ISSN:1059-910X    

DOI:10.1002/jemt.1070290602

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY

摘要:

AbstractThe aim of the present study was to provide a comprehensive morphological analysis of the porcine epididymis in view of the specific functions being performed in different regions of this organ. Blood supply and microvasculature of efferent ductules and epididymal duct were investigated by means of corrosion casts which were analysed macroscopically and by scanning electron microscopy. This revealed blood supply to the testis and epididymis to be closely related. The capillary pattern was typical for the efferent ductules, the caput, corpus, and distal cauda epididymidis, respectively. Corrosion casts were also used to visualize the course of the efferent ductules themselves. Tissue samples from different regions of the efferent ductules and epididymal duct were examined by light microscopy and both scanning and transmission electron microscopy, with special attention being payed to transitional areas. Morphological criteria allowed the distinction of three segments within the efferent ductules and of the initial segment, proximal caput, distal caput, corpus, proximal cauda, and distal cauda regions of the epididymal duct. Components of the endocytic apparatus of efferent ductule principal cells were identified by ferritin uptake. Ultrastructural evidence of absorption in the epididymal duct was particularly prominent in proximal and distal caput. Extensive cisternae of rough endoplasmic reticulum and a well‐developed Golgi apparatus were indicative of active protein synthesis and secretion especially in the distal caput and corpus regions. However, assignment of various organelles in principal cells of the epididymal duct to either absorptive or secretory pathways still remains tentative. © 1994 Wiley‐Liss,

ISSN:1059-910X    

DOI:10.1002/jemt.1070290603

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY

ISSN:1059-910X    

DOI:10.1002/jemt.1070290604

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY

摘要:

AbstractThe epithelial nonciliated cells of the efferent ducts are specialized in internalizing many luminal substances. The nonciliated cells actively endocytose sulfated glycoprotein‐2 (SGP‐2), a major secretory protein of Sertoli cells and a homologue of human apolipoprotein J. This study was undertaken to investigate the internalization of Sertoli‐derived SGP‐2 and synthesis of an endogenous efferent duct form of SGP‐2 by nonciliated cells targeted to their secondary lysosomes on animals whose efferent ducts were ligated and/or received injections of tunicamycin. The regulation of synthesis of the endogenous form of SGP‐2 within nonciliated cells by hormones in general and testosterone in particular was also examined using hypophysectomized and castrated animals with or without subsequent testosterone replacement. Quantitative electron microscope immunocytochemistry was performed on groups of animals fixed with 4% paraformaldehyde and 0.5% glutaraldehyde in phosphate buffer for each experimental condition and their controls. In each case, the labeling density (number of gold particles/μm2) within the endosomal (endosomes) and lysosomal (dense multivesicular bodies and secondary lysosomes) compartments was calculated. The results revealed that ligation of the efferent ducts resulted in a significant decrease in the labeling density of the endosomal and lysosomal compartments. However, a baseline of about 18% of controls was still observed in the lysosomal compartment 24 h after ligation. In this compartment similar values were noted 24 h after tunicamycin treatment in conjaction with or without ligation. These results suggest that an endogenous form of SGP‐2 is synthesized by nonciliated cells and presumably targeted via small vesicles from the Golgi apparatus to the lysosomal compartment, but that the major portion of SGP‐2 within this compartment is derived via endocytosis of testicular SGP‐2. Hypophysectomy and castration also showed significant decreases in the labeling densities of these two compartments, but again a baseline level of labeling was noted in the lysosomal compartment. Subsequent testosterone administration to 7‐day hypophysectomized or castrated animals had no effect on the labeling density of the lysosomal compartment, as values comparable to the effect of hypophysectomy or castration alone were noted. Taken together these results suggest that the nonciliated cells of the efferent ducts synthesize an endogenous form of SGP‐2 that is targeted to the lysosomal compartment and which is not regulated by pituitary factors or testosterone.

ISSN:1059-910X    

DOI:10.1002/jemt.1070290605

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY

摘要:

AbstractThe epididymis participates in the post‐testicular maturation and storage of spermatozoa by secreting proteins into the tubule lumen in a region‐specific fashion. The underlying molecular mechanisms leading to biogenesis of these region‐specific differences, however, are not known, although components of the Golgi complex membrane container must undoubtedly be intimately involved. Two monoclonal antibodies raised against Golgi integral membrane proteins, recognizing either thecis(GIMPc) ortransGolgi (GIMPt) cisternae, were used as molecular probes of these regions to begin the characterization of the Golgi complex of in vivo and in vitro epididymal cells. Immunolocalization of GIMPs was performed on frozen sections and in cultured cells using biotin‐streptavidin‐peroxidase immunocytochmistry. In tissue sections, immunostaining of GIMPt was extremely robust in the supranuclear cytoplasm throughout the epididymis. In contrast, no GIMPc immunostaining was detected in the initial segment or in clear cells of the distal caput, corpus, and cauda. Immunodetection of GIMPc and GIMPt in epididymal cells in vitro revealed a reticular, perinuclear pattern, and NH4Cl treatment preferentially disrupted the GIMPt immunolocalization. These results characterizing the molecular components of the Golgi complex will form the basis of additional studies to gain further insight into mechanisms leading to generation of regional differences in epididymal function. © 1994 Wiley

ISSN:1059-910X    

DOI:10.1002/jemt.1070290606

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY

ISSN:1059-910X    

DOI:10.1002/jemt.1070290607

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY

ISSN:1059-910X    

DOI:10.1002/jemt.1070290601

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY