Vergleichende fluoreszenzmikroskopische und elektronenmikroskopische Untersuchungen am zentralen Nervensystem von Planorbarius corneus L. (Basommatophora)

Zusammenfassung Durch Vergleich fluoreszenz- und elektronenmikroskopischer Untersuchungen am zentralen Nervensystem von Planorbarius corneus L. wird nachgewiesen, daß in den Schlundringganglien Neurosekretzellen vorkommen (Nachweis mit Pseudoisocyaninchlorid), die mit Nervenzellen nicht identisch sind, die durch ihren hohen Gehalt an biogenen Aminen auffallen (Nachweis durch die Methode von Falck und Owman, 1965). Es können daher im Schlundring von Planorbarius corneus peptiderge und aminerge Neurosekretzellen unterschieden werden. Die PSC-positiven Neurosekretzellen enthalten elektronendichte Elementargrana und die aminergen Neurone dense-core Vesikel. Der Nachweis biogener Amine in einigen Nervenzellen von Planorbarius corneus spicht für deren chemische Identität mit Transmittersubstanzen, ihre hohe Konzentration aber für eine Abgabe in die Körperflüssigkeit.

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Comparative fluorescence- and electron microscopic studies of the central nervous system of Planorbarius corneus L. (Basommatophora)

Summary The neurosecretory system of the snail Planorbarius corneus has been investigated by fluorescence and electron microscopy. With the fluorochrome Pseudoisocyanin the established neurosecretory system in the cerebral ganglia and single neurosecretory cells in the other ganglia show an intensive yellow fluorescence. Electron micrographs reveal the presence of electron dense granules (elementary granules) in the pericarya and the axons of neurones which have the same localisation in the ganglia as the pseudoisocyanin-positive cells. The fluorescence technique for biogenic amines produces yellow and green fluorescence within neurons and in the neuropil and nerves. The fluorescence obtained in determinable areas and neurones correlates well with the electron microscopic location of dense-core vesicles within the pericarya and axons of cells in even the same areas. It is discussed, that in this animal both types of cells are so-called neurosecretory cells, because the high content of elementary granules in the peptidergic neurosecretory cells and of dense-core vesicles in the aminergic neurosecretory cells is an indication for secretion of these products in neurohaemal areas (circulatory channels).

     

Possible sites of release of neurosecretory granules in the sinus gland of the crayfish,Orconectes nais

Summary The sinus gland is a neurohemal organ located in the crayfish eyestalk and represents a storage site for neurohormones prior to their release into the circulation. The sinus gland contains three classes of electron dense, membrane-limited granules. Class 3 granules are the largest and most electron dense of the granules found in the sinus gland. Granules of class 1 are the smallest, while those of class 2 are the most abundant. Generally, all granules undergo similar changes during their release.Release of neurosecretory material may be initiated by a preliminary fragmentation of the parent granules into smaller granules. Following the formation of numerous smaller granules, these move to the plasma membrane and their limiting membrane apparently fuses with it thus releasing its contents into the external lamina which is applied to the sinusoidal surface of the axon terminals. Granule release does not appear to occur along the entire plasma membrane adjacent to the blood sinus but, instead, probably occurs only at specific active sites on the membrane. The active sites are characterized in part by an accumulation of small granules and clear vesicles against the cytoplasmic side of the plasma membrane. At the site of release of the neurohormone, there is often an accumulation of dense homogeneous material beneath the axolemma.Occasionally, axon endings filled with large, electron lucent vesicles are seen. These clear granules vary from 1150–1750 Å in diameter and often exhibit broken limiting membranes. Few small vesicles are seen near the plasma membrane of these endings; however, instances of invaginations of the plasma membrane occur. The significance of endings filled with clear granules is discussed.Supported by a grant from the National Research Council of Canada (No. A-4675).     

