Permeability In Guinea Pig Skin Research Articles

Absorption of the nerve agent VX ( O-ethyl- S-[2(di-isopropylamino)ethyl] methyl phosphonothioate) through pig, human and guinea pig skin in vitro

The physico-chemical properties of VX make the skin the most likely route of absorption into the human body. The development of effective medical countermeasures against such percutaneous threat agents relies on the use of appropriate animal models, as the inherent toxicity of nerve agents precludes the use of human volunteers. Previous studies have characterised the mechanism of nerve agent toxicity in rodent models, however, it is generally accepted that one of the most appropriate animal models for human skin absorption is the domestic pig. The purpose of the present study was to measure and compare the skin absorption kinetics of VX in vitro using pig, human and guinea pig skin to highlight any potential species differences in skin permeability. When undiluted VX was applied directly to the skin, the permeability of guinea pig skin was approximately 7-fold greater than human skin. There was no significant difference in the permeability of pig and human skin. When VX diluted with isopropyl alcohol was applied to the skin, the permeability of guinea pig skin was approximately 4-fold greater than human skin. There was no significant difference in the permeability of pig and human skin. From this data it may be inferred that dermatomed, abdominal pig skin is an appropriate model for the human skin absorption of VX.

Effect of substance P and Sar9Met(O2)11-substance P on cutaneous capillary permeability in guinea pig skin.

The purpose of this study was to assess the effect of several drugs on the increase in cutaneous capillary permeability induced by intradermal injection of substance P (SP) and Sar9Met(O2)11-SP in guinea pig skin. On the one hand, the increase in cutaneous capillary permeability was partly reduced by spantide, promethazine, atropine or SR 40037, an inhibitor of the angiotensin-converting enzyme. On the other hand, norepinephrine and B3824, a B2-antagonist of bradykinin, showed an enhancing effect. Our results suggest that the effect of SP and Sar9Met(O2)11-SP in guinea pigs is partly mediated by histamine and acetylcholine, and that there is a relationship between tachykinins and bradykinin.

Recombinant Neutral Endopeptidase Attenuates Substance P-Induced Plasma Extravasation in the Guinea Pig Skin

To determine whether exogenously administered neutral endopeptidase (NEP; enkephalinase, EC 3.4.24.11) inhibits the substance P-induced increase in vascular permeability in the skin, we examined the effects of recombinant human NEP on plasma extravasation induced by intradermal injection of substance P in guinea pig skin. Injection of substance P (2.5 X 10(-8) M) induced significant plasma extravasation in the skin (53 +/- 4 mm2 of Evans blue extravasation; mean +/- 1 SEM). In vitro incubation of substance P with recombinant human NEP prior to injection prevented the substance P-induced plasma extravasation in the skin in a dose-dependent fashion. Intradermal preinjection of recombinant human NEP partially inhibited plasma extravasation induced by subsequent injection of substance P (52 +/- 9% of the control without NEP). The H1 and H2 histamine antagonists pyrilamine and cimetidine, and a muscarinic antagonist, atropine, had no effects on substance P-induced responses. Two products of substance P degradation by NEP containing the carboxy-terminal portion, substance P7-11 and substance P8-11, were also without effect. These findings suggest that recombinant human NEP can attenuate substance P-induced increases in vascular permeability in guinea pig skin and, therefore, may be useful in treating dermatologic disorders in which abnormal responses to substance P or other neuropeptides cleaved by NEP may occur.

Factor C3f is a spasmogenic fragment released from C3b by factors I and H: The heptadeca-peptide C3f was synthesized and characterized

C3f, a heptadeca-peptide having the amino acid sequence of NH 2-Ser-Ser-Lys-Ile-Thr-His-Arg-Ile-His-Trp-Glu-Ser-Ala-Ser-Leu-Leu-Arg-COOH, is liberated during the catabolic degradation of C3b in serum. The amino acid sequence of C3f is known both from the cDNA-derived structure of C3 and from protein analysis after isolation of the natural factor. C3f was synthesized by solid phase peptide synthesis. Both natural and synthetic C3f had identical retention times by RP-18 high performance liquid chromatography (HPLC) analysis and the respective amino acid compositions agreed with the expected theoretical values. C3f, but not des-Arg-C3f, was weakly spasmogenic inducing contraction of guinea pig ileum at a level of 5–10 × 10 −6 M. Since C3f and C3a were cross-tachyphylactic, it was concluded that these two spasmogens compete for the same receptors. Both C3f and des-Arg-C3f at concns of 1–4 × 10 −4 M enhanced vascular permeability in guinea pig skin. These observations further suggest that C3f functionally resembles C3a anaphylatoxin. Formation of C3f in human serum following CVF activation of C3 could be demonstrated by radioimmunoassay (RIA). Digestion of C3f with purified human serum carboxypeptidase N produced C3f-desArg. These observations suggest that when serum complement protein C3 undergoes conversion to C3b, further degradation by Factors H and I readily generates C3f. C3f is a weak spasmogen that functions like C3a anaphylatoxin and C3f-desArg is a major metabolite in serum.

