Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Journal of fish biology 46 (1995), S. 0 
    ISSN: 1095-8649
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: The effect of decreased environmental salinity on growth hormone producing cells (GH cells) of the adenohypophysial proximal pars distalis has been studied in the gilthead sea bream (Sparus aurata L.) adapted to sea water (SW, 980 mosmol kg −1) and brackish water (BW, 200 mosmol kg −1). A combined immunocytochemical, morphometric and electron microscopic study was carried out. GH cells offish adapted to BW occupied a greater hypophysial volume (about 21% of the total hypophysial volume in BW, 17% in SW) and had a larger nuclear area (mean 16 μm2 in BW, 13 μm2 in SW) than GH cells of SW-adapted fish. The immunoreactivity against a salmon GH-antiserum was lower in BW (mean optical density 142 in BW, 159 in SW). Ultrastructural characteristics of GH cells of BW-adapted fish were distended rough endo-plasmatic reticulum and large secretory granules (about 216 nm in diameter for BW, 209 nm in SW). Volumetric, densitometric and ultrastructural evidence suggested that the synthesis and release of GH were activated in S. aurata adapted to hypo-osmotic environment.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1432-0568
    Keywords: Corticotropin-releasing factor (CRF) ; Immunocytochemistry ; Mauremys caspica (Chelonia)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Brain sections of the turtle, Mauremys caspica were studied by means of an antiserum against rat corticotropin-releasing factor. Immunoreactive neurons were identified in telencephalic, diencephalic and mesencephalic areas such as the cortex, nucleus caudatus, nucleus accumbens, amygdala, subfornical organ, paraventricular nucleus, hypothalamic dorsolateral aggregation, nucleus of the paraventricular organ, infundibular nucleus, pretectal nucleus, periventricular grey, reticular formation and nucleus of the raphe. Many immunoreactive cells located near the ependyma were bipolar, having an apical dendrite that contacted the cerebrospinal fluid. Immunoreactive fibers were seen in these locations and in the lamina terminalis, lateral forebrain bundle, supraoptic nucleus, median eminence, neurohypophysis, tectum opticum, torus semicircularis and deep mesencephalic nucleus. Parvocellular bipolar immunoreactive neurons from the paraventricular and infundibular nuclei projected axons that joined the hypothalamo-hypophysial tract and reached the outer zone of median eminence, and the neural lobe of the hypophysis where immunoreactive fibers terminated close to intermediate lobe cells. From these results it can be concluded that, as in other vertebrates, corticotropin-releasing factor in the turtle may act as a releasing factor and, centrally, as a neurotransmitter or neuromodulator.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1432-0878
    Keywords: Oxytocin ; Neurophysin ; Vasotocin ; Mesotocin ; Suprachiasmatic nucleus ; Medial nucleus of the infundibular recess ; Immunocytochemistry ; Natrix maura (Serpentes) ; Mauremys caspica (Chelonia)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The probable presence of oxytocin in the hypothalamo-hypophysial system of two reptilian species, the snake Natrix maura and the turtle Mauremys caspica, was re-investigated. A high-pressure liquid chromatographic analysis of the turtle neural lobe revealed the existence of vasotocin, mesotocin, and a third compound co-eluting with oxytocin. Brains from both species were fixed by vascular perfusion with Bouin's fluid. Adjacent paraffin sections were immunostained using antisera against the following substances: (1) bovine oxytocin-neurophysin; (2) a mixture of bovine oxytocin-neurophysin and vasopressin-neurophysin; (3) dogfish neurophysins; (4) oxytocin; (5) arginine-vasotocin; (6) mesotocin; (7) somatostatin. Immunoreactivity against oxytocin was found in parvocellular neurons of the snake suprachiasmatic nucleus and cerebrospinal-fluid contacting neurons of the medial nucleus of the infundibular recess of both species, the latter immunoreactivity being much more conspicuous in the turtle. Numerous fibers containing immunoreactive oxytocin extended between the medial nucleus of the infundibular recess, and the internal region of the medium eminence and the neural lobe. The oxytocin-immunoreactivity in all locations was completely abolished by preabsorption of the anti-oxytocin serum with three different oxytocin preparations. None of the neurons of the suprachiasmatic and medial nucleus of the infundibular recess, including the oxytocin-immunoreactive elements, reacted with either the antineurophysin sera used, or the anti-vasotocin or anti-mesotocin antibodies. The possible existence of a reptilian oxytocin-neurophysin is discussed. The alternative that, in the reptilian hypothalamus, neurons synthesize a compound closely related to, but different from oxytocin is also considered.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 1432-0878