Isospora lutrae n. sp. (Apicomplexa: Eimeriidae), a new coccidium from the European otter Lutra lutra (L.) (Carnivora: Mustelidae) from Spain

Parasitological examination of European otter originating from Extremadura, Spain revealed the presence of a new isosporan species. Oöcysts of Isospora lutrae n. sp. are spherical to subspherical, 31.2 (27.5–32) × 29.6 (28–31) m and have a smooth wall c. 1 m thick. Sporocysts are ellipsoidal, 18.2 (17–19) × 14.4 (14–16) m and lack Stieda and substieda bodies. A spherical sporocyst residuum is present, consisting of granules scattered among the sporozoites. Sporozoites are spindle-shaped, 12.4 × 2.5 m and have anterior and posterior refractile bodies. Based on its unique morphologic structure and host, I. lutrae is considered to be new.     

Effects of background adaptation on α-MSH and β-endorphin in secretory granule types of melanotrope cells of Xenopus laevis

Placing the clawed toad Xenopus laevis on a black background stimulates the melanotrope cells in the pars intermedia of the pituitary gland to release proopiomelanocortin (POMC)-derived peptides, including -MSH and N-acetyl-endorphin. In this study three types of secretory granules, electron-dense(130 nm Ø), moderately electron-dense ( 160 nm Ø) and electronlucent ( 180 nm Ø), have been identified in these cells. Apparently, only dark granules are formed by the Golgi apparatus and lucent granules release their contents via exocytosis. Immuno-electron microscopy (immunogold double labelling) of glutaraldehyde-fixed and freeze-substituted material shows that desacetyl--MSH and N-acetyl--endorphin coexist in all three granule types. Quantification of immunostaining revealed that immunoreactivities to these peptides are lowest in the dark granules and highest in the light ones. It is proposed that intragranular processing of POMC to immunoreactive desacetyl--MSH and N-acetyl--endorphin involves an increase in granule size and a decrease in granule electron density. Black background-induced activation of the melanotrope cell is reflected by an increase in immunoreactivity of the secretory granules to each of the antisera. This suggests that cell activation stimulates the formation of peptides by intragranular processing of POMC and/or of intermediate POMC-processing products. In addition, cell activation evoked an increase in the percentage of the granule population that reacts with anti-N-acetyl--endorphin, probably by stimulating intragranular acetylation of -endorphin. Apparently, this acetylation is a regulated event that occurs in the cytoplasm, independently from the acetylation of desacetyl--MSH which takes place near the plasmalemma at the time of granule exocytosis.     

The hypothalamo-hypophysial system in acipenseridae

Summary Neurohypophyses of sexually mature Acipenser güldenstädti Brandt and Acipenser stellatus Pallas maintained in hypertonic solutions were studied by means of light and electron microscopy. The fish were caught in the Ural and transferred into basins containing either freshwater (controls) or 32, 22 and 17 NaCl solutions respectively. The neurohypophyses of control animals kept in freshwater for two days contained a large amount of Gomori-positive neurosecretory material (4 arbitrary units). An abundance of neurosecretory granules of different kinds, predominantly elementary ones, was observed electron microscopically in neurosecretory fibres and terminals of these fish. A decrease in the amount of neurosecretory material was found in all experimental animals: up to 1–2 units in A. güldenstädti after 3.5–10 h in 32 NaCl, and up to 3.5 units in A. stellatus after 4.5–48 h in 22 or 17 NaCl. The number of neurosecretory granules decreased considerably in the fibres and terminals in all experimental series, but that of granulated, disintegrating granules and granule-shadows increased markedly, especially in preterminal parts of axons. An increased number of hypertrophied mitochondria, lamellar bodies, residual granules and especially synaptic vesicles was seen. These changes speak for an active discharge of neurohormones into the general circulation, a phenomenon well known to be characteristic of stress responses. Pathological ultrastructural changes (breakdown of terminals, extracellular wide cisternae) were visible in A. güldenstädti neurohypophyses at the end of the experiments. Also tanycytes — narrow ependymal cells — and pituicytes underwent noticeable changes.We wish to express our deep appreciation to the Director of the Guriev Branch of the Institute of Sturgeon Industry, N. E. Peseridi, M. Sc. Biol., for very valuable help in making this study possible.     

