Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
Filter
  • Cell & Developmental Biology  (2)
  • Micropuncture  (1)
  • 1
    ISSN: 1059-910X
    Keywords: Transport ; Proteins ; Ions ; Micropuncture ; Tight junctions ; Permeability ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: To understand the process of sperm maturation, an understanding of interactions between the spermatozoa with the luminal fluid microenvironment and with the epididymal epithelium is necessary. The composition of epididymal luminal fluid of several species is well documented but the manner by which the epididymis contributes to the formation of this specialized milieu is not so well understood. A major role played by the epididymis is to finely regulate the movement of molecules into and out of the lumen. This ensures that as spermatozoa progress along the duct they are exposed to a continually changing, but optimal environment necessary for their maturation and survival. This review focusses on our current understanding of the contributions of the epididymal epithelium to the formation of a specialized luminal fluid microenvironment. The role of the blood-epididymis barrier, the composition of the epididymal luminal fluid, the permeability properties of the epididymal epithelium, and recent studies on a number of luminal fluid proteins and expression of the genes which encode these proteins are discussed. © 1995 Wiley-Liss, Inc.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1040-452X
    Keywords: Northern analysis ; Microperfusion ; Glutathione ; pH ; Transport ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Following Northern analysis, GGT mRNA was found predominantly within the caput epididymides and kidney. The size of mRNAs for kidney, caput, corpus, and ducts deferens were 2.2, 2.3, 2.2., and 2.3 kb, respectively, whereas cauda showed a doublet of 2.2 and 2.3 kb. GGT transpeptidation and hydrolytic activity within epididymal luminal fluids collected by micropuncture showed caput=corpus〉cauda and corpus〉caput〉cauda, respectively. Caput luminal GGT transpeptidation activity was significantly inhibited by serine-borate and was optimal at pH 8.0. The calculated Km and Vmax values for hydrolysis of GSH by caput luminal GGT were 0.06 μM and 2.19 nmoles/min/μl luminal fluid at pH 8.5 compared to 0.49 μM and 0.49 nmoles/min/μl luminal fluid, respectively, at the physiological pH 6.5 of caput fluid. These studies would suggest that the epididymis can control the activity of luminal GGT by pH. Lower Km (0.12 μM) and higher Vmax (1.13 nmoles/min/μl luminal fluid) values were also calculated when GSSG was used compared to GSH. Results from Triton X-114 partitioning experiments suggest that luminal GGT probably exists in both membrane bound and nonmembrane bound forms. Western blot analysis of proteins within epididymal luminal fluids revealed both subunits of GGT in all epididymal regions studied. However, two lower molecular bands, approximately 22 kDa and 21 kDa, were also observed in cauda fluid. It is suggested that as GGT is transported along the epididymal duct it undergoes degradation, which accounts for its loss of activity in the distal epididymal regions. Epididymal GGT may not be involved in the transport of L-glutamate since transport was not related to the degree of GGT mRNA expression along the epididymal duct.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...