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  • Epididymal ultrastructure  (2)
  • Directed secretion  (1)
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 253 (1988), S. 631-637 
    ISSN: 1432-0878
    Keywords: Epididymal ultrastructure ; Transcytosis ; Protein transport ; Fluid-phase endocytosis ; Epididymal arterial perfusion ; Rat (Sprague-Dawley) ; Golden hamster ; Mouse (CB6/F1)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The transport of protein across the cells of the epididymal epithelium was studied using horseradish peroxidase. Transient vascular perfusion of the epididymis of the rat and golden hamster was achieved by pulsatile retrograde infusion into the testicular artery. Peroxidase was found in the interstitium and in the epithelium, located in vesicles, vacuoles and multivesicular bodies of principal, clear and apical cells. Similar findings were obtained in mice after systemic injection of the tracer. In the rat, discharge to the lumen was confirmed by the appearance of enzyme activity in luminal fluid from the caput epididymidis after local injection. The extent of transport amounted to no more than what has been considered leakage in physiological experiments, and the time-course of appearance complemented that found by electron microscopy. The level of transcytosis after pulsatile administration of peroxidase in vivo, as judged from the occurrence of tracer in the epithelium, was much less than that obtained during constant immersion in vitro. The protein was present in multivesicular bodies of principal cells and in vesicles of clear cells at short times after presentation in vitro, when it could not have arrived by endocytosis from the lumen. This suggests that routing of basal endocytic vesicles to the lysosomal apparatus occurs.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 248 (1987), S. 527-530 
    ISSN: 1432-0878
    Keywords: Epididymal ultrastructure ; Peroxidase ; Protein transport ; Fluid-phase endocytosis ; Sprague-Dawley rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Experiments were performed to clarify the debate over the entry of circulating proteins into the epididymal lumen by use of the marker horseradish peroxidase (HRP). Epididymal tubules from the caput epididymidis of the rat were immersed in medium TC 199 containing HRP (3.5 mg/ ml) for 5 min to 3 h at 33° C. Sections were examined for the presence of tracer within the epithelial cells by electron microscopy. From 5 min to 3 h, vesicles containing peroxidase reaction products were found throughout the cytoplasm of the principal cells. Vesicles occurred close to both the basal and apical membranes, and many were found opening into the interstitial space and lumen, depending on the length of incubation. By 5 min labelled vesicles were infrequently found in the apical part of the cells. Reaction product was observed in the epididymal lumen adhering to the microvilli from 30 min of incubation onwards. At all periods of incubation peroxidase was present at the base of the epithelium and between the cells, but it was never found within the tight junctional complexes, and no reaction deposits were found within epithelial cells of tubules incubated in the absence of peroxidase. It is concluded that large molecules leaving the capillaries may enter the epididymal lumen in the caput by means of fluid-phase endocytosis.
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 256 (1989), S. 567-572 
    ISSN: 1432-0878
    Keywords: Epididymis ; Monolayer culture ; Directed secretion ; Phosphatases ; Glucosaminidase ; Rat (Sprague-Dawley)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A cell culture system is characterised for monolayers of immature rat epididymal epithelial cells grown on permeable supports. Cover of the filters was achieved by days 4–5 and was maintained for 9–12 days. The secretion of acid phosphatase (ACP), alkaline phosphatase (AKP) and N-acetylglucosaminidase (NAG) into apical and basal compartments of culture chambers was monitored with time in culture for cells from the proximal and distal epididymis of 37-day-old animals. There was independent secretion of the three enzymes: secretion of NAG and AKP was mainly apical, that of ACP basal; daily secretion of ACP and AKP was constant throughout culture, that of NAG declined; there was greater secretion of NAG and AKP by cells from the proximal than the distal region. The initial high apical secretion of NAG is thought to reflect loss of enzyme from unattached cells, whereas the later AKP secretion is truly directional. Secretion was not influenced by the enzymes used in cell preparation. The cytotoxic agent Thimerosal inhibited secretion of all enzymes when placed beneath the cultures, indicating that secretion depended on viable cells, but initially stimulated release of AKP when applied above the cells possibly reflecting release from the cell membrane.
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