Activation of Hageman Factor and Prekallikrein and Generation of Kinin by Various Microbial Proteinases

Activation of the Hageman factor-kallikrein-kinin system by serratial 56-kDa proteinase was previously demonstrated (Matsumoto, K., Yamamoto, T., Kamata, T., and Maeda, H. (1984) J. Biochem. (Tokyo) 96, 739-749; Kamata, R., Yamamoto, T., Matsumoto, K., and Maeda, H. (1985) Infect. Immun. 48, 747-753). To investigate whether the activation of the system is specific for 56-kDa proteinase or is found similarly with other microbial proteinases, 11 proteinases of microbial origins were studied; the 56-kDa proteinase was the control. For in vitro studies, activation of guinea pig Hageman factor and prekallikrein was examined in purified systems as well as in plasma as a zymogen source. Specific antibodies and inhibitors confirmed the activation steps of the cascade. In the in vivo study the enhancement of vascular permeability in guinea pig skin and its sensitivity to inhibitors of activated Hageman factor, plasma kallikrein, or a kininase were examined. The results from the in vivo experiments were consistent with those in vitro. Taking all the data together, we classified the 11 microbial proteinases into three groups as follows: 1) Serratia marcescens 56-, 60-, and 73-kDa proteinases, Pseudomonas aeruginosa alkaline proteinase and elastase, and Aspergillus melleus proteinase (this group activated Hageman factor but not prekallikrein); 2) Vibrio vulnificus proteinase, subtilisin from Bacillus subtilis, and thermolysin from Bacillus stearothermophilus (this group activated both Hageman factor and prekallikrein); 3) Streptomyces caespitosus proteinase and V8 proteinase from Staphylococcus aureus (this group activated neither Hageman factor nor prekallikrein, but generated kinin from high molecular weight kininogen directly).

Tachykinin receptor subtype that mediates the increase in vascular permeability in guinea pig skin

To determine the tachykinin receptor subtype that mediates the increase in vascular permeability, we examined the rank order of potency of tachykinins for inducing plasma extravasation in guinea pig skin and the specificity of tachykinin-induced tachyphylaxis of the responses. Plasma extravasation of the skin induced by tachykinins was NK-1 (SP-P)-type response from the rank order of potency of mammalian and nonmammalian tachykinins. Tachyphylaxis of the vascular response was induced by intradermal preinjection of mammalian tachykinins and was tachykinin-specific. In substance P (SP) tachyphylaxis (where SP was preinjected), the response to SP, not to neurokinin A (NKA) or neurokinin B (NKB), was decreased. In NKA tachyphylaxis and NKB tachyphylaxis, the responce to NKA, not to SP or NKB, and the response to NKB, not to SP or NKA, were decreased, respectively. Thus, we conclude that the apparent NK-1-type response is mediated through three mammalian tachykinin receptors, NK-1, NK-2, and NK-3, which are specifically stimulated by their preferred agonist, SP, NKA, and NKB, respectively.

Neutral Endopeptidase Modulates Tachykinin-Induced Increase in Vascular Permeability in Guinea Pig Skin

To determine the regulatory role of neutral endopeptidase (NEP) in the tachykinin-induced increase in vascular permeability, we examined the effects of NEP inhibitors and of other protease inhibitors on plasma extravasation induced by intradermal injection of substance P, neurokinin A, and neurokinin B in guinea pig skin. The three tachykinins induced plasma extravasation in concentration-dependent fashions. A significant NEP activity was found to be present in the guinea pig skin. The tachykinin-induced responses were increased by the NEP inhibitors phosphoramidon and thiorphan. However, other protease inhibitors, including a kininase II inhibitor, did not affect the response. We conclude that NEP modulates the tachykinin-induced increase in vascular permeability in the skin.

