ALBERT — All Library Books, journals and Electronic Records Telegrafenberg

11

Electronic Resource

Melanin-concentrating hormone-like immunoreactive material in the rat hypothalamus; characterization and subcellular localization (1988)

Naito, Nobuko ; Kawazoe, Ichiro ; Nakai, Yasumitsu ; [et al.]

Springer

Cell & tissue research 253 (1988), S. 291-295

add to mindlist on the mindlist

Details

ISSN: 1432-0878

Keywords: Melanin-concentrating hormone (MCH) ; Hypothalamus ; Melanin-concentrating activitiy ; Radioimmunoassay ; Immunocytochemistry ; Rat (Wistar)

Source: Springer Online Journal Archives 1860-2000

Topics: Biology , Medicine

Notes: Summary Melanin-concentrating hormone (MCH) is a neurosecretory peptide that induces melanin concentration within teleost melanophores. Here, we characterized MCH-like substance in the rat brain by both an in vitro fish-scale melanophore bioassay and a radioimmunoassay with a salmon MCH antiserum that is directed toward the carboxy-terminus and requires the cyclic configuration for recognition. Furthermore, subcellular localization of the MCH in the rat brain was examined by immunocytochemistry using electron microscopy. We confirmed that MCH-immunoreactivity and MCH-bioactivity were present together in the same effluent fractions of the rat hypothalamic extracts by reverse-phase high-performance liquid chromatography (HPLC). At electron microscopic level, MCH-immunoreactivity was located specifically in secretory granules in MCH-positive cell bodies confined to the hypothalamus with their neuronal processes projecting widely in the rat brain. Although full characterization of substance must await its isolation, our results strongly support the notion that rat MCH-like substance may be homologous but not identical to salmon MCH, and simultaneously may serve some neurotransmitter and/or neuromodulator role in the brain of the rat.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/BF00222284

Permalink

	Location	Call Number	Expected	Availability

Others were also interested in ...

Paper (German National Licenses)

Fulltext

12

Electronic Resource

Differential production and regulation of gonadotropins (GTH I and GTH II) in the pituitary gland of rainbow trout, Oncorhynchus mykiss, during ovarian development (1991)

Naito, Nobuko ; Hyodo, Susumu ; Okumoto, Naoto ; [et al.]

Springer

Cell & tissue research 266 (1991), S. 457-467

add to mindlist on the mindlist

Details

ISSN: 1432-0878

Keywords: Gonadotropin ; Gonadotropin subunits ; Gonadotropes ; In situ hybridization ; Immunocytochemistry ; Pituitary gland, pars distalis ; Oogenesis ; Oncorhynchus mykiss (Teleostei)

Source: Springer Online Journal Archives 1860-2000

Topics: Biology , Medicine

Notes: Summary Biosynthesis of salmon gonadotropins, GTH I and GTH II, during ovarian development, were examined by means of in situ hybridization histochemistry and indirect immunocytochemistry. In rainbow trout pituitary glands, expression of GTH Iβ- and IIβ-subunit genes appeared separately in distinct cells (GTH I- and GTH II-cells), whereas the GTH α-subunit gene was expressed in both cell-types. In the GTH I-cells, coordinated increases in GTh, α and Iβ messenger ribonucleic acids (mRNAs) occurred coincident with the onset of vitellogenesis, indicating active synthesis of GTH I during vitellogenesis. In contrast, in the GTH II-cells, both GTH α-and IIβ-mRNA signals markedly increased from a later stage of vitellogenesis and persisted throughout oocyte maturation and ovulation, supporting the idea that GTH II is actively synthesized as a maturational GTH. GTH α-mRNA levels in the GTH I-cells selectively decreased prior to final oocyte maturation, although Iβ-mRNA levels remained elevated, thus suggesting a decline of biosynthesis of GTH I after vitellogenesis. These findings clarify how the synthesis of GTH I and GTH II are coordinated in the piscine pituitary, and indicate that the expression of GTH subunit genes during gametogenesis is regulated differentially in a cell-specific manner, both temporally and spatially.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/BF00318586

Permalink

	Location	Call Number	Expected	Availability

Others were also interested in ...

Paper (German National Licenses)

Fulltext

13

Electronic Resource

Ontogeny of pituitary cell-types and the hypothalamo-hypophysial relationship during early development of chum salmon, Oncorhynchus keta (1993)

Naito, Nobuko ; Jesus, Evelyn Grace ; Nakai, Yasumitsu ; [et al.]

Springer

Cell & tissue research 272 (1993), S. 429-437

add to mindlist on the mindlist

Details

ISSN: 1432-0878

Keywords: Pituitary gland ; Cell-types ; Hypothalamoneurohypophysial system ; Immunocytochemistry ; Oncorhynchus keta (Teleostei)

Source: Springer Online Journal Archives 1860-2000

Topics: Biology , Medicine

Notes: Abstract The ontogeny of pituitary cell-types, hypothalamic neurons and their fibers, was studied immunocytochemically during development of chum salmon. Five weeks after fertilization (eyed stage embryos), 5 cell-types were detected in the adenohypophysial (AHP) anlage; prolactin (PRL)-, growth hormone (GH)-, adrenocorticotropin (ACTH)-, melanotropin (α-MSH)-, and thyrotropin (TSH)-producing cells. The PRL-, GH- and ACTH-cells were relatively well developed as compared with MSH- and TSH-cells. Gonadotropes, however, were not detected even 3 weeks after hatching (10 weeks after fertilization). The neurohypophysis (NHP), on the other hand, began to grow around the eyed stage. Neuroendocrine fibers, not only from the tuberal hypothalmus (melanin-concentrating hormone) but also from the preoptic regions (vasotocin and somatostatin), reached the NHP during the last week of embryonic life. In the developing pituitary, the ratio between the length of the boundary between the AHP and the NHP, and the area of the AHP, was stable, being approximately 1–4%. The coordinated development of the AHP and NHP in chum salmon seems to result in the development of the characteristic hypothalamo-hypophysial relationship by the time of hatching.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/BF00318549

Permalink

	Location	Call Number	Expected	Availability

Others were also interested in ...

Paper (German National Licenses)

Fulltext

14

Electronic Resource

Sites of expression of mRNA for lysenin, a protein isolated from the coelomic fluid of the earthworm Eisenia foetida (2000)

Ohta, Naoshi ; Shioda, Seiji ; Sekizawa, Yoshiyuki ; [et al.]

Springer

Cell & tissue research 302 (2000), S. 263-270

add to mindlist on the mindlist

Details

ISSN: 1432-0878

Keywords: Chloragocyte In situ hybridization Lysenin Typhlosole Earthworm, Eisenia foetida (Annelida)

Source: Springer Online Journal Archives 1860-2000

Topics: Biology , Medicine

Notes: Abstract. Lysenin is a 33-kDa protein of 297 amino acids that was originally purified from the coelomic fluid of the earthworm Eisenia foetida. It binds specifically to sphingomyelin. In this study, we attempted to identify the site of synthesis of lysenin in the earthworm. We detected the expression of mRNA for lysenin and the presence of immunoreactive lysenin in the large coelomocytes and in the free large chloragocytes present in the lumen of the typhlosole, a depression in the dorsal wall of the intestine. These coelomocytes and chloragocytes seemed to be mature and separate from the chloragogen tissue that lined the typhlosole. The free large chloragocytes in the typhlosole contained numerous vacuoles. The nuclei were small and irregular in shape, and glycogen granules and mitochondria were occasionally found between vacuoles. The chloragocytes of the chloragogen tissue that surrounded the coelomic side of the intestine and the dorsal blood vessel did not react with the lysenin antiserum and no expression of lysenin mRNA was detected in these cells. Furthermore, no evidence of the protein or of the mRNA was found in the cells of the pharyngeal gland. Our findings suggest that lysenin is produced in the free large chloragocytes in the lumen of the typhlosole.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/s004410000284

Permalink

	Location	Call Number	Expected	Availability

Others were also interested in ...

Paper (German National Licenses)

Fulltext

15

Electronic Resource

Ultrastructural characteristics of two distinct gonadotropes (GTH I- and GTH II-cells) in the pituitary of rainbow trout Oncorhynchus mykiss (1993)

Naito, Nobuko ; Suzuki, Kunimasa ; Nozaki, Masumi ; [et al.]

