ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
Filter
  • Teleost (Gasterosteus)  (2)
  • α-MSH  (2)
  • 1
    Electronic Resource
    Electronic Resource
    The effect of prolactin on kidney structure of the euryhaline teleost Gasterosteus aculeatus during adaptation to fresh water (1976)
    Springer
    Cell & tissue research 166 (1976), S. 319-338 
    Details
    ISSN: 1432-0878
    Keywords: Kidney structure ; Teleost (Gasterosteus) ; Injection of prolactin ; Light and electron microscopy ; Morphometry, stereology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The effect of injections of ovine prolactin on kidney structure was examined in the first 10 days following transfer of seawater sticklebacks to fresh water. In hormone injected animals as well as in controls the glomeruli increase slightly in size after transfer. The podocytes intensify the secretion of mucopolysaccharides, which is indicative of increased turnover of the components of the glomerular basal lamina. The nuclei of the podocytes become enlarged, while those of the juxtaglomerular cells decrease in size. These changes are related to the well known rise of the glomerular filtration rate following transfer to fresh water. Structural indications that prolactin is involved in the control of glomerular filtration were not found. The epithelial cells of the three nephronic segments and of the ureter become considerably better developed after transfer to fresh water. Cell height, nuclear and mitochondrial volume, and surface of the membranes of the basal labyrinth increase in all tubular epithelia, although not to the same extent. Increases are moderate in the first proximal segment, but increasingly higher for the second proximal segment, collecting duct and the ureter. Especially the growth of membrane surface of the basal labyrinth, site of ion transport mechanisms, is impressive. In controls, values characteristic for freshwater fishes are reached in 6 to 9 days for all parameters for cellular development. Prolactin injections greatly stimulate growth rates in all tubular epithelia: freshwater values are reached within 3 days. No further increase was found, however.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00220129
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Morphometrical analysis with the light and electron microscope of the kidney of the anadromous three-spined stickleback Gasterosteus aculeatus, form trachurus, from fresh water and from sea water (1973)
    Springer
    Cell & tissue research 137 (1973), S. 563-588 
    Details
    ISSN: 1432-0878
    Keywords: Juxtaglomerular cells ; Kidney ; Teleost (Gasterosteus) ; Migration ; Kidney structure ; Morphometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The renal corpuscles, juxtaglomerular cells, nephronic tubules, and ureters of female sticklebacks were studied. In fresh water fishes, the diameter of the renal corpuscles is similar to that found in fishes obtained from the sea, whereas the diameter of the glomeruli and the nuclei of the podocytes are slightly larger. Furthermore, in fresh water the podocytes produce secretory globules, which show some of the histochemical characteristics of the substance constituting the glomerular basement membrane. In sea water animals, secretory phenomena are absent. Mesangial cells, which are scarce in fresh water fishes, are numerous in marine animals. Similarly, juxtaglomerular cells, hard to find in fresh water fishes, are prominent in specimens from the sea. The development of the epithelia of the nephronic tubules and of the ureters is better in fresh water. The cells and the nuclei are larger. In the first proximal tubule, which is involved in the reabsorption and the digestion—by lysosomes—of macromolecules, “micropinocytosis vermiformis” occurs. The results of stereological analysis of the fractional volume of the mitochondria and of the relative extent of the infoldings of the basal cell membranes—the location of the ion transport mechanisms—in the three different segments of the nephronic tubule and in the ureter, point to the existence of a structural gradient along the kidney tubules. In fresh water fishes the mitochondrial volume, per surface unit of basal cell membrane, is low in the first proximal segment and is increasingly higher in the other segments, while the highest value is found in the ureter. This structural gradient may be functionally linked with osmotic and ionic gradients, which exist in the renal tubules in fresh water. In the kidney tubules of marine sticklebacks, which do not show a major osmotic gradient, the structural gradient is small. The results are discussed on the basis of the known physiological differences in the function of the kidney of euryhaline teleosts in fresh water and in the sea.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00307231