    Keywords: Key words: Oxytocin ; Neurophysin ; Vasotocin ; Mesotocin ; Suprachiasmatic nucleus ; Medial nucleus of the infundibular recess ; Immunocytochemistry ; Natrix maura (Serpentes) ; Mauremys caspica (Chelonia)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. The probable presence of oxytocin in the hypothalamo-hypophysial system of two reptilian species, the snake Natrix maura and the turtle Mauremys caspica, was re-investigated. A high-pressure liquid chromatographic analysis of the turtle neural lobe revealed the existence of vasotocin, mesotocin, and a third compound co-eluting with oxytocin. Brains from both species were fixed by vascular perfusion with Bouin's fluid. Adjacent paraffin sections were immunostained using antisera against the following substances: (1) bovine oxytocin-neurophysin; (2) a mixture of bovine oxytocin-neurophysin and vasopressin-neurophysin; (3) dogfish neurophysins; (4) oxytocin; (5) arginine-vasotocin; (6) mesotocin; (7) somatostatin. Immunoreactivity against oxytocin was found in parvocellular neurons of the snake suprachiasmatic nucleus and cerebrospinal-fluid contacting neurons of the medial nucleus of the infundibular recess of both species, the latter immunoreactivity being much more conspicuous in the turtle. Numerous fibers containing immunoreactive oxytocin extended between the medial nucleus of the infundibular recess, and the internal region of the medium eminence and the neural lobe. The oxytocin-immunoreactivity in all locations was completely abolished by preabsorption of the anti-oxytocin serum with three different oxytocin preparations. None of the neurons of the suprachiasmatic and medial nucleus of the infundibular recess, including the oxytocin-immunoreactive elements, reacted with either the antineurophysin sera used, or the anti-vasotocin or anti-mesotocin antibodies. The possible existence of a reptilian oxytocin-neurophysin different from the mammalian oxytocin-neurophysin is discussed. The alternative that, in the reptilian hypothalamus, neurons synthesize a compound closely related to, but different from oxytocin is also considered.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 1432-0878
    Keywords: Key words: Melanin-concentrating hormone ; Immunocytochemistry ; Development ; ontogenetic ; Sparus auratus (Teleostei)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. The development of the hypothalamic melanin-concentrating hormone (MCH) system of the teleost Sparus auratus has been studied by immunocytochemistry using an anti-salmon MCH serum. Immunoreactive perikarya and fibers are found in embryos, larvae, and juvenile specimens. In juveniles, most labeled neurons are present in the nucleus lateralis tuberis; some are dispersed in the nucleus recessus lateralis and nucleus periventricularis posterior. From the nucleus lateralis tuberis, MCH neurons project a conspicuous tract of fibers to the ventral hypothalamus; this penetrates the pituitary stalk and reaches the neurohypophysis. Most fibers end close to the cells of the pars intermedia, and some reach the adenohypophysial rostral pars distalis. Immunoreactive fibers can also be seen in extrahypophysial localizations, such as the preoptic region and the nucleus sacci vasculosi. In embryos, MCH-immunoreactive neurons first appear at 36 h post-fertilization in the ventrolateral margin of the developing hypothalamus. In larvae, at 4 days post-hatching, perikarya can be observed in the ventrolateral border of the hypothalamus and in the mid-hypothalamus, near the ventricle. At 26 days post-hatching, MCH perikarya are restricted to the nucleus lateralis tuberis. The neurohypophysis possesses MCH-immunoreactive fibers from the second day post-hatching. The results indicate that MCH plays a role in larval development with respect to skin melanophores and cells that secrete melanocyte-stimulating hormone.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    ISSN: 1432-0878
    Keywords: Hypothalamus ; Neurosecretion ; Vasotocin-neurophysin precursor ; Immunocytochemistry ; Lectin histochemistry ; Snake, Natrix maura ; Lizard, Liolaemus cyanogaster
