenance levels of IL-1beta mRNA. C. nubeculosus stimulates local IL-1beta transcription in all horses independent from disease, but the extent of upregulation from basal levels only reaches statistical significance in horses affected by CHS and active stage of disease.

Animals↗

PubMed1996

Comparison of the actions of kallidin and bradykinin in the skin of normal and psoriatic subjects.

With the recent development of selective drugs acting on the kinin system and the identification of a kallikrein-like enzyme from psoriatic blister fluid, there is now much interest in the possible role of kinins in psoriasis. We have examined the time-course of the inflammatory (weal and flare) responses to intradermal kallidin (lysbradykinin) and bradykinin in normal volunteers, and have compared the dose-response effect of these agents in normal volunteers and patients with psoriasis. Initially, normal subjects (n = 5) received coded intradermal injections of 50 microliters normal saline containing kallidin or bradykinin (0.1, 0.5, 1.0 and 5.0 micrograms). Weal volume, weal area and flare area were calculated at 5, 15, 30 and 60 min by measuring two perpendicular diameters and change in skinfold thickness. Weal and flare measurements were subsequently made at 15 and 5 min, respectively. Patients with psoriasis (n = 9) and normal subjects (n = 10) were given intradermal injections of kallidin (0.1 and 1.0 microgram) and bradykinin (0.1, 0.5 and 1.0 microgram) in clinically normal forearm skin, using histamine and normal saline as controls. The dose-response effects of kallidin on weal and flare responses in human skin were established in the study and compared with those of bradykinin. There was wide inter-individual variability for both agents and, although mean responses to the highest doses of kallidin and bradykinin were decreased in psoriatic skin, no significant differences were found between the psoriatic and normal group for kallidin, bradykinin or histamine. Hence, there do not appear to be any obvious altered vascular responses to kallidin or bradykinin in patients with psoriasis, despite the fact that kinins may be generated in psoriatic tissue.

Adult↗

PubMed1998

Effects of H1 antagonists on the cutaneous vascular response to histamine and bradykinin: a study using scanning laser Doppler imaging.

Histamine plays an important part in the cutaneous weal and flare response which underlies many allergic skin conditions. It has a direct effect on the local vasculature to promote vasodilatation and increase microvascular permeability and may also initiate the more widely spread neurogenic flare. Quantification of these responses and studies of the mediator mechanisms underlying them have been limited by the lack of appropriate techniques to investigate them. To address this we have used two relatively new techniques, scanning laser Doppler imaging (LDI) and dermal microdialysis to measure changes in skin blood flow and the release of histamine within the weal and flare, following intradermal injection of histamine or bradykinin. These measurements have been made both in the absence and presence of the H1 receptor blockers cetirizine and loratadine. Scanning LDI of the inflammatory response revealed marked differences in both the development and steady state responses to the intradermal injection of histamine (1-3 mumol/L) and bradykinin (1 mumol/L). The development of the flare and the weal response to both histamine and bradykinin was significantly reduced by cetirizine but not by loratadine. The histamine-induced flare area fell by 57 +/- 4% (mean +/- SEM, n = 10, P < 0.001) after cetirizine and the area of the weal fell by 73 +/- 11% (P < 0.009). Bradykinin-induced inflammatory responses were similarly reduced by cetirizine, the weal by 60 +/- 16% (P < 0.02) and the flare by 61 +/- 4% (P < 0.005). Measurement of histamine concentration in skin using microdialysis, in six subjects, confirmed that histamine levels rose in the dialysate collected from the weal to 310 +/- 16 nmol/L following injection of histamine. Histamine levels also rose following bradykinin injection in some subjects (mean 147 +/- 46 nmol/L, range 18-336). Little increase in histamine concentration was seen in the dialysate from the flare following injection of either histamine or bradykinin. The histamine concentration in dialysate from unprovoked skin was 4.19 +/- 0.75 nmol/L. These data reveal differences in the dermal responses to different mediators when assessed using scanning LDI. They confirm that histamine is released within the weal but not the flare response to the intradermal injection of both histamine and bradykinin and that its effects on the local vasculature to cause the oedematous weal and the axon reflex-mediated flare are significantly attenuated by the H1 antagonist cetirizine and to a lesser extent by the H1 antagonist loratadine.

Adult↗