Ultrastructural development of the neurohemal organ joined to the ecdysial gland after imaginal moulting in the male isopod Sphaeroma serratum fab. (Crustacea Flabellifera)

Summary The present ultrastructural study deals with the lateral cephalic nerve plexus of Sphaeroma serratum, a neurohemal organ joined to the Y organ (ecdysial gland). This plexus acts as a storage centre for neurosecretory products from two sources: the two autochtonous cells (plexus cells) within the plexus itself, and the neurosecretory cells in various parts of the central nervous system, particulary the mandibular ganglion (A-cells).In prepuberal animals, plexus cells and subesophageal A-cells produce neurosecretory granules of two types measuring 1550±50Å and 1570±40Å respectively. Five categories of axon terminals were distinguished in the plexus. The granules found in two of these terminal types are believed to come from the plexus cells and from the mandibular ganglion A-cells.Cessation of production of neurosecretory granules in these A cells and plexus cells was observed in puberal animals, in the plexus with concomitant depletion and disappearance of different granule categories. The first axon terminals affected by this process are the two categories containing granules originating in the plexus and mandibular ganglion A-cells. Degeneration of the ecdysial gland in male Sphaeroma serratum might be connected with the cessation of granule formation in these two types of cell.

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Résumé Chez Sphaeroma serratum, la mue de puberté est suivie d'une dégénérescence de l'organe Y (glands de mue). Le plexus nerveux céphalique latéral, organe neurohémal accolé à cette glande a été l'objet de la présente étude ultrastructurale. Cet organe représente un centre de stockage de neurosécrétions qui proviennent d'une part, de deux cellules autochtones (cellules plexales) situées au sein même de ce plexus, d'autre part, de cellules neurosécrétrices situées dans le ganglion mandibulaire (cellules de type A).Chez les individus pubères, les cellules plexales et les cellules A du ganglion sous-oesophagien synthétisent des granules de neurosécrétion dont la taille est respectivement 1550±50Å et 1570±40Å. Il a été reconnu au sein du plexus 5 catégories de terminaisons dont les granules proviendraient pour deux d'entre elles des cellules plexales et des cellules A du ganglion mandibulaire. Chez les animaux pubères on observe un arrêt de la synthèse des granules de neurosécrétion au sein des cellules plexales et des cellules A du ganglion mandibulaire. Simultanément on enregistre dans le plexus la raréfaction puis la disparition des divers types de granules. Ce processus atteint en premier les terminaisons correspondant aux cellules plexales et aux cellules A du ganglion mandibulaire. La dégénérescence de la glande de mue chez les mâles pourrait être en relation avec l'arrêt de synthèse de ces cellules.

     

Histochemical investigations on the human fetal subcommissural organ

Summary A histochemical and ultrastructural study was carried out on subcommissura organs from 42 human embryos and fetuses in order to characterize some large granulesTypical granules make their appearance in the rostral hypendymal region of the subcommissural organ (SCO) in fetuses of about 50 mm CRL. Although they appear in other SCO-regions later, the highest number of granules is always located towards the pineal gland.Typical granules are of spherical shape with a diameter of about 2 microns. The various histochemical reactions reveal a reactivity which differentiates the shell of the granules from the granule interior. Nucleoproteins are present in the shell together with phospholipids and/or lipoproteins. The interior of the granules can contain different materials such as glycogen or lipid or neurosecretory substance. Ultrastructural observations show that a granule consists of whorls of endoplasmic reticulum sparsely studded with ribosomes surrounding an interior containing either lipid or lipoprotein inclusions, large amounts of glycogen or simply cytoplasm.It is suggested that the concentric lamellar organelle (CLO) is a morphological entity that might be involved in secretory processes rather than being the secretory granules themselves.This work was supported by a grant from Statens almindelige Videnskabsfond, Copenhagen.     

Immunocytochemical identification of neuroendocrine markers in human cardiac paraganglion — like structures