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Skin ultrastructure in relation to prolactin and MSH function in rainbow trout (Oncorhynchus mykiss) exposed to environmental acidification (1995)
    Springer
    Cell & tissue research 279 (1995), S. 351-358 
    Details
    ISSN: 1432-0878
    Keywords: Skin ; Acidification ; Prolactin ; α-MSH ; Melanocytes ; Oncor hynchus mykiss (Teleostei)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The present study describes the effects of 14 days exposure to acidified (pH 4.0) soft water in the absence of aluminium, on the ultrastructure of the skin in rainbow trout (Oncorhynchus mykiss). Compared to control fish, there was a moderate increase in the incidence of necrosis in the filament cells of the fish exposed to pH 4.0, but since the integrity of the tissue appeared to be maintained, most of the ultrastructural changes observed may be considered to be adaptive. There was an increase in epidermal thickness, a higher frequency of electrondense vesicles in filament cells, an increase in the undulation of the basal lamina, and the penetration of the epidermis by cytoplasmatic processes of melanocytes in acid-exposed specimens. An infiltration of leucocytes into the epidermis, and the appearance of serous mucous cells, was also evident. Whether these events were under the control of prolactin and/or α-MSH, was also investigated, but no indication for activation or inhibition of either prolactin or α-MSH producing cells was obtained. Since a previous study (Balm and Pottinger 1993) had demonstrated that plasma cortisol levels were also identical in control and low pH treated trout throughout a 14 day experimental period, it is concluded that under conditions of environmental acidification, the integument autonomically maintains the adjustments necessary for successful acclimation, presumably via paracrine regulatory circuits.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00318491
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Neuroimmunological regulation of α-MSH release in tilapia (Oreochromis mossambicus) (1993)
    Springer
    Fish physiology and biochemistry 11 (1993), S. 125-130 
    Details
    ISSN: 1573-5168
    Keywords: neuroimmunology ; α-MSH ; teleosts ; LPS ; IL-1 ; pituitary ; Oreochromis mossambicus (tilapia)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Cette étude décrit les effets de l'IL-1 (interleukin 1) et du LPS (bacterial endotoxin lipopolysaccharide) sur la libération de α-MSH (alpha melanocyte stimulating hormone) par le lobe neurointermédiaire (NIL) d'un téléosteen Oreochromis mossambicus (tilapia). Le traitement in vivo du tilapia avec l'IL-1 pendent 8 jours conduit à une inhibition de 49% de la libération basale d'α-MSH mesurée à l'aide d'une technique in vitro de micro-superfusion. Ce traitement ne modifie pas la sensibilité du tissue au TRH. In vitro, la libération de α-MSH est inhibée par le LPS de manière dose-dépendante. En plus de ses effets sur la libération basale de α-MSH, le LPS bloque aussi la réponse à une stimulation par le TRH. Confrontés à des donnés récemment publiés montrant les effets de (neuro-)peptides sur les paramêtres immunitaires et la présence de cytokines chez les poissons, nos résultats établissent le caractère bidirectionnel de la communication entre le système immunitaire et les systèmes (neuro-)endocriniens.
    Notes: Abstract This study describes the effects of IL-1 (interleukin 1) and LPS (bacterial endotoxin lipopolysaccharide) on the release of α-MSH (alpha melanocyte stimulating hormone) from the neurointermediate lobe (NIL) of the teleost Oreochromis mossambicus (tilapia). In vivo treatment of tilapia with IL-1 for 8 days led to a 49% inhibition of basal α-MSH release, measured by means of an in vitro micro-superfusion technique. The treatment did not affect the sensitivity of the tissue to TRH. In vitro, the release of α-MSH was inhibited by LPS in a dose dependent manner. In addition to its effects on the unstimulated release of the hormone, LPS also blunted the response to a TRH stimulation. Together with recent results obtained by others demonstrating the effects of (neuro-)peptides on immune parameters and the presence of cytokines in fish, the present data establish the bidirectional character of the communication between the immune and the (neuro-)endocrine systems in teleosts.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00004558
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...