Angioedema induced by a peptide derived from complement component C2.

Synthetic peptides that correspond to the COOH-terminal portion of C2b enhance vascular permeability in human and guinea pig skin. In human studies, 1 nmol of the most active peptide of 25-amino acid residues produced substantial local edema. A pentapeptide and a heptapeptide corresponding to the COOH-terminal sequence of C2b each induced contraction of estrous rat uterus in the micromole range; a peptide of 25 amino acids from this region induced a like contraction of rat uterus at a concentration 20-fold lower than the smaller peptides. The vascular permeability of guinea pig skin was enhanced by doses of these synthetic peptides in a similar fashion as that observed for the concentration of rat uterus. The induction of localized edema by intradermal injection in both the guinea pig and the human proceeds in the presence of antihistaminic drugs, suggesting that there is a histamine-independent component to the observed increase in vascular permeability. Cleavage of C2 with the enzymic subcomponent of C1, C1s, yields only C2a and C2b, and no small peptides, whereas cleavage of C2 with C1s and plasmin yields a set of small peptides. These plasmin-cleaved peptides are derived from the COOH terminus of C2b, and they induce the contraction of estrous rat uterus.

Staphylococcus aureus delta toxin as an enterotoxin.

The classical enterotoxins are known primarily for their ability to cause emesis and diarrhoea in cases of staphylococcal food poisoning but they also exhibit other biological activities. The seven antigenic types of toxin have molecular weights in the range 25 000-35 000. All types induce emesis in man and monkey and are of comparable potency. The enterotoxins seem to induce emesis by stimulating neural receptors in the intestine rather than acting on the medulla directly. The mechanism whereby diarrhoea is produced is unclear. Another product of Staphylococcus aureus which meets the more recent definition of an enterotoxin is the delta toxin. This toxin is an amphipathic peptide having an Mr of 2977 and possessing the ability to interact with a variety of hydrophobic substances. It is cytotoxic, can increase vascular permeability in guinea-pig skin, and can increase cellular cyclic AMP levels in guinea-pig ileum. In the ileum delta toxin also inhibits water absorption, apparently by increasing the bidirectional movement of Na+ and Cl- across the mucosa. This response does not appear to be mediated by cyclic AMP since the changes in ion fluxes precede the increases in cellular cyclic AMP levels. In high doses delta toxin also elicits a positive response in the neonatal mouse after intragastric inoculation.

Identification of classical anaphylatoxin as the des-Arg form of the C5a molecule: evidence of a modulator role for the oligosaccharide unit in human des-Arg74-C5a.

A functionally active and potentially lethal fragment of the fifth component of complement (C5) is generated during complement activation in serum from animals of various species. This factor, termed the "classical" anaphylatoxin, was isolated from porcine serum and was identified chemically as the des-Arg derivative of the well-characterized C5a molecule. Unlike the C3a and C4a anaphylatoxins, porcine C5a does not require the COOH-terminal arginyl residue for spasmogenic activity. Further degradation of porcine des-Arg(74)-C5a by carboxypeptidase Y removed glycine-73 and leucine-72 and decreased the intrinsic spasmogenic activity by >90%. Hence, we conclude that, although the arginyl residue is not essential, the COOH-terminal sequence Leu-Gly-Arg contributes structural information that accounts for >90% of C5a activity. Human des-Arg(74)-C5a, like its porcine counterpart, has instrinsic anaphylatoxin activity; however, higher concentrations were needed to contract the guinea pig ileal tissue (i.e., 1 muM for human des-Arg(74)-C5a versus 1 nM for porcine des-Arg(74)-C5a). Furthermore, the des-Arg form of human C5a was only 0.1% as active as porcine des-Arg(74)-C5a for enhancing vascular permeability in guinea pig skin. In addition to these biological differences, numerous chemical differences exist between the human and porcine des-Arg(74)-C5a molecules, the most prominent feature being an oligosaccharide entity associated uniquely with the human C5a. When the oligosaccharide unit of human des-Arg(74)-C5a was removed by glycosidases, leaving a single glucosamine residue attached to the side chain of asparagine-64, activity was enhanced. The human des-Arg(74)-C5a molecule devoid of the complex oligosaccharide unit exhibited 10-fold stronger spasmogenic activity and 20- to 50-fold greater permeability-enhancing activity than did human des-Arg(74)-C5a containing the oligosaccharide. Consequently, the oligosaccharide associated with human C5a modulates or suppresses potentially harmful activities of this anaphylatoxin. The relatively high levels of spasmogenic activity associated with porcine des-Arg(74)-C5a indicate that this factor is poorly controlled by endogenous serum carboxypeptidase, whereas human C5a is virtually inactivated by the enzyme. Hence, the influence of this oligosaccharide in suppressing human des-Arg(74)-C5a activity is of major physiologic importance in protecting man from potentially toxic effects of this complement factor.