Summary Paraganglion-like structures (PLS) containing chromaffin-positive cells have been reported to be present in the adult human heart. The present work was initiated in order to evaluate the densitity of these structures in the interatrial septum and to study the presence of immunoreactivity of their cells to NSE and PGP 9,5 antibodies, two neuroendocrine markers. Six hundred 6-m paraffin serial sections were obtained from the upper third of the interatrial septum from six adult human hearts. From 2 to 12 paraganglia were found in each case, and their principal cells stained positively with NSE and PGP 9,5 antibodies. Depending on how these PLS related to other cardiac structures, four different types were identified: Type I — True paraganglia (located adjacent to ganglia or nerve fibers); Type II — Free paraganglia (immersed in the interatrial adipose tissue, without evident connection to other structures); Type III — Intraganglionic paraganglia (located within the nervous ganglia); Type IV — Intramyocardic paraganglia (small nests of immunoreactive cells closely related to myocardiocyte bundles). These cardiac paraganglia, which probably belong to the visceral-autonomic group, may have a role in the regulation of the cardiac function and in the adaptive mechanisms of the heart. Its is also possible that they originate functioning and non-functioning tumours.Work supported by grants from FINEP and CNPq (Brazil)     

The pancreatic islets of the teleost Scorpaena scropha

Summary The principal pancreatic islets of the teleost Scorpaena scropha are found ultrastructurally to contain four different kinds of parenchymal cells, viz. ₁-(= D), ₂-, -and agranular cells. The -cells show considerable variations in the shape of the secretory granules. A peculiar feature is that many of these granules are composed of fibrillar subunits, often in parallel arrangement. All -granules are surrounded by membranes and between the membrane and the granule core there is a moderately wide electron lucent space. The electron density of the cytoplasm in the -cells varies somewhat. The ₂-cells possess typical secretory granules with an electron dense core and a closely applied membrane. The secretory granules in the ₁-cells show also a closely applied membrane but a less dense core. Also in the -cells the electron opacity of the cytoplasm varies. The agranular cells are mainly characterized by low cytoplasmic electron density, narrow cisterns of endoplasmic reticulum and sometimes a laminated Golgi complex. Small immature secretory granules are occasionally seen in the cytoplasm of these cells. The significance of the fibrillar -granules remains obscure.This work was supported by grants from the Nordic Insulin Fund, the Town of Umeå, the Swedish Medical Research Council (Project No. B69-12X-718-04A), and by a postdoctoral fellowship from the United States Public Health Service.     

Postnatal development of the intrinsic nervous system in the circumvallate papilla-vonEbner gland complex

We have studied the postnatal development of the intrinsic nervous system in the circumvallate papilla–vonEbner gland complex using NADPH-diaphorase cytochemistry, immunocytochemistry (for nitric oxide synthase-1 and -internexin) and electron microscopy. In rats sacrificed in their first day post partum (1p.p.), only isolated NADPH-diaphorase positive neurons were visible in the organ. At 2p.p., a small group of neurons was visible at the base of the papillae and positive neurons formed short chains close to the developing glandular tubules. In the following days, the NADPH-diapharase positive cells increased in number and nerve fibres were associated to small ganglia located at the base of the papilla or in the gland. After the first week of extrauterine life, the intrinsic nervous system was similar to the intrinsic system of adult animals. An immunocytochemical positivity for nitric oxide synthase-1 appeared at 4p.p. in neurons located in the gland and at 7p.p. in cells located at the base of the papilla. Immunocytochemical staining for -internexin showed that at 1p.p. developing nerve fibres were present in the connective tissue of the tongue's muscle layer. At 2–3p.p., developing nerve fibres were also present at the bases and in the core of the papilla. In the following days, the positivity for -internexin was reduced and one week after birth was virtually absent. Ultrastructural examination revealed that since 1p.p. isolated neurons can be found at the base of the papilla. In conclusion, the intrinsic nervous system originates from neurons present in the organ at the birth which, in the first days, undergo a biochemical and morphological maturation while the nerve fibres rapidly grow. These findings support the hypothesis that the intrinsic nervous system of the circumvallate papilla has a role in the maturation of the vonEbner gland.     

The cytology of phytophthora infestans

Summary Phytophthora infestans has three kinds of somatic nuclei: an oval shaped nucleus (approx. 3.1×2.7 ) which stains diffusely except for a crescent shaped Feulgen positive cap which stains intensely; a granular nucleus whose contents are organized into a fairly constant number of stained bodies, and, a deeply staining condensed nucleus. The capped nucleus is thought to be metabolic or resting and the granular nucleus is thought to be dividing as it is most commonly found in hyphal tips. Attenuated forms of all three kinds of nuclei are found.Nuclear division is mitotic and intranuclear. Eight—ten chromosomes are seen at metaphase.Sporangia have a mean of 6.3 nuclei which is constant for age and strain of culture. Sporangia become multinucleate as a result of nuclear migration and not by division in the developing sporangium. Zoospores are usually uninucleate.The nuclear cap is persistent throughout nuclear division when it also divides. It is associated with flagella production and nuclear migration and has some of the properties of a blepharoplast.     

