Contact Dermatitis In Guinea Pigs Research Articles

Oral and epicutaneous desensitization in urushiol contact dermatitis in guinea pigs sensitized by 2 methods of different sensitizing potency.

This investigation was conducted to study the relationship between the different intensities of sensitization to urushiol induced by the maximization test method (MT) or by the ear-flank method (EF) in guinea pigs, and hyposensitization induced by repeated oral and/or epicutaneous administration of the allergen, and to compare the immune tolerance achieved between these routes of dosing. During the observation period of 10 weeks, both oral and epicutaneous administration produced hyposensitization to urushiol after weak sensitization by EF; however, only combined administrations via the oral and epicutaneous routes achieved hyposensitization after potent sensitization, while inadequate tolerance was induced by oral dosing and none by epicutaneous dosing. Thus, it is indicated that difficulty in establishing immune tolerance may increase with increasing intensity of primary sensitization, and that hyposensitizing potency tends to increase in the order epicutaneous, oral and combined (e.p.+p.o.) administrations of urushiol.

Increase in epidermal ATPase-positive Langerhans cells following topical application of 70% deacetylated chitin (DAC-70) in DNCB-sensitized contact dermatitis in guinea pigs preliminary report

Chitin is a polymer of D-glucosamine, beta-poly-N-acetyl D-glucosamine. The chitin derivative, 70% deacetylated chitin (DAC-70), is immunopotentiating. The present study was conducted to determine the immunoregulatory events in skin following topical application of DAC-70 to DNCB-sensitized contact dermatitis in guinea pigs. On the 3rd day of treatment, DNCB-induced erythema was reduced in all five guinea pigs treated with 10% or 3.5% DAC-70 ointment. On the 7th day of treatment, ATPase-positive Langerhans cell (LC) density in epidermal sheets was 1021 + 131/mm2 (mean + SD) for 10% DAC-70-treated skin, and 1000 + 130/mm2 for 3.5% DAC-70-treated skin, both values exceeding 782 + 65/mm2 for normal epidermis. The value in DAC-70-treated samples was significantly greater (P < 0.01) than in normal epidermis. DAC-70 thus appears to have an immunoregulatory effect by increasing the number of epidermal LCs.

Histochemical studies on the effect of 70% deacetylated chitin (DAC-70) to DNCB-sensitized contact dermatitis in guinea pigs

Histochemical studies on the effect of 70% deacetylated chitin (DAC-70) to DNCB-sensitized contact dermatitis in guinea pigs

Microtubule disassembly induced by sensitizing halogenated nitrobenzene derivatives

The potency of certain halogenated nitrobenzene derivatives to induce allergic contact dermatitis has been demonstrated in guinea-pigs and in man. As the first step towards understanding the mechanisms of cellular injury induced by these sensitizers, we have studied by fluorescence microscopy the effects of 13 halogenated (nitro)benzene derivatives on microtubule organization in mouse 3T3 fibroblasts and human AG1522 skin fibroblasts. Untreated cells have numerous microtubules distributed in a network fashion throughout the cytoplasm and extending to the cell periphery. Exposing cells for 3 hr to micromolar doses of halogenated nitrobenzene derivatives, which induce allergic contact dermatitis in guinea-pigs and man, resulted in a dose-dependent disassembly of microtubules. In contrast, incubation with 10–70 times higher doses of seven halogenated (nitro)benzene derivatives that do not sensitize guinea-pigs or man, had no discernible effect on microtubule organization of both cell types under identical assay conditions. Thus, for the 13 halogenated (nitro)benzene derivatives tested in this study, a 100% positive correlation exists between the sensitizing capacity as determined by in vivo tests on guinea-pigs and man (Landsteiner and Jacobs, 1936) and the ability to cause microtubule disassembly in cultured cells. These results may provide the basis for developing an in vitro screening assay for identifying other potential halogenated nitrobenzene sensitizers. In addition, these studies represent a new approach to investigating the mechanisms of contact sensitivity induced by simple chemicals.