Biological effects of the human complement fragments C5a and C5ades Arg on neutrophil function

The biological activity of human C5a was compared to its anaphylatoxin inactive form, C5ades Arg, using highly purified components. C5a was isolated from yeast-activated human serum and was converted to C5ades Arg by treatment with porcine carboxypeptidase B immobilized on Sepharose 6B. Both purified C5 fragments were homogeneous by polyacrylamide gel electrophoresis of radiolabeled peptides and by immunologic techniques. C5a caused increased vascular permeability in guinea pig skin with as little as 2 ng of injected material, whereas no detectable effect was seen with as much as 5000 ng of C5ades Arg. Both C5a and C5ades Arg stimulated cytochalasin B-treated human neutrophils to release the granule constituents myeloperoxidase, lysozyme, and β-glucuronidase, but not the cytoplasmic enzyme lactic dehydrogenase. However, 85- to 175-fold more C5ades Arg was required to give the same amount of release. A similar dichotomy of biologic effectiveness was seen for generation of the oxygen metabolite, superoxide anion, O2−, with or without cytochalasin B pretreatment of the cells. In contradistinction to earlier reports, C5ades Arg was chemotactic for human neutrophils in the absence of added serum between 100 to 10, 000 ng/ml, whereas C5a was active from 3 to 500 ng/ml. A 24-fold lower concentration of C5a was required to obtain a peak chemotactic response as measured by a leading front technique (5 ng/ml) as compared to a two-filter assay (120 ng/ml). In the absence of a gradient of the peptides, C5a and C5ades Arg induced enhanced random migration, i.e., exhibited chemokinetic activity. Both C5a and C5ades Arg desensitized neutrophils to further stimulation by C5a, as measured by granule secretion and chemotaxis. However, 25-to 50-fold more C5ades Arg than C5a was required for desensitization. The ability of C5ades Arg to cross-desensitize neutrophils suggests that C5ades Arg binds to the same neutrophil receptor as C5a but at a lower binding affinity. The studies reported here show that C5ades Arg is capable of interacting with neutrophils in a manner similar to that of C5a and that the difference between the two polypeptides is quantitative, not qualitative. Thus, the biologic activity of C5ades Arg and the presence of the serum carboxypeptidase B, which converts C5a to C5ades Arg, as well as the recently described helper factor for enhanced C5ades Arg chemotaxis combine to suggest that C5ades Arg may be an important phlogistic mediator in vivo.

Anti-inflammatory drug actions on allergic responses in guinea-pig skin.

Five non-steroidal anti-inflammatory drugs (indomethacin, naproxen, meclofenamic acid, feprazone and phenylbutazone: NSAIDs) and three glucocorticosteroids (dexamethasone, hydrocortisone and prednisolone) have been tested as local inhibitors of increased vascular permeability in guinea-pig skin. Lesions were induced by histamine or by antigen to evoke type I (passive cutaneous anaphylaxis), type III (reverse passive Arthus) and type IV (delayed hypersensitivity) allergic reactions. NSAIDs and glucocorticosteroids caused either weak, inconsistent inhibition or slight, high-dose inhibition of the response to histamine. None of the drugs tested showed significant inhibition of the type IV response. The NSAIDs caused dose-related inhibition of both type I and type III responses whereas glucocorticosteroids were ineffective. Maximum inhibition with the NSAIDs was never greater than 50--60% Feprazone, meclofenamic acid and indomethacin were the most potent inhibitors of histamine, PCA and Arthus responses respectively. The possible significance of the effects of these anti-inflammatory agents on vascular permeability is discussed.