Ultrastructure of the rat posterior pituitary gland and evidence of hormone release by exocytosis as revealed by freeze-fracturing

Summary Posterior pituitary glands from normal rats, and rats which had been deprived of water for varying periods, were examined by the freeze-fracture method. This technique reveals large areas of the nerve cell membrane. Images consistent with exocytosis as the mechanism of release of the neurohypophysial hormones were observed. These modifications were most numerous after the rat had been starved of water for 2 days.In normal rats, the large number of neurosecretory granules within the nerve fibres caused a bulging of the nerve cell membrane. The bulges disappeared 2 days after removal of drinking water. Regions of the membrane displaying bulges were characterised by the absence of the typical membrane-associated particles.It is postulated that the close proximity of the neurosecretory granules to the nerve cell membrane may result in rapid fusion of the neurosecretory granules on stimulation of the gland. The change in properties of the nerve cell membrane overlying the neurosecretory granules, as suggested by the loss of membrane-associated particles, may represent a change in the structure of the membrane to a form which is more favourable for fusion.This work was supported in part by a grant from the New Zealand Medical Research Council.     

Enzymic synthesis of the trisaccharide core region of the carbohydrate chain ofN-glycoprotein

Transmannosylation from mannotriose (Man1-4Man1-4Man) to the 4-position at the nonreducing end N-acetylglucosaminyl residue ofN,N-diacetylchitobiose was regioselectively induced through the use of -d-mannanase fromAspergillus niger. The enzyme formed the trisaccharide Man1-4GlcNAc1-4GlcNAc (3.7% of the enzyme-catalysed net decrease ofN,N-diacetylchitobiose) from mannotriose as a donor andN,N-diacetylchitobiose as an acceptor. Mannobiose (Man1-4Man) was also shown to be useful as a donor substrate for the desired trisaccharide synthesis.Abbreviations Man d-mannose - (M _n) (n=1–5) -linkedn-mer of mannose - GlcNAc₂ 2-acetamido-2-deoxy--d-glucopyranosyl-(1–4)-2-acetamido-2-deoxy-d-glucose     

Evidence of regional differences in the lectin histochemistry along the ductus epididymis of the lizard,Podarcis sicula Raf

The regional difference in the carbohydrate components of the ductus epididymis epithelium of a lizard was delineated by means of 13 lectins. Basal cells expressed only N-acetylglucosamine (GlcNAc). Throughout the ductus, the secretory cells showed oligosaccharides with terminal N-acetylneuraminic acid (Neu5Ac)(2,6)galactose (Gal)/N-acetylgalactosamine (GalNAc) and internal mannose (Man) and/or glucose (Glc) in the whole cytoplasm, oligosaccharides terminating in Neu5Ac(2,6)Gal(1,3)GalNAc, Neu5Ac(2,6)Gal (1,4)GlcNAc, GalNAc, GlcNAc, and fucose (Fuc) in the supra-nuclear zone, and also glycans terminating in Neu5Ac(2,3)Gal (1,4)GlcNAc, Neu5Ac(2,6)Gal(1,3)GalNAc, Gal (1,4)GlcNAc on the luminal surface. In the caput and corpus regions, the supra-nuclear cytoplasm was characterized by terminal Gal(1,4)GlcNAc and GalNAc, the luminal surface by GalNAc and Gal. The Golgi zone, showing oligosaccharides with terminal Neu5Ac(2,3)Gal (1,4)GlcNAc, Neu5Ac(2,6)Gal (1,3)GalNAc, Neu5Ac(2,6)Gal (1,4)GlcNAc, and internal GlcNAc, expressed terminal Gal (1,4)GlcNAc and GalNAc in the caput, and terminal GalNAc in the corpus. The granules showed all the investigated carbohydrates in their peripheral zone except terminal GalNAc and Fuc, whereas internal Man/Glc and terminal Gal were expressed in the central core, and Fuc throughout the ductus, terminal GlcNAc in the caput and corpus, and terminal GalNAc only in the corpus.     

