Library

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
  • 1
    Electronic Resource
    Electronic Resource
    Estrogenic modulation of met-enkephalin-induced prolactin secretion in rats (1991)
    Springer
    Anatomy and embryology 183 (1991), S. 455-459 
    Details
    ISSN: 1432-0568
    Keywords: Prolactin ; Met-enkephalin ; Estradiol ; Immunocytochemistry ; Morphometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In order to elucidate the possible role of estrogens in the sex-dependent modulation of met-enkephalin-induced prolactin secretion, and the cellular response at adenohypophyseal level, analyses of serum prolactin levels together with a morphometric study of prolactin-immunoreactive cells were carried out following intraventricular administration of the opioid to estrogenprimed male rats. Administration of the opioid led to an increase in the serum levels of the hormone and, morphometrically, a significant increase in the cellular, cytoplasmic and nuclear areas was observed. When naloxone was administered previously, the above, mentioned changes did not appear, and the values found were similar to those observed in the animals treated only with estrogens. The results suggest that the met-enkephalin-induced prolactin secretion is modulated by the gonadal steroid environment.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00186434
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Morphometrical variations of prolactin cells in response to prolonged and systemic administration of Met-enkephalin in female rats (1992)
    Springer
    Anatomy and embryology 186 (1992), S. 99-105 
    Details
    ISSN: 1432-0568
    Keywords: Prolactin cell ; Met-enkephalin ; Immunocytochemistry ; Ultrastructure ; Morphometr ; Rat(Sprague-Dawley)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A stimulatory effect on prolactin secretion had been describe after acute and systemic administration of met-enkephalin, but the effects of this opioid after chronic administration has not been reported, and the response of mammotroph cells is not clear. As a complement to previous studies, a morphometric analysis (light and electron microscopy) was carried out on prolactin cells from female rats treated chronically with met-enkephalin. Clear features of cellular hyperactivity appeared after chronic and systemic administration of the opioid, and these persisted for two weeks. The changes consisted in increases of cellular, cytoplasmic and nuclear areas, volume and surface densities of the Golgi complex and rough endoplasmic reticulum, as well as the numbers of exocytotic figures. These morphological alterations were paralleled by an increase in serum prolactin levels as detected by RIA. It is concluded that the increase in the synthesis and secretory activity of prolactin cells following chronic and systemic administration of met-enkephalin is very similar to those observed after acute and intraventricular administration.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00710406
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    The automating skeletal and muscular mechanisms of the avian wing (Aves) (1994)
    Springer
    Zoomorphology 114 (1994), S. 59-71 
    Details
    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The avian wing possesses the ability to synchronize flexion or extension of the elbow and wrist joints automatically. Skeletal and muscular mechanisms are involved in generating this phenomenon. The “drawing-parallels” action of the radius and ulna coordinates the movements of the forearm with the carpus. Movement of the radius along the length of the forearm isnot dependent on the shape disparity between the dorsal and ventral condyles of the humerus, nor is it generated by the shape of the dorsal condyle itself. Instead, shifting of the radius toward the wrist occurs during humeroulnar flexion when the radius, being pushed by muscles toward the ulna, is deflected off theIncisura radialis toward the wrist. Movement of the radius toward the elbow occurs during the latter stages of humeroulnar extension when, as the dorsal condyle of the humerus and the articular surface of the ulna's dorsal cup roll apart, the radius gets pulled by the humerus and its ligaments away from the wrist. Synchronization of the forearm with the manus is accomplished by twojoint muscles and tendons.M. extensor metacarpi radialis and the propatagial tendons act to extend the manus in unison with the forearm, whileM. extensor metacarpi ulnaris helps these limb segments flex simultaneously.M. flexor carpi ulnaris, in collaboration with the “drawing-parallels” mechanisms, flexes the carpus automatically when the elbow is flexed, thereby circumducting the manus from the plane of the wing toward the body. In a living bird, these skeletal and muscular coordinating mechanisms may function to automate the internal kinematics of the wing during flapping flight. A mechanized wing may also greatly facilitate the initial flight of fledgling birds. The coordinating mechanisms of the wing can be detected in a bird's osteology, thereby providing researchers with a new avenue by which to gauge the flight capabilities of avian fossil taxa.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00574915
