Histologische und spektralphotometrische Untersuchungen zur Bestimmung der „Stärke der Metachromotropie“ mit Dichlorpseudoisocyanin

Zusammenfassung Dichlorpseudoisocyanin (DPI) wurde hinsichtlich seines metachromatischen Verhaltens in vitro spektralphotometrisch geprüft. Nach Zugabe eines der Substrate Heparin, Chondroitinsulfat oder Polyron bildet sich im Bereich von 585–600 nm eine metachromatische Absorptionsbande aus. Diese wird durch Wasserstoffionen, Neutralsalze, Alkohol sowie Farbstoffverdünnung unterdrückt. In diesbezüglichen Testreihen erweist sich der DPI-Heparin-Komplex als wesentlich resistenter als ein entsprechender DPI-Chondroitinsulfatoder DPI-Polyron-Komplex.In analog angelegten Testreihen am histologischen Schnitt konnte gezeigt werden, daß die einzelnen sauren Gewebskomponenten gegenüber DPI eine unterschiedliche Stärke der Metachromotropie haben. Als am stärksten resistent gegen Störfaktoren erweisen sich die Heparin enthaltenden Mastzellen, gefolgt von Knorpelgrundsubstanz und Drüsenschleim.Die DPI-Metachromasie eignet sich gut zur Klassifizierung saurer Gewebskomponenten aufgrund der unterschiedlichen Stärke der Metachromotropie. Ihr Vorteil gegenüber der Toluidinblau- oder Acridinorange-Metachromasie liegt vor allem darin, daß die mit Dichlorpseudoisocyanin metachromatisch gefärbten Gewebskomponenten unter Verwendung eines Linienfilters (579 nm) auch im Schwarzweiß-Bild einwandfrei dokumentiert werden können.

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Histological and spectrophotometrical investigations to determine the strength of metachromotropy by dichlorpseudoisocyanine

Summary Dichlorpseudoisocyanine (DPI) was tested in vitro spectrophotometrically in view of its metachromatic effects. After the addition of one of the substrates heparin, chondroitin sulfate or polyron a marked metachromatic maximum is noted near 585–600 nm. This metachromatic absorption band is depressed by H⁺-ions, neutral salts, alcohol and the dilution of the dye-stuff. In test series it was shown that in this respect the DPI-heparincomplex is much more resistant than the complexes with chondroitin sulfate or polyron.Histological preparations in analogical test series showed that various acid components of the tissue possess a different strength of metachromotropy against DPI. Mast cells containing heparin proved most resistant against factors irritating metachromasia; they are followed by cartilage ground substance and glandular mucins.DPI-metachromasia is a valuable test to classify different acid tissue components with regard to their strength of metachromotropy. The advantage of this method in comparison with toluidine blue or acridine orange metachromasia is, that tissue components stained metachromatically with dichlorpseudoisocyanine may be documented successfully in black and white photographs by the use of a line filter (579 nm).

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Mit Unterstützung durch die Deutsche Forschungsgemeinschaft.

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Ständige Adresse: 171 Tokyo, Toshima, Minami-Nagasaki, 4-13-35-1102/Japan.     

Special somatic spine synapses in the ciliary ganglion of the chick

Summary Somatic spine synapses modified with postsynaptic electron opaque materials were found in the axo-somatic ciliary ganglion synapse of the chick.A part of the postsynaptic cell body protrudes into the presynaptic calyciform ending as a somatic spine with about 1 in length and 0.15 in diameter, and forms the so-called synaptic complex with presynaptic process. Moreover, conspicuous electron opaque materials can be seen in the central axis of the spine, except for its end portion. Sometimes, these opaque materials are seen as arrayed dots.The morphological characteristics of the somatic spine synapses in this study are quite similar to that found in the habenula and interpeduncular nuclei of the cat (Milhaud and Pappas, 1966). the biological significance of which is obscure at present.This work was supported in part by grant from the Education Ministry of Japan.     

Joint transfer of genetic markers in Bacillus subtilis

Takahashi, I. (McMaster University, Hamilton, Ontario, Canada). Joint transfer of genetic markers in Bacillus subtilis. J. Bacteriol. 91:101-105. 1966.-To compare the processes of genetic incorporation in transduction and transformation in Bacillus subtilis, several groups of linked markers were selected and the degree of linkage was determined by the two means of genetic exchange. Bacteriophage PBS 1 was used in transduction experiments. In all cases, frequencies of joint transfer, as expressed by the cotransfer index or by percentage of joint transfer, were higher in transduction than in transformation. With a pair of closely linked markers, the frequency of joint transduction was only slightly higher than that of joint transformation. On the other hand, a considerably higher degree of linkage was obtained by transduction when loosely linked markers were examined. It appears that the size of donor chromosome transferred by transducing phage particles is much larger than that incorporated by recipient cells in transformation. It is suggested that transduction in B. subtilis may be a useful tool in extending further the linkage groups established by the transformation technique.