The mechanism of object fixation and its relation to spontaneous pattern preferences in Drosophila melanogaster

The orientation behavior of walking flies, Drosophila melanogaster, towards a single 6° wide black vertical stripe (elementary stripe) can be explained by use of the turning tendency function H(). This function is characterized by maximal values at an angular distance of =25° from the stable zero position (=orienting direction), a sharp decline from this maximum to =60°, and a very slow approach to the unstable zero position (Horn and Wehner, 1975). The shape of this function is influenced by both translatory and rotatory components of movement. If the translatory component is minimized by measuring the turning function W() (see 2.3) at a distance of 10 mm (C1) from the center of the arena, a change in the strength of this decline is caused. But with increasing translatory component, i.e. at a greater distance from the center of the arena, W() approximates the heuristical function H() (Fig. 12). The turning functions W() are pattern-specific; the angular positions of the maximum responses shift to greater angles with increasing width of the patterns (Fig. 2). In the twopattern configuration with double or single stripes, there is always a coincidence between the stable zero positions of W (), the mean of the frequency distributions P() of the flies' positions and n _g() of the straight courses, and the stable zero positions of H () obtained from an additive superposition of two or more angular shifted turning tendency functions H() (Fig. 5, 7). Therefore, the mean positions of the flies in a multi-stripe experiment composed of elementary stripes can be predicted from the addition of many angular shifted turning tendency functions H(). Between H() and the frequency distribution P() of the flies' positions , the following formula holds: P() =C·H()d (Fig. 13). With this equation, the spontaneous preference of the broader of two double stripes can be explained presuming lateral interactions between the components of the patterns (Fig. 8, 10). The strength x _i ^* of this lateral interaction depends on the width of the double stripes. The greater , the smaller is x _i ^* . x _i ^* is a pattern-specific value (Table 1, 2).Supported by the Deutsche Forschungsgemeinschaft, Ho 664/2     

Modulation of brain mitochondrial membrane permeability and synaptosomal Ca2+ transport by dopamine oxidation

Effects of dopamine on the membrane permeability transition, thioredoxin reductase activity, production of free radicals and oxidation of sulfhydryl groups in brain mitochondria and the Ca²⁺ uptake by Na⁺-Ca²⁺ exchange and sulfhydryl oxidation in brain synaptosomes were examined. The brain mitochondrial swelling and the fall of transmembrane potential were altered by pretreatment of dopamine in a dose dependent manner. Depressive effect of dopamine on mitochondrial swelling was reversed by 10 g/ml catalase, and 10 mM DMSO. The activities of thioredoxin reductase in intact or disrupted mitochondria were decreased by dopamine (1-100 M), 25 M Zn²⁺ and 50 M Mn²⁺. Dopamine-inhibited enzyme activity was reversed by 10 g/ml SOD and 10 g/ml catalase. Pretreatment of dopamine decreased Ca²⁺ transport in synaptosomes, which was restored by 10 g/ml SOD and 10 mM DMSO. Dopamine (1-100 M) in the medium containing mitochondria produced superoxide anion and hydrogen peroxide, while its effect on nitrite production was very weak. The oxidation of sulfhydryl groups in mitochondria and synaptosomes were enhanced by dopamine with increasing incubation times. Results suggest that dopamine could modulate membrane permeability in mitochondria and calcium transport at nerve terminals, which may be ascribed to the action of free radicals and the loss of reduced sulfhydryl groups.     

Observations on the fine structure of the cercaria of Notocotylus attenuatus and formation of the cyst wall of the metacercaria

Summary The dorsal tegument of the mature cercaria of Notocotylus attenuatus is a syncytial, cytoplasmic layer, containing two types of secretory granule which are identifiable ultrastructurally. The type 1 secretory bodies are electron lucid, whereas most type 2 granules have a banded appearance. The ventral tegument contains granules which are secreted from the type 3 cells; the type 3 granules are membrane bound, electron dense, and consist of both an amorphous and a finely striated zone. The type 4 cells mainly contain cigar-shaped granules consisting of an amorphous core surrounded by concentric striations. The granules exhibit structural variability in shape and content. The type 4 cells undergo a cellular migration to the tegument during encystment. The structure of the posterior-lateral glands and mode of secretion of the granules are described. Possible functions of microtubules are discussed for each cell type. Details of some secretory processes involved in the formation of the hemispherical cyst wall are described. The layers of the cyst wall may be related to the granular contents of the various parenchymal cells of the cercaria. The tegument of the metacercaria originates primarily from the cytoplasm of the type 1, type 2, type 3 and type 4 cells.     