有毒鱗翅類毒針毛に関する研究 : 第 3 報アオイラガ毒棘・毒針毛の形態と毒素, とくに発痛物質について

Scanning electron microscopy revealed that the spines of the slug moth caterpillar, Parasa consocia had no opening at the pointed ends, differing from the results reported by many investigators based on light microscopic observations. Fine structure of the spicules and their sockets on the 8th and 9th dorsal segments of the last instar larva was also described. PBS extracts from the spines and spicules were fractionated by a single hollow fiber concentrator (SHFC). The inner fluid in SHFC, containing substances with molecular weights higher than 15,000 (HM) was further fractionated through a Sephadex G-100 column, while the outer fluid containing lower molecular substances (LM) was fractionated through a Sephadex G-50 column. 1. Injection of crude venom from the spines and spicules into the tail vein of mice made them squeak and bite at the injected area due probably to local pains, followed by crouching posture and shiver for a few hours. Paralysis was observed at their hind legs when injected with the venom subcutaneously. 2. Thin-layer chromatography revealed the presence of histamine in both the venoms from the spines and spicules. 3. HMs and LMs separated from the crude venoms of the spines and spicules exhibited positive skin reactions in man by scratch method : Erythema and edema or wheal were the common symptoms produced by all of these fractions tested. Severe recurrent pains were produced by the HMs a few minutes after application. The pains were relieved within several hours, but contact stimuli to the applied area of the skin produced the recurrent pains for a few days. Though the LM from the spine venom also showed pain-producing activity, it differed from the HMs in its rapid action and shorter duration. 4. Each of the HMs from the spine and spicule venoms was separated into 3 fractions (HM-I-III), by column chromatography : HM-Is had a wheal producing activity in the skin test. HM-IIs had activities to produce severe pain and to contract smooth muscle of the isolated guinea pig ileum. The contraction induced by the two HM-IIs differed from that by histamine in that the former took longer time before the onset and showed longer duration of the contraction after several washes with Tyrode's solution; it also differed from the contraction caused by bradykinin in that the former showed tachyphylaxis. Moreover, self-movement of the ileum was increased during or after the contraction and it continued till the intra-ileac contents were thoroughly ejected. Contraction activity of the spine HM-II might be due to two substances, HM-IIa and HM-IIb. Stimulating effect of the spine HM-II on the polymodal receptor of dog testis was kept longer than that of bradykinin. Vascular permeability in guinea pig skin was also increased by the spine HM-I-III. 5. The LM from the spines was found to contain two active substances; one was histamine and the other was protein or polypeptide (LM-I) with a molecular weight of several thousands. LM-I possessed activities such as pain-producing, ileum-contracting without tachyphylaxis, and vascular permeability-increasing. From these results, it was suggested that LM-I might be a kinin-like substance.

Characterization of a leukotactic factor derived from psoriatic scale.

A study was made on the in vitro characteristics and in vivo biological activities of a leukotactic factor derived from psoriatic scale (PLF). Sephadex G-75 chromatography showed that PLF eluted in the region of the 12,500 dalton protein marker. It resisted heating, lyophilization, acidity (pH 3) and alkalinity (pH 11), but was destroyed by trypsin digestion. The substance attracted polymorphonuclear leukocytes (PMNs) in vitro; this ability was inhibited by antiserum to C3a and was partially reduced by antiserum to C5. Although PLF showed strong chemotactic activity for PMNs, its activity for mononuclear cells was only mild. Intradermal injection of PLF into man or guinea-pig produced an erythematous response with dense tissue neutrophilia, the time course of which was similar to that of the Arthus response. PLF also provoked increased vascular permeability in guinea-pig skin. Moreover, repeated intradermal injection of PLF to the same site in guinea-pigs led to moderate acanthosis of the overlying epidermis. These observations strongly suggest that transepidermal migration of leukocytes in psoriatic lesions is provoked by PLF, whose activity appears to reflect that of complement cleavage products, particularly C3a, presumably produced by complement activation in the subcorneal region of the epidermis. Furthermore, it is postulated that PLF may be a factor which plays a crucial role in the production of typical psoriasiform tissue changes.

Vascular permeability increase by α-toxin (phospholipase C) of Clostridium perfringens

T. Sugahara, T. Takahashi, S. Yamaya and A. Ohsaka. Vascular permeability increase by α-toxin (phospholipase C) of Clostridium perfringens. Toxicon 15, 81–87, 1977.—Highly purified α-toxin increased the vascular permeability in guinea-pig skin. This vascular permeability-increasing activity reached a minimum value at around 70°C but heating at higher temperatures inactivated it to a lesser extent. The same anomaly in heat inactivation was observed with the phospholipase C activity possessed by the toxin. By subjecting the purified toxin to isoelectric focusing, four molecular forms were isolated, all of which were associated with both vascular permeability-increasing and enzymatic activities. These results clearly demonstrated the identity of the factor responsible for the vascular permeability-increasing activity with α-toxin.

