Morphometrisch-ultrastrukturelle Untersuchungen am Nucleus supraopticus der Ratte nach Dehydratation

Zusammenfassung Der Nucleus supraopticus der Ratte, die einer Dehydratation ausgesetzt war, wurde ultrastrukturell-morphometrisch analysiert. Dabei zeigte sich, daß die relativen Volumenanteile der einzelnen Zellkompartimente während der fünftägigen Durstperiode eine auffallende Konstanz aufweisen. Hingegen läßt sich eine absolute Zunahme der Einzelzellvolumina und somit auch der an der Synthese und Sekretion der Neurohormone beteiligten Zellkompartimente feststellen. Die vorliegenden Befunde sprechen für einen beschleunigten Abtransport des neurosekretorischen Materials bei gesteigerter Synthese. Auf eine optimale Standardisierung der Perfusionsmethode bei Untersuchungen am neurosekretorischen Zwischenhirnsystem wird hingewiesen.

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Morphometric-ultrastructural investigations on the supraoptic nucleus of dehydrated rats

Summary The supraoptic nucleus of the dehydrated rat has been analysed by electron microscopy and morphometry. With that it appears, that the relative volumes of the different cell compartments are striking constant. Otherwise one can see an absolute increase of the cell volume together with the cell compartments which take part at the synthesis and secretion of the neurohormones. These results are expression of an accelerated move of the neurosecretory material during increased synthesis. The importance of an optimal standardization of the perfusion-method in investigations of the neurosecretory system is demonstrated.

Wesentliche Teile der vorliegenden Arbeit werden von H. F. Reinhardt der Medizinischen Fakultät der Universität Basel als Dissertation vorgelegt.     

Histochemical studies on the lipids in the epithelium of the fetal colon

Summary Large intestines from 30 fetuses with crown-rump lengths ranging from 26 to 180 mm have been studied histochemically as to their epithelial content of lipids. These lipids have been localized intracellularly and basally in the cells, and comparative studies of the colon and the small intestine have demonstrated that there are considerable amounts of lipids in the colon as compared with the small intestine.It is concluded that the main part of the lipids consist of saturated and unsaturated constituents.The possible explanations of the lipids as absorbed material, biological active material synthetized de novo or as material involved in the metabolism of fetal surface cells are discussed.This work was supported by a grant from the Aid of the Crippled Children, New York.     

Histochemische Untersuchungen über den Involutionsmechanismus der Milchdrüse

Zusammenfassung Es wurden mit histochemischen Methoden Milchdrüsen von Meerschweinchen in physiologischer und durch Kastration während der Laktationsperiode hervorgerufener Involution untersucht. Nachgewiesen wurden alkalische und saure Phosphatase (APh und SPh), unspezifische Esterase, Sukzinodehydrase, SH-Gruppen, Nukleinsäuren und Lipide. — Die Aktivität der SPh nimmt während der Involution zu. Die Bedeutung dieses Enzyms für den Rückbildungsprozeß des Drüsengewebes wird diskutiert. — Das Vorkommen der APh-Aktivität in Drüsenendstücken im Involutionsstadium kann auf die Beteiligung dieses Enzyms an der Rückresorption der mit der Milch ausgeschiedenen Substanzen hinweisen. — Zwischen der Aktivität der unspezifischen Esterase und dem Gehalt sowie der Lokalisation von Lipiden besteht eine Abhängigkeit. — Es konnten keine Unterschiede in der Sukzinodehydraseaktivität und dem DNS-Gehalt aufgezeigt werden. — Die Verminderung von SH-Gruppen und RNS hängt mit dem Aufhören der Sekretionsproduktion durch die Zellen der Drüsenendstücke der Milchdrüsen zusammen.

