H. Korr

Interrelationships between polyamines and nucleic acids. III. Metabolic and autoradiographic studies of putrescine in mouse brain

Abstract To corroborate further the supposed functional relation between polyamines and nucleic acids, regional differences of the metabolism of putrescine in vivo have been studied with an autoradiographic technique. The regions of maximal synthesis of spermidine and spermine from radioactive putrescine were identical to a large extent with those of maximal protein and RNA synthesis. As had been already demonstrated for radioactive amino acids and for some precursors of RNA, we also found the highest accumulations of radioacttivity from intraperitoneally injected [2,3- 3 H]-putrescine to be generally in the region rich in nerve cells. The highest proportion of radioactivity was represented by spermidine and spermine. In the case of putrescine some tracts contained even more radioactive material than the surrounding gray matter, and these tracts were not labelled after the application of radioactive amino acids. An appreciable amount of radioactive putrescine in mouse brain was observed even 28 days after the administration of the radioactive compound. This suggests the existence of a degradative pathway from spermidine and spermine to putrescine in the mammalian organism.

Cholesterinkristalle in Kryostat-Gefrierschnitten von nervösem Gewebe als Ursache von Artefakten in Autoradiogrammen

SummaryIn frozen sections of native or formaldehyde or glutaraldehyde fixed nervous tissue, layers of cholesterol crystals have been observed after storage at room temperature, most abundantly in the regions rich in white matter. The formation of the cholesterol depositions could be prevented by treatment of the sections with gaseous formaldehyde at 80° C for several hours, immediately after their removal of the cryostat. The distribution of the radioactive material in the sections was not affected by the formaldehyde treatment. Chemographic effects in the autoradiograms have not been observed. The techniques of autoradiography disturbed by the depositions of cholesterol crystals are reviewed.ZusammenfassungAuf Kryostat- Gefrierschnitten von nativem und auch von Formaldehydoder Glutaraldehyd-fixiertem nervösem Gewebe entstehen besonders über der weißen Substanz Cholesterinkristalle in oft dichten Lagen, wenn die trockenen Schnitte bei Raumtemperatur aufbewahrt werden. Ein mehrstündiges Einwirken von gasförmigem Formaldehyd bei 80° C auf die Schnitte sofort nach der Entnahme aus dem Kryostaten verhindert die Kristallbildung. Diese Behandlung der Schnitte beeinflußt die im histologischen Präparat vorhandene Isotopenverteilung nicht und führt auch nicht zu chemographischen Effekten bei autoradiographischen Untersuchungen. Es wird berichtet, bei welchen autoradiographischen Techniken Artefakte durch Cholesterinkristalle zu erwarten sind und welche Auswirkungen diese Kristalle auf die Auswertung von Autoradiogrammen haben.

Silbernetze als Objektträger in der Autoradiographie elektronenmikroskopischer Präparate