Increased cyclic adenosine 3',5'-monophosphate content in guinea pig ileum after exposure to Staphylococcus aureus delta-toxin

To compare Staphylococcus aureus delta-toxin with cholera toxin, which is known to increase cellular cyclic adenosine 3',5'-monophosphate (cAMP), studies were undertaken to determine the effect of delta-toxin on the cAMP content of guinea pig ileum maintained in vitro. Concentrations of delta-toxin as low as 0.40 mug/ml increased cAMP levels in guinea pig ileum after 2 h of incubation. Histological damage was seen in ileum exposed for 2 h to delta-toxin concentrations of 100 mug/ml. As little as 3 mug of delta-toxin increased vascular permeability in guinea pig skin. Permeability changes became evident within 5 min and were maximal within 6 h, whereas those produced by cholera toxin required 24 h to become maximal. Benadryl did not interfere with the ability of these toxins to alter vascular permeability. Purified egg lecithin reduced the effectiveness of delta-toxin in the skin but did not inhibit cholera toxin. Delta-toxin in concentrations as low as 0.1 mug/ml caused dislodgement of HeLa cells in tissue cultures. Therefore, delta-toxin appears unique in being the only bacterial toxin, currently known to alter water absorption in the ileum, that is capable of both increasing cAMP levels and being cytotoxic. These findings suggest a possible role for delta-toxin in the pathogenesis of staphylococcal enteritis.

Skin reactions induced by sera of patients with monoclonal IgG gammapathy.

Sera of some patients with monoclonal IgG gammapathy have been shown to contain a factor producing long-lasting vascular permeability in guinea pig skin. Skin reactions became positive 2 h after the intradermal injections of the sera and persisted for at least 8 h. Such activity could not be demonstrated in the sera of patients with macroglobulinemia, monoclonal IgA gammapathy, or light chain disease. This activity was associated with IgG but not IgM or IgA fractions of the patient’s serum. The activity was abolished by heating the serum at 63°C for 30 min or by treatment of the serum with ME and MIA. The activity, however, was not influenced by treatments with antihistaminics, trypsin inhibitor, or di-isopropyl-fluorophosphate.

Further characterization of a factor from endotoxin-treated serum which releases histamine and heparin from mast cells.

Upon incubation of hamster serum with bacterial endotoxin, a factor is produced which releases histamine and heparin from hamster mast cells and increases capillary permeability in guinea pig skin. The major histamine-releasing activity derived from hamster serum was characterized by gel filtration, found to have a molecular weight of approximately 60,000, and shown by electrophoresis to migrate with alpha-2- or beta-1-globulins. The ability to increase vascular permeability was not reversed by antihistamine. On the basis of these properties, the histamine-liberating factor generated by endotoxin in hamster serum differed significantly from known anaphylatoxins.

Schistosoma mansoni: Generation of anaphylatoxin by cercarial extracts

Extracts from Schistosoma mansoni cercariae generate in plasma or serum an activity which contracts the isolated guinea pig ileum. This contraction is inhibited by mepiramine (an anti-histaminic drug). The activity formed by cercarial extracts produces cross-desensitization with the classical anaphylatoxin generated by agar, and induces mast cell degranulation in guinea pig mesentery as well as enhancement of vascular permeability in guinea pig skin. The generation of this anaphylatoxin was blocked by the previous heating of the serum at 56 °C for 30 minutes and by the presence in mixture of 1 × 10 −2 M Na 33HEDTA. The possible role of this pharmacological active material in the process of skin penetration by cercariae is discussed.

Studies on human IgD—II: The lack of skin sensitizing and complement fixing activities of immunoglobulin D

Immunoglobulin D preparations isolated from three different myeloma sera failed to elicit reversed passive cutaneous anaphylaxis reactions in guinea pigs. Although the proteins aggregated readily with bisdiazotized benzidine, the aggregates did not fix complement and caused no increase in the vascular permeability of guinea pig skin. Under identical conditions human IgG preparations gave positive reactions in all tests. It is concluded that immunoglobulin D, both in its native and aggregated forms, lacks the structural features necessaru for skin binding and complement fixation.