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Histochemical studies on the involution mechanism of the mammary gland

Summary Histochemical methods were used to study mammary glands of guinea pigs in the course of physiologic involution and that induced by castration during lactation. Alkaline and acid phosphatases, unspecific esterase, succinic dehydrogenase, SH groups, nucleic acids and lipids were determined. Acid phosphatase activity was found to be increased in mammary glands, subject to involution. The participation of the enzyme in the involutionary process of the gland tissue is discussed. The distribution of alkaline phosphatase in the secretory sections of the gland during involution would suggest the participation of the enzyme in the reabsorption of the substance secreted with milk. A correlation existing between the activity of unspecific esterase, the level and distribution of lipids in the mammary gland could be established. No differences were detected in the activity of succinic dehydrogenase and DNA level. A decrease in SH groups and RNA content is related to cessation of milk secretion.

     

Auerbach's plexus of mammals and man: Electron microscopic identification of three different types of neuronal processes in myenteric ganglia of the large intestine from rhesus monkeys,guinea-pigs and man

Summary Ganglia from Auerbach's plexus of the large intestine (caecum, appendix vermiformis, colon transversum and rectum) in man, rhesus monkey and guinea-pig are composed of nerve cells and their processes, typical Schwann cells and a vast neuropil. The neuropil consists of dendrites and axons of intrinsic nerve cell perikarya and axons of extrinsic neurons. Axonal profiles in large nerve fibre bundles are of uniform size and appearance, embedded in infoldings of Schwann cell cytoplasm and contain occasional large granular vesicles, mitochondria and neurotubules. Preterminal axons widen into vesicle filled varicosities, some of which establish synaptic contact with intrinsic nerve cell bodies.At least three different types of neuronal processes can be distinguished in the myenteric neuropil according to the size, appearance and commutual proportion of vesicles present in axonal varicosities, and their ability to accumulate exogenous 5- and 6-hydroxydopamine and 5-hydroxydopa: 1. Axonal enlargements containing a major population of small electron lucent synaptic vesicles (350–600 Å in diameter) together with a small number of membrane-bound, opaque granules (800–1,100 Å). These profiles have been identified as cholinergic axons. The boutons establish synaptic contacts with dendritic processes of intrinsic nerve cell bodies; membrane specializations are found at the preand postsynaptic sites. 2. Axonal beads of sometimes very large diameter, containing an approximately equal amount of large granular vesicles (850–1,600 Å) and small, electron lucent or faintly opaque vesicles (400–600 Å). The granular core of the large vesicles is of medium electron density and may either fill the entire vesicle or is separated from the limiting membrane by a more or less clear interspace. The fibres probably belong to intrinsic neurons, and because of the similarity of the large, membrane-bound vesicles with neurosecretory elementary granules, they have been designated p-type fibres (polypeptide fibres). The granular core of the vesicles in these fibres becomes more electron dense after treatment with 5-OH-dopa. The accumulation of an amine precursor analogue in combination with a possible storage of a polypeptide substance (or an ATP-like substance) resembles the situation in several diffusely distributed endocrine cell systems. 3. Varicosities of axons equipped with small (400–600 Å) empty or sometimes granular vesicles, medium sized (500–900 Å) vesicles with highly electron dense cores and occasional large (900–1,300 Å) granular vesicles. Pretreatment with 5-OH-dopamine increases the electron density in almost all medium-sized granular vesicles and some of the large granular vesicles; an osmiophilic core develops in some small vesicles. 6-hydroxydopamine results in degenerative changes in the varicosities of this type of neurons. Concomitantly, both catecholamine analogues markedly reduce neuronal noradrenaline in the large intestine, as demonstrated by fluorescence histochemistry and in fluorimetric determinations. The ultrastructural features of these varicosities and their reaction to 5- and 6-OH-dopamine indicate that they belong to adrenergic, sympathetic nerves. No membrane specializations could be detected at sites of close contact of the adrenergic boutons with dendrites and cell bodies of intrinsic nerve cells.Supported by grants from the Deutsche Forschungsgemeinschaft.Supported by a grant from Albert Pahlsson's Foundation, Sweden. The work was carried out within a research organization sponsored by the Swedish Medical Research Council (projects No. B70-14X-1007-05B, B70-14X-712-05, and B70-14X-56-06).