Tr i f f t e in g u t gebi indel ter , i n t ens ive r E l e k t r o n e n s t r a h l y o n e twa t 0 0 k e V auf eine Werkst f lekoberf l~che, so k a n n das Mater ia l an der Auf t ref fs te l le s chme lzen u n d v e r d a m p f e n . Diese W i r k u n g wird u . a . z u m SchweiBen u n d B o h r e n yon Metal len ausgenu t z t . Der Ma te r i a l ab t r ag be im B o h r e n k a n n (je n a c h Mater ia l e igenscha f t en u n d B e s t r a h l u n g s p a r a m e t e r ) e rup t ionsa r t i g ahl au fen [t, 2]. E in solcher Ausstol3 yon Material , der an die E r u p t i o n yon W a s s e r u n d D a m p f be im Geiser er inner t , wird n a c h [t] als W i r k u n g des S iedeverzugs gedeute t . A u c h Tafelglas k a n n m a n m i t kurzze i t igen E l e k t r o n e n i m p u l s e n bohren . Mater ia l spr i tzer in der U m g e b u n g dieser B o h r u n g e n weisen auf e inen e rup t i onsa r t i gen Auss toB der Schmelze hin. Gasb lasen b e o b a c h t e n k6nnen , die d i rekt nach einer pI6tzl ichen M a t e r i a l v e r d a m p f u n g e n t s t a n d e n sind. B e t r a c h t e t m a n m i t d e m Auf l i ch tmik roskop das Innere der be im Siedevorgang n a c h U n t e r b r e c h u n g der E lek t ronenbe s t r a h l u n g e r s t a r r t en Glasschmelze in E in fa l l s r i ch tung des E lek t ronens t r ah l s , so erh~lt m a n Bilder entspr . Fig. I. U n t e r den vie len v o m Siedevorgang s t a m m e n d e n r u n d e n Blasen s ind einige s t e rna r t i g yon e inem P u n k t au sgehende Blasen zu erkennen. Hier is t das Glas of fenbar sofor t n a c h der pl6tzl ichen V e r d a m p f u n g e r s t a r r t (i~r statu nasce~di).

Autoradiographische Untersuchungen zur Verteilung von Mescalin und dessen Einfluß auf die zentrale Erregung bei Mäusen

SummaryAfter the injection of radioactive mescaline into mice the distribution of radioactivity was studied in different organs with biochemical and autoradiographic techniques. The half-life time of mescaline in the brain of mice was found to be about 55 min. One hour after injection, the highest level of radioactivity was found in thesoma rich areas of the cortex and of the brainstem. At this time the choroid plexus contained the highest amount of radioactivity within the brain. Six hours after the mescaline injection the radioactive material was concentrated more in the hippocampus compared with other areas of grey matter, whereas the plexus was nearly free of radioactivity. Motility increased parallel with the enrichment of the radioactivity in the cornu ammonis. Within the retina the layers with myelinated fibers were more radioactive than those containing the perikarya. A marked storage of radioactive material in the perikarya of the spinal ganglia was also observed. In the bone-marrow and in other reticulo-endothelial structures a high concentration of radioactivity was also found. In the liver the radioactivity was accumulated in the bile ducts and around the central veins. These autoradiograms were similar to the pictures which are obtained from Kupffers cells by injection of Chinese ink. The adrenal medulla and the isles of Langerhans in the pancreas were also marked selectively.

Autoradiographic studies on the distribution of 3H-2,3,4-trimethoxy-?-phenylethylamine in the mouse

The regional distribution of radioactivity was studied in the brain and in other organs of the mouse by light microscopic autoradiography after injection of 3H-2,3,4-trimethoxy-Β-phenylethylamine (2,3,4-TMPEA), a nonhallucinogenic isomer of mescaline. The distribution patterns were compared with biochemical and autoradiographic results obtained after 3H-mescaline.Although 2,3,4-TMPEA is rapidly deaminated compared to mescaline its distribution pattern in the brain is similar to that of mescaline at 1 h after injection. However, contrary to mescaline the radioactive labeling becomes more and more homogenously distributed in the brain with time. The distribution patterns in kidney, pancreas, adrenal, and spinal ganglia were also different from those observed after application of 3H-mescaline.

Das postembryonale Wachstum verschiedener Hirnbereiche bei Orchesella villosa L. (Ins., Collembola)

The brain volume and the volumes of different brain structures as well as their allometric exponents were determined for 9 different instar phases. The mode of growth of Orchesella villosa was compared with that of Pterygotes. Some new facts about the biology of Orchesella derived from observations of separately kept individuals are given.

Autoradiographic studies on the distribution of 3H-mescaline in the brain of the marmoset, Callithrix jacchus

Autoradiographs of the brain of the marmoset, Callithrix jacchus, show a strong labeling of the hippocampus and the N. amygdalae 18 h after injection of 3H-mescaline. A similar characteristic autoradiographic pattern was previously found in the mouse brain, too.