Topical cyclosporine: effects on allergic contact dermatitis in guinea pigs.

Cyclosporine (CSA) is an effective immunosuppressive agent and is used in tissue transplantation. The present investigation was undertaken to determine the effect of topical delivery of CSA on allergic contact dermatitis in guinea pigs. Topical 15% CSA in an azone (1-dodecylazacycloheptan-2-one)-containing vehicle blocked local elicitation in previously dinitrochlorobenzene (DNCB) sensitized animals that received a single topical application just prior to elicitation. Elicitation was not blocked at a distant site, indicating a local effect of topical CSA. In contrast, topical CSA when applied twice daily for a total of 5 applications during sensitization only, did not block subsequent elicitation. These experiments suggest that cyclosporine may be beneficial in the therapy of human contact dermatitis, as well as other T cell mediated dermatoses.

UVB serum factor: suppression of allergic contact dermatitis in guinea pigs.

Serum from guinea pigs exposed to a single high dose of UVB and from controls was injected into the spleen of normal animals 5 days prior to sensitization. When 1.0 ml was transferred 4.5 h after irradiation, immunosuppression was obtained. Transfer of 1.5 ml of serum 2.5 h after irradiation failed to induce immunosuppression. This experimental model in guinea pigs might be valuable in further studies investigating the effect of other modalities of ultraviolet exposure (e.g., PUVA or high-dose UVA) on the release of soluble serum factor(s) inducing immunosuppression in allergic contact dermatitis.

Induction of Contact Dermatitis in Guinea Pigs by Quaternary Ammonium Compounds: The Mechanism of Antigen Formation

Induction of Contact Dermatitis in Guinea Pigs by Quaternary Ammonium Compounds: The Mechanism of Antigen Formation

ChemInform Abstract: Allergenic α‐Methylene‐γ‐butyrolactones. Study of the Capacity of β‐Acetoxy‐ and β‐Hydroxy‐α‐methylene‐γ‐butyrolactones to Induce Allergic Contact Dermatitis in Guinea Pigs.

Abstract(±)‐Tulipalin B (V) wird auf dem im Schema angegebenen Reaktionsweg synthetisiert.

Allergenic alpha-methylene-gamma-butyrolactones. Study of the capacity of beta-acetoxy- and beta-hydroxy-alpha-methylene-gamma-butyrolactones to induce allergic contact dermatitis in guinea pigs.

(+/-)-Tulipalin B was prepared in six steps from phenyl sulfide and ethyl 2-bromopropionate. The sensitizing power in the skin of (+/-)-tulipalin A (1a) and B (1b) and of the beta-acetoxy derivatives (1c) was studied. All are able to induce allergic contact dermatitis (ACD) and give cross-reactions. gamma,gamma-Disubstituted analogues (with a -(CH2)5- chain in the gamma-position) were synthesized and used to induce ACD in guinea pigs: they all were sensitizers and cross-reacted. However no cross-reaction was demonstrated between gamma,gamma-unsubstituted and gamma,gamma-substituted compounds showing a great specificity of ACD.

Treatment of dermatitis from parthenin.

Composites and some other plants containing sesquiterpene lactones, frequently cause allergic contact dermatitis in man. No treatment is available to control this disease successfully. We have used an amino acid, cysteine, to treat allergic contact dermatitis in guinea pigs sensitized to parthenin, a major sesquiterpene lactone of an allergenic weed, Parthenium hysterophorus L. Cysteine treatment of the allergic reaction induced by parthenin resulted in (a) reduced time of recovery and (b) reduced intensity of the skin reaction.