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Coexistence of NADPH-diaphorase with vasopressin and oxytocin in the hypothalamic magnocellular neurosecretory nuclei of the rat (1994)
    Springer
    Cell & tissue research 276 (1994), S. 31-34 
    Details
    ISSN: 1432-0878
    Keywords: NADPH-diaphorase ; Vasopressin ; Oxytocin ; Coexistence ; Hypothalamus ; Rat (Wistar)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Coexistence of NADPH-diaphorase with vasopressin and oxytocin was studied in the magnocellular neurosecretory nuclei of the rat hypothalamus by use of sequential histochemical and immunocytochemical techniques in the same sections. Coexistence was found in all the nuclei examined (supraoptic, paraventricular, circular, fornical, and in some isolated neurons located in the hypothalamic area between the paraventricular and supraoptic nuclei). The ratios of neurons expressing both markers (NADPH-diaphorase and vasopressin, NADPH-diaphorase and oxytocin) in each of the nuclei were very similar. Although further studies must be carried out, the partial coexistence found in all nuclei suggests that NADPH-diaphorase is probably not related to general mechanisms involving vasopressin and oxytocin, but rather in specific functions shared by certain hypothalamic neuronal cell populations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00354781
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Coexistence of NADPH-diaphorase with vasopressin and oxytocin in the hypothalamic magnocellular neurosecretory nuclei of the rat (1994)
    Springer
    Cell & tissue research 276 (1994), S. 31-34 
    Details
    ISSN: 1432-0878
    Keywords: Key words: NADPH-diaphorase – Vasopressin – Oxytocin – Coexistence – Hypothalamus – Rat (Wistar)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. Coexistence of NADPH-diaphorase with vasopressin and oxytocin was studied in the magnocellular neurosecretory nuclei of the rat hypothalamus by use of sequential histochemical and immunocytochemical techniques in the same sections. Coexistence was found in all the nuclei examined (supraoptic, paraventricular, circular, fornical, and in some isolated neurons located in the hypothalamic area between the paraventricular and supraoptic nuclei). The ratios of neurons expressing both markers (NADPH-diaphorase and vasopressin, NADPH-diaphorase and oxytocin) in each of the nuclei were very similar. Although further studies must be carried out, the partial coexistence found in all nuclei suggests that NADPH-diaphorase is probably not related to general mechanisms involving vasopressin and oxytocin, but rather in specific functions shared by certain hypothalamic neuronal cell populations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00354781
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Morphological and functional study of the GH-immunoreactive adenohypophyseal cells in ovariectomized rats (1990)
    Springer
    Journal of molecular histology 22 (1990), S. 683-687 
    Details
    ISSN: 1573-6865
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In view of the existence of a different secretion pattern of growth hormone (GH) between male and female rats, the aim of the present study was to analyse the role played by ovarian steroid hormones in the modulation of such secretion. To do so, postpuberal female rats were ovariectomized and killed at 30 days after the operation. The basal serum levels of growth hormone, together with cell area, cytoplasmic area and nuclear area of the hypophyseal somatotropic cells of normal and ovariectomized rats were compared. The results obtained show that ovariectomy induces a significant decrease (p〈0.05) in the basal serum levels of GH, accompanied by an increase in cellular and cytoplasmic areas, with no significant differences in nuclear area. Overiectomy was also accompanied by an increase in reaction intensity and the number of GH-immunoreactive cells (p〈0.01). These findings point to the shift towards a masculine secretory and morphological pattern following ovariectomy and supports the hypothesis that ovarian steroids intervene in the establishment of a different pattern in females compared to males.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01047453
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Molecular cloning of the gene, expression in E. coli and purification of the thermus aquaticus DNA polymerase I (1992)
    Berlin : Wiley-Blackwell
    Acta Biotechnologica 12 (1992), S. 155-159 
    Details
    ISSN: 0138-4988
    Keywords: Life Sciences ; Life Sciences (general)
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Notes: The Thermus aquaticus DNA Polymerase I gene was isolated by using standard recombinant DNA techniques and cloned into an E. coli vector in front of the lac promoter. E. coli cultures produced thermostable polymerase when induced with the analog IPTG. A purification procedure is shown which renders an enzymatic preparation suitable for PCR reactions.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/abio.370120215
    Library Location Call Number Volume/Issue/Year 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...