tleft 8. ]25, 2, I938 j industrie gefunden hat 1, bildet Vitamin D 3 mit dem entsprechenden Bestrahlungsprodukt aus Iso-7-dehydro-cholesterin eine eharakteristisehe Additionsverbindung yore Schmp. 124% Eine Additionsverbinduug mit demselben Sehmelzpunkt, die mit der Additionsverbindung yon Vitamin D 3 keine Schmelzpunktsdepression gibt, erhietten wir aueh arts dem kristallisierten Thunf.schvitamin. Vitamin D~ bitdet dagegen keine analoge Additionsverbindung 2.Im Rattensehntzversueh zeigt das kristallisierte D-Vitamin der Thunfisehleber eine Wirksamkeit, die mit der des Vitamins D 2 iibereinstimmt (4oooo Intern. Einh./mg).Vor kurzem beriehteten ZUCXSR und Mitarbeiter a tiber die Gewinnung eines kristallisierten Vitamin D.dinitrobenzoates aus Thunfischleber61 und eincs Vitamin D-allophanates aus Dorsehlebertran. Die niehtkristallisierten Verseifungsprodukte dieser Ester zeigten eine molekulare Extinktion yon 1 , 3 8 --i , 4 o × i o 4~. Die gleiehe Extinktion wurde ftir das Allophanat gefunden. Aus dieser Ubereinstimmung ziehen die amerikanisehen Forseher den SehluB, dab die im Vergleieh zum Vitamin D= geringere Extinktion der rohen Verseifungsprodukte nieht, wie wit angenommen haben, durch Zersetzung w~ihrend der Verseifung hervorgerufen wird. Die Messungen m i t dem kristallisierten D-Vitamin aus ThunfischS1 zeigen aber, dab unsere Vermutting riehtig war. Die Iolgextde Tabelle gibt die mol. Extinktionen der verschiedenen D-Vitamine an (L6snngsmittel Hexan bzw. Ather). K u r z e O r i g i n a l m i t t e i l u ngen. 123
In order to study the specificity of H‐linked Ir gene control in more detail the polypeptide poly(LTyr, LGlu>poly(DLAla)–poly(LLys) ((T, G)‐A‐L) was modified by replacing the (T, G) copolymers by various defined tyrosine‐containing oligopeptides. It was found that the antibody response to all of the analogs of (T, G)‐A–L tested was influenced to some extent by H‐2‐linked Ir gene(s), the response pattern being concordant with that of (T, G)‐A–L. Some of the antigens carrying structurally and serologically distinct oligopeptides were as efficient with respect to high/low responder discrimination as (T, G)‐A–L, others including the core polypeptide A‐L itself were weakly immunogenic and gave only a small high/low responder split. Certain experimental data indicate that in addition to the tyrosine peptides the poly‐DL‐alanine side chains may play an important role for the recognition of these polypeptides. The possibility that the common response pattern could be due to an Ir gene specific mainly for the DL‐alanine peptides is discussed. Specificity of genetic control would then be relatively independent of the serological specificity of the tyrosine peptides. On the other hand, recognition of the analogs and of (T, G)‐A–L could be controlled by separate but closely linked Ir genes specific for each of the terminal peptide determinants which probably include the adjacent alanine residues. Genetic factors outside the H‐2 complex have in addition to the H‐linked Ir genes been found to exert a strong influence on the antibody response to some of the analogs of (T, G)‐A–L.
The present study has established, that cows suitably immunized with either DNP-edestin (DNP-Ed), di-DNP-gramicidin-J [(DNP)2-Gram], respectively, or p-azobenzenearsonate-Ed (ABA-Ed) synthesized and secreted reaginic antibodies (IgE) into colostrum. Whereas ABA-Ed failed to elicit more than a low response, there was however a persistent and increased antibody synthesis between 10 and 56 days after priming with DNP-Ed. Bivalent and multivalent DNP haptens differing in molecular size, degree of substitution, and rigidity were compared for their effectiveness in eliciting Prausnitz-Küstner (P-K) reactions in either newborn colostrum-deprived calves or in those 4 wk of age. The sensitization with reaginic anti-DNP antibody has been accomplished either by feeding colostrum of the immunized dam or by intradermal injection of reaginic serum or colostral whey. It could be demonstrated that equimolar doses of the bivalent α,N-(ϵ,N-DNP-aminocaproyl-)-ϵ,N-DNP-L-lysine and the multivalent dinitrophenylated bovine serum albumin were equally effective in eliciting reactions in skin sites provided that a high affinity antibody was used for sensitization. By contrast, the comparatively rigid, bivalent hapten, (DNP)2-Gram consistently failed to induce comparable reactions. Furthermore, it was clearly shown that optimal distances of determinant groups on the haptenic molecule are a prerequisite for positive P-K reactions, since α,ϵ,N-bis-DNP-lysine failed to induce comparable reactions. Concurrent sensitization of skin sites with reaginic anti-DNP and anti-ABA antibodies provides the final proof that cross-linking of two adjacent reaginic molecules on the mast cell surface by a bivalent hapten is required for effective elicitation of immediate-type reactions. This has been accomplished by utilizing the bivalent ϵ,N-DNP-α,N-[(4-hydroxy-3-azobenzenearsonic acid)-phenacetyl]-L-lysine (DNP-ABA) carrying noncross-reactive haptenic groups, which was consistently effective in eliciting P-K reactions in doubly but never in singly sensitized skin sites. It is apparent from the results that equimolar doses of monovalent haptens could completely inhibit the response to DNP-ABA. The present studies finally establish that mast cells of newborn colostrum-deprived calves lack IgE molecules on their surface. Thus, mast cells of newborn calves may be unique, to investigate the molecular mechanisms involved in immediate-type reactions more precisely.
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