Springer

Fish physiology and biochemistry 11 (1993), S. 241-246

add to mindlist on the mindlist

Details

ISSN: 1573-5168

Keywords: gonadotropins ; gonadotropin subunits ; gonadotropes ; lysosome ; immunocytochemistry ; Oncorhynchus mykiss

Source: Springer Online Journal Archives 1860-2000

Topics: Biology

Description / Table of Contents: Résumé L'hypophyse des salmonidés produit deux gonadotropines (GTHI et GTHII) chimiquement distinctes. Les caractéristiques ultrastructurales des cellules produisant la GTHI et la GTHII ont été étudiées par immunocytochimie en microscopie électronique en utilisant des anticorps dirigés contre les sousunités GTHIβ et GTHIIβ de saumon. Chez les poissons en vitellogenèse, les cellules à GTHI se caractèrisent par un réticulum endoplasmique granulaire (REG) contenant de nombreuses citernes dilatées et un petit nombre de granules positives à la GTHIβ (diamètre 100–300 nm) tandis qu'une immunoréactivité à la GTHII était trouvée sur des granules (diamètre 200–4000 nm) et de grands globules (diamètre 500–4000 nm) dans des cellules apparemment différentes (cellules à GTHII). Des distributions cellulaires distinctes de la GTHI et la GTHII se sont maintenues à des stades plus avancées de la gamétogenèse, bien que les caractéristiques morphologiques des cellules à GTHI et GTHII se recoupent suite à des changements dans le nombre et la taiile des granules, des globules et des citernes du REG. II est à remarquer que les globules prśents dans les cellules à GTHI étaient immunonégatifs à la GTHIβ alors que dans les cellules à GTHII ils étaient toujours marqués par l'anticorps contre la GTHIIβ. Ces résultats confirment que, dans l'hypophyse des salmonidés, les GTHIβ et GTHIIβ sont synthetisées dans des types cellulaires différents et indiquent que des caractéristiques morphologiques ne peuvent être utilisées pour distinguer ces deux types cellulaires.

Notes: Abstract The salmonid pituitary produces two chemically distinct gonadotropins (GTHI and GTHII). Ultrastructural characteristics of GTHI- and GTHII-producing cells were studied in the trout pituitary with electronmicroscopic immunocytochemistry using antisera against salmon GTHIβ- and IIβ-subunits. In pituitaries from vitellogenic fish, GTHI-cells were characterized by numerous dilated cisternae of the granular endoplasmic reticulum (GER) and a small number of Iβ-positive granules (diameter, 100–300 nm), whereas GTHIIβ-immunoreactivity was found on granules (diameter, 200–400 nm) and large globules (diameter, 500–4000 nm) in apparently different cells (GTHII-cells). Distinct cellular distributions of GTHI and GTHII were maintained during gametogenesis, although morphological characteristics of GTHI- and GTHII-cells overlapped each other due to changes in number and size of the granules, globules and cisternae of the GER. Interestingly, the globules in the GTHI-cells were immunonegative for GTHIβ, although in the GTHII-cells they were always stained with GTHIIβ-antiserum. These results confirm that GTHIβ and GTHIIβ are synthesized in distinctly different cell-types in the salmonid pituitary and indicate that morphological characteristics cannot be used to distinguish these two cell-types.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/BF00004571

Permalink

	Location	Call Number	Expected	Availability

Others were also interested in ...

Paper (German National Licenses)

Fulltext

16

Electronic Resource

Fine structure of ependymal cells in the median eminence of the frog and mouse revealed by freeze-etching (1977)

Nakai, Yasumitsu ; Ochiai, Hidehiko ; Uchida, Mieko

Springer

Cell & tissue research 181 (1977), S. 311-318

add to mindlist on the mindlist

Details

ISSN: 1432-0878

Keywords: Ependymal cells ; Median eminence ; Freeze-etching ; Frog ; Mouse

Source: Springer Online Journal Archives 1860-2000

Topics: Biology , Medicine

Notes: Summary Freeze-etched preparations of the ventricular surfaces of ependymal cells clearly reveal the presence of pinocytotic vesicles opening into the third ventricle and large vacuoles formed by broad cell projections. The density of the vesicular openings is approximately 20 per μm2. The ependymal cells in the median eminence of the frog are adjoined by tight junctions comprised of five to eight interconnected junctional strands, whereas near the median eminence in the mouse only one to two such strands form the tight junction of the ependymal cells. Gap junctions between the adjacent ependymal cells are detected near the median eminence in the mouse but not in the frog.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/BF00223106

Permalink