Inhibition of delayed hypersensitivity reactions by a new agent, CIS-1-methyl-4-isohexylcyclohexane carboxylic acid (IG-10)

A newly synthesized compound, cis-1-methyl-4-isohexylcyclohexane carboxylic acid (IG-10), has been reported as an inhibitor of delayed hypersensitivity reaction. In the present paper, the mechanisms regarding the inhibitory action of IG-10 was investigated on delayed hypersensitivity reactions, p-Phenylenediamine-induced contact dermatitis in guinea pigs was significantly inhibited when the drugs was given in a dose of 100 mg/kg p.o. at various times after challenge with the antigen. IG-10 inhibited both contact dermatitis and monocytes or neutrophils infiltrations induced by picryl chloride in mice. A skin reaction, similar to that seen in the case of delayed hypersensitivity reaction, was induced by an intradermal injection of phytohemagglutinin-P (PHA-P) stimulated lumphocytes in guinea pigs. This reaction was a useful method for assessing the effect of drugs on the release of lymphokines, particularly skin reactive factor (SRF). IG-10 in a concentration of 10 −5 g/ml inhibited the release of SRF as well as the release of migration inhibitory factor (MIF) from guinea pig lymphocytes stimulated by PHA-P. The reduction of Δ 4-3-ketone of aldosterone and/or hydrocortisone by rat liver homogenates was not affected with IG-10, unlike that seen in the case of glycyrrhizin.

Kathon Biocide: Manifestation of Delayed Contact Dermatitis in Guinea Pigs Is Dependent on the Concentration for Induction and Challenge

The potential of Kathon biocide, an aqueous solution containing, as active ingredients (a.i.), a mixture of 5-chloro-2-methyl-4-isothiazolin-3-one and 2-methyl-4-isothiazolin-3-one (14.4% a.i.), to produce delayed contact dermatitis, a sensitization response, was evaluated in outbred Hartley guinea pigs by a modified Buehler's occluded epicutaneous patch technique. The relationship of the response as a function of induction/elicitation concentrations was investigated. Groups of guinea pigs received 9 induction doses of the biocide, 3 times a week, at concentrations ranging from 25-2000 ppm a.i. These guinea pigs were challenged with the biocide at concentrations ranging from 20-2000 ppm a.i., and the application sites were scored for erythema 24 and 48 h after the challenge. The incidence of delayed contact dermatitis in induced guinea pigs was dependent on both the induction and challenge concentrations. The EC50 (concentration at which delayed contact dermatitis was seen in 50% of the population) for induction at a challenge concentration of 2000 ppm a.i., a nonirritating concentration, was estimated to be 88 ppm a.i. with a slope of 3.47 probits/unit log concentration. The EC50 for elicitation at an induction concentration of 1000 ppm a.i. was estimated to be 429 ppm a.i. with a slope of 2.74 probits/unit log concentration. These data demonstrate that for Kathon biocide, there is an induction/elicitation concentration dependency for delayed contact dermatitis response, and there is a "no response concentration" zone where the biocide can be used without concern for clinically significant delayed contact dermatitis. In comparison with a previous study, these data also suggest that the number of induction doses may be an important factor in demonstrating the sensitization potential of a chemical.

Studies on the skin-sensitizing properties of the “pepeo” tree, Mauria puberula (Anacardiaceae)

The oleoresin of <i>Mauria puberula</i> (MP), a poisonous species of the Anacardiaceae that is indigenous to the Venezuelan Andes, was shown to cause both primary irritant dermatitis and allergic contact dermatitis in guinea pigs and humans. Cross-sensitization reactions were found in persons with known allergy to <i>Toxicodendron</i> spp. or <i>Lithraea caustica</i> and in guinea pigs sensitized to 3-<i>n</i>-pentadecylcatechol. These results suggest that the active principles of MP are probably chemically related to, but not identical to, those of <i>Toxicodendron</i>.

Arachidonic acid metabolism in skin: experimental contact dermatitis in guinea pigs.

The cutaneous metabolism of exogenous arachidonic acid and endoperoxide (PGH2) to prostaglandins and hydroxy-fatty acids was investigated in experimental contact dermatitis in guinea pigs and compared to normal skin, unsensitized animals treated with the allergen dinitrochlorobenzene, and Trafuril-induced irritant dermatitis. The main alterations of cutaneous arachidonate metabolism in contact dermatitis comprise: (1) an inhibition of PGD2 synthesis; (2) a switch from predominant PGD2 production to a predominance of PGE2 and (3) a marked inhibition of the lipoxygenase activity.