Intra- and extraganglionic nerve endings formed by neurosecretory cells of the cerebral ganglion of the earthworm (Lumbricus terrestris L.)

Summary In the cerebral (= supraesophageal, suprapharyngeal) ganglion of the earthworm, a number of neurosecretory Gomori-positive perikarya are bipolar; others are unipolar, or multipolar. Some of the neurosecretory cell processes project centrally into a fibrous zone; peripheral processes enter small nerves which leave the dorsocaudal aspect of the ganglion.In the central fibrous zone, the neurosecretory fibers form varicose Gomoripositive terminals. Here, also zinc-iodine-osmium (ZIO)-positive fibers and monoamine fluorescent fibers are found. With the electron microscope, nerve terminals containing synaptic vesicles and either large neurosecretory peptidergic granular vesicles (diameter more than 1500 Å), or smaller granular vesicles (diameter about 1300 Å, or 900 Å) are observed. These axon endings mainly form axo-dendritic synapses. Peptidergic profiles are both pre- and postsynaptic. Some of the extraganglionic peptidergic fibers appear to terminate around vessels, but most of them form terminals on the visceral muscle cells which surround the ganglion.We think that the central neurosecretory processes communicate with the fibers of the synaptic zone of the ganglion. The peripheral neurosecretory peptidergic fibers are supposed to form a primitive neurohemal area and/or to function as vasomotor nerves. The fibers innervating the visceral muscle cells may represent vegetative nerves.     

Synthesis of disaccharide derivatives employing β-N-acetyl- d-hexosaminidase, β-d-galactosidase and β-d-glucuronidase

-N-Acetyl-d-hexosaminidase from Aspergillus oryzae catalysed the stereo- and regiospecific formation of the 6-O-benzylated disaccharide derivatives GalNAc1-3(6- OBn)Gal-SEt and GlcNAc1-3(6-OBn)Gal-SEt, which were obtained in transglycosylation reactions employing ethyl 6- O-benzyl-1-thio--d-galactopyranoside as acceptor. Preparative amounts of the chitobiose derivative GlcNAc1- 3GlcNAc-OPhNO2-p was prepared as well. - N-Acetyl-d-hexosaminidase from bovine testes catalysed the specific synthesis of GlcNAc1-3(6-OBn)GlcNH2-SEt and GalNAc1-3(6-OBn)GlcNH2-SEt, employing ethyl 2-amino-6-O-benzyl-2-deoxy-1-thio--d-glucopyranoside as acceptor. -d-Glucuronidase from E. coli was found to catalyse the formation of GlcA1-3(6-OBn)GlcNH2- SEt employing the same acceptor.     

Alkaline lipolytic activity of rabbit adipose tissue: Genotypes and their inheritance

A genetic variant of alkaline lipolytic activity (ALA), a soluble esterase found in mammalian adipose tissue, has previously been described. This slow variant was characterized by slower migration during starch gel electrophoresis, a decreased tendency to dimerize, and reduced enzymatic activity in constrast to the fast electrophoretic phenotype. The present paper identifies a homozygous (FF) and a heterozygous (Ff) fast phenotype which are differentiated after starch gel electrophoresis by the presence or absence of a slow band identical to that of the homozygous slow (ff)/it phenotype. In addition, ALA of homozygous and heterozygous fast rabbits differed in total enzymatic activity and its tendency to dimerize. The inheritance of this variant was proven to be Mendelian.This work was supported in part by United States Public Health Service Grants AM-06872 from the National Institute of Arthritis and Metabolic Diseases and GM-15874 from the National Institute of General Medical Sciences; and Project #417 of the Children's Bureau, Department of Health, Education and Welfare.