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The immunocytochemical and lectin-binding properties of the magnocellular neurosecretory neurons in the hypothalamus of 2 reptilian species, the snake Natrix maura and the lizard Liolaemus cyanogaster, were investigated. Particular attention was paid to the secretory droplets present in these neurons. Antisera against bovine neurophysins I+II, arginine-vasotocin, and mesotocin were used. The following lectins were applied: concanavalin A (Con A), wheat-germ agglutinin (WGA), and Limax flavus agglutinin (LFA). Adjacent 1-μm-thick methacrylate sections were used to investigate the same secretory neuron and the same colloid droplets with all three antisera and all three lectins. Several sections were treated with trypsin and urea before immunostaining or lectin binding. Con A bound to both vasotocin- and mesotocin-immunoreactive neurons, WGA exclusively to vasotocin neurons; neither of these neurons reacted with LFA. The colloid droplets were present in vasotocin neurons but absent in the mesotocin neurons. These secretory droplets showed an affinity for Con A but not for WGA, and reacted with antisera against neurophysins and vasotocin. In Natrix maura, the colloid droplets became reactive with Con A and the antisera used only after pretreatment of the sections with trypsin and urea. Within the hypothalamo-neurohypophyseal system, antiserum against vasotocin and WGA revealed the same fiber bundles. It is concluded (i) that in reptiles the vasotocin-neurophysin precursor is glycosylated, (ii) that vasotocin neurons have the exclusive capacity to form colloid droplets, and (iii) that these droplets are an intracisternal (RER) storage form of the vasotocin-neurophysin precursor.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 1432-0878
    Keywords: Corticotropin-releasing factor (CRF) ; Immunocytochemistry ; Arginine vasotocin (AVT) ; Mesotocin (MST) ; Co-localization ; Natrix maura (Serpentes)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The anatomical distribution of neurons and nerve fibers containing corticotropin-releasing factor (CRF) has been studied in the brain of the snake, Natrix maura, by means of immunocytochemistry using an antiserum against rat CRF. To test the possible coexistence of CRF with the neurohypophysial peptides arginine vasotocin (AVT) and mesotocin (MST) adjacent sections were stained with antisera against the two latter peptides. CRF-immunoreactive (CRF-IR) neurons exist in the paraventricular nucleus (PVN). In some neurons of the PVN, coexistence of CRF with MST or of CRF with AVT has been shown. Numerous CRF-IR fibers run along the hypothalamo-hypophysial tract and end in the outer layer of the median eminence. In addition, some fibers reach the neural lobe of the hypophysis. CRF-IR perikarya have also been identified in the following locations: dorsal cortex, nucleus accumbens, amygdala, subfornical organ, lamina terminalis, nucleus of the paraventricular organ, nucleus of the oculomotor nerve, nucleus of the trigeminal nerve, and reticular formation. In addition to all these locations CRF-IR fibers were also observed in the lateral septum, supraoptic nucleus, habenula, lateral forebrain bundle, paraventricular organ, hypothalamic ventromedial nucleus, raphe and interpeduncular nuclei.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    ISSN: 1432-0878
    Keywords: Melanin-concentrating hormone ; Immunocytochemistry ; Development, ontogenetic ; Sparus auratus (Teleostei)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The development of the hypothalamic melanin-concentrating hormone (MCH) system of the teleost Sparus auratus has been studied by immunocytochemistry using an anti-salmon MCH serum. Immunoreactive perikarya and fibers are found in embryos, larvae, and juvenile specimens. In juveniles, most labeled neurons are present in the nucleus lateralis tuberis; some are dispersed in the nucleus recessus lateralis and nucleus periventricularis posterior. From the nucleus lateralis tuberis, MCH neurons project a conspicuous tract of fibers to the ventral hypothalamus; this penetrates the pituitary stalk and reaches the neurohypophysis. Most fibers end close to the cells of the pars intermedia, and some reach the adenohypophysial rostral pars distalis. Immunoreactive fibers can also be seen in extrahypophysial localizations, such as the preoptic region and the nucleus sacci vasculosi. In embryos, MCH-immunoreactive neurons first appear at 36 h post-fertilization in the ventrolateral margin of the developing hypothalamus. In larvae, at 4 days post-hatching, perikarya can be observed in the ventrolateral border of the hypothalamus and in the mid-hypothalamus, near the ventricle. At 26 days post-hatching, MCH perikarya are restricted to the nucleus lateralis tuberis. The neurohypophysis possesses MCH-immunoreactive fibers from the second day post-hatching. The results indicate that MCH plays a role in larval development with respect to skin melanophores and cells that secrete melanocyte-stimulating hormone.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...