The sensitization potential of some perfume ingredients tested using a modified Draize procedure

A modified Draize procedure was used to test 23 natural and 46 synthetic perfume ingredients for their potential to induce allergic contact dermatitis in guinea pigs. Fifty-three ingredients did not induce sensitization. Two synthetic ingredients showed a strong sensitization potential and 14 ingredients, 7 natural and 7 synthetic, showed a weak sensitization potential. The findings indicate that there is little risk of sensitization in man to most of these perfume ingredients.

The role of langerhans cells in contact allergy. I. An ultrastructural study in actively induced contact dermatitis in guinea pigs

Abstract is not availeble.

Quantitative and qualitative dynamics of the epidermal and cellular inflammatory reaction in primary toxic and allergic dinitrochlorobenzene contact dermatitis in guinea pigs.

Histochemical and quantitative cytochemical investigations have been performed in primary toxic and allergic dinitrochlorobenzene (DNCB) contact dermatitis in the guinea pig. Before histomorphological changes become obvious, a marked decrease in the activity of enzymes of the energy producing metabolism and of hydrolytic enzymes is seen in the epidermis. These changes are best expressed in the primary toxic reaction and are interpreted as a non-specific disturbance of cellular metabolism. The changes in the corium in the primary toxic DNCB-contact dermatitis are characterized by an early reaction of local mesenchymal cells followed by the invasion of polymorphnuclear leucocytes. In the allergic delayed type reaction an early invasion and proliferation of mononuclear phagocytes and a later lymphocytic reaction is seen; the ratio of lymphocytes and mononuclear phagocytes after 24–48 h is about 1:1; mast cells show an increase in number. The significance of extracellularly located esterase-positive granules in the very close environment of macrophages in the allergic contact dermatitis is discussed. A peculiar species-dependent enzymecytochemical behaviour of blood cells in guinea pigs is described.

3H-thymidine incorporation into circulating white cells during allergic and irritant dermatitis in guinea pigs.

During allergic and irritant contact dermatitis in guinea pigs produced by application of 1-chloro-2,4-dinitrobenzene and croton oils, respectively, the white cells of the peripheral blood were counted and examined for incorporation of &lt;sup&gt;3&lt;/sup&gt;H-thymidine. White cell counts remained at relatively constant levels during the dermatitis. During allergic dermatitis, however, &lt;sup&gt;3&lt;/sup&gt;H incorporation increased two- to five-fold, whereas during irritant dermatitis no increase occurred.

Influence on the induction and elicitation of contact-dermatitis in guinea pigs.

ABSTRACTIn the present experiment the authors investigated whether the previously found influence of exteroceptive stimulation of the extremities on the elicitation of an allergic or secondary reaction of the skin in guinea‐pigs to DNCB is elaborated via the toxic or primary reaction. An influence of the stimulation on the primary reaction was found too.The experiment was conducted in two parts: 1) Two experimental groups were stimulated electrically on different schedules, continuous or repetitive. A 48 hour interval between stimulation and application of DNCB was added. The skin reactions were rated by 4 observers on a 5‐point rating scale. 2) Two experimental groups were stimulated on the same schedules as above. The corticoid levels were measured at different times after stimulation.The experiment showed that the probability of a skin reaction on the allergic (secondary) contact to a threshold dose was greater for the continuously stimulated group than for the control group.Relationships between corticoid levels and skin reactions were discussed. The hypothesis that stimulation has a direct influence on the allergic contact was supported.

Preliminary Studies on Use of Sensitized Guinea Pigs in the Evaluation of Protective Ointments

A procedure for the development of allergic contact dermatitis in guinea pigs in which six potential allergens were used and a method for testing the effectiveness of barrier ointments, creams, and aerosols in preventing contact dermatitis in sensitized guinea pigs (to oster oil) have been described.