scholarly journals Effects of PNU157706, a dual 5alpha-reductase inhibitor, on gene expression in the rat epididymis

2004 ◽  
Vol 181 (2) ◽  
pp. 245-261 ◽  
Author(s):  
NA Henderson ◽  
GM Cooke ◽  
B Robaire
Keyword(s):  
Gene Expression ◽  
Initial Segment ◽  
Reductase Inhibitor ◽  
Fluid Transport ◽  
Reductase Activity ◽  
Sperm Maturation ◽  
Metabolism Regulation ◽  
Rat Epididymis ◽  
Cauda Epididymidis

The epididymis is the site of sperm maturation and storage. 5alpha-Reductases (types 1 and 2) are key enzymes in this tissue because they convert testosterone to dihydrotestosterone (DHT), the main androgen regulating epididymal functions. Examining the consequences of inhibiting DHT formation is likely to provide important information regarding the regulation of epididymal functions, yet few inhibitor studies have focused on this tissue. To understand better DHT-mediated regulation of epididymal gene expression, we employed a dual 5alpha-reductase inhibitor and cDNA microarrays to examine the effects of 5alpha-reductase inhibition on gene expression in the initial segment, caput, corpus, and cauda epididymidis. Inhibition of epididymal 5alpha-reductase activity by PNU157706 was confirmed by in vitro enzyme assays. Rats were treated with 0, 0.1, 1.0 or 10 mg/kg per day PNU157706 for 28 days. The weights of DHT-dependent tissues, including the epididymis, were decreased following treatment. The effect of treatment on gene expression was dose-dependent and highly segment-specific. The initial segment responded uniquely in that a similar number of genes increased and decreased in expression compared with the other segments where the majority of affected genes decreased in expression. Some of the more dramatically affected genes were involved in signal transduction as well as fatty acid and lipid metabolism, regulation of ion and fluid transport, luminal acidification, oxidative defense and protein processing and degradation. These are essential processes contributing to the formation of an optimal luminal microenvironment required for proper sperm maturation. These results provide a novel insight into the DHT-dependent mechanisms that control epididymal functions.

Na+/H+-exchange activity and immunolocalization of NHE3 in rat epididymis

2001 ◽  
Vol 280 (3) ◽  
pp. F426-F436 ◽  
Author(s):  
Corinne Bagnis ◽  
Mireille Marsolais ◽  
Daniel Biemesderfer ◽  
Raynald Laprade ◽  
Sylvie Breton
Keyword(s):  
Initial Segment ◽  
Vas Deferens ◽  
Initial Rate ◽  
Proton Secretion ◽  
Efferent Ducts ◽  
Acid Load ◽  
Rat Epididymis ◽  
Cauda Epididymidis ◽  
Exchange Activity

An acidic luminal pH in the epididymis and vas deferens (VD) helps maintain mature sperm in an immotile state during storage. We have previously shown that the majority of proton secretion in the VD is due to the activity of the vacuolar H+-ATPase. Acidification is dependent on luminal sodium in more proximal regions of the epididymis, and we examined the distribution of the Na+/H+ exchanger, NHE3, by immunofluorescence and measured Na+/H+ exchange (NHE) activity in isolated epididymal tubules. NHE3 was detected in the apical pole of nonciliated cells of the efferent ducts and principal cells (PC) of the epididymis. No staining was seen in the distal cauda epididymidis and the VD. Isolated tubules from the distal initial segment (DIS) and proximal cauda epididymidis were perfused in vitro and loaded with the pH-sensitive dye 2′,7′-bis(carboxyethyl)-5(6′)-carboxyfluorescein. Ethylisopropyl amiloride (EIPA) (50 μM) reduced the initial rate of intracellular pH recovery (dpHi/d t), in response to an acute acid load, by 51% and 45% in the DIS and cauda epididymidis, respectively. In the DIS, removal of luminal sodium reduced dpHi/d t by 52%. HOE694 (50 μM) inhibited all EIPA-sensitive dpHi/d t in the DIS, despite the previously reported absence of NHE2 in this region (Cheng Chew SB, Leung GPH, Leung PY, Tse CM, and Wong PYD, Biol Reprod 62: 755–758, 2000). These data indicate that HOE694- and EIPA-sensitive Na+/H+ exchange may participate, together with the H+-ATPase, in luminal acidification in the male excurrent duct.

scholarly journals Castration causes an increase in lysosomal size and upregulation of cathepsin D expression in principal cells along with increased secretion of procathepsin D and prosaposin oligomers in adult rat epididymis

PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0250454
Author(s):  
Lorena Carvelli ◽  
Andrea Carolina Aguilera ◽  
Leila Zyla ◽  
Laura Lucía Pereyra ◽  
Carlos R. Morales ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Complex Formation ◽  
Cathepsin D ◽  
Initial Segment ◽  
Lysosomal Enzymes ◽  
Sperm Maturation ◽  
Principal Cells ◽  
Adult Rat ◽  
Rat Epididymis ◽  
Lysosomal Proteins

In the epididymis, lysosomal proteins of the epithelial cells are normally targeted from the Golgi apparatus to lysosomes for degradation, although their secretion into the epididymal lumen has been documented and associated with sperm maturation. In this study, cathepsin D (CatD) and prosaposin (PSAP) were examined in adult epididymis of control, and 2-day castrated rats without (Ct) and with testosterone replacement (Ct+T) to evaluate their expression and regulation within epididymal epithelial cells. By light microscope-immunocytochemistry, a quantitative increase in size of lysosomes in principal cells of Ct animals was noted from the distal initial segment to the proximal cauda. Androgen replacement did not restore the size of lysosomes to control levels. Western blot analysis revealed a significant increase in CatD expression in the epididymis of Ct animals, which suggested an upregulation of its expression in principal cells; androgens restored levels of CatD to that of controls. In contrast, PSAP expression in Ct animals was not altered from controls. Additionally, an increase in procathepsin D levels was noted from samples of the epididymal fluid of Ct compared to control animals, accompanied by an increased complex formation with PSAP. Moreover, an increased oligomerization of prosaposin was observed in the epididymal lumen of Ct rats, with changes reverted to controls in Ct+T animals. Taken together these data suggest castration causes an increased uptake of substrates that are acted upon by CatD in lysosomes of principal cells and in the lumen by procathepsin D. These substrates may be derived from apoptotic cells noted in the lumen of proximal regions and possibly by degenerating sperm in distal regions of the epididymis of Ct animals. Exploring the mechanisms by which lysosomal enzymes are synthesized and secreted by the epididymis may help resolve some of the issues originating from epididymal dysfunctions with relevance to sperm maturation.

AGE-RELATED CHANGES IN THE METABOLISM OF [3H]TESTOSTERONE IN VITRO BY THE EPIDIDYMIS OF THE IMMATURE RAT

1981 ◽  
Vol 91 (1) ◽  
pp. 43-51 ◽  
Author(s):  
R. G. FOLDESY ◽  
J. H. LEATHEM
Keyword(s):  
Adult Rats ◽  
Testosterone Metabolism ◽  
Pubertal Maturation ◽  
Immature Rat ◽  
Age Related ◽  
Rat Epididymis ◽  
Old Rats ◽  
Prepubertal Rats ◽  
Cauda Epididymidis

We examined the production in vitro of 5α-reduced metabolites from testosterone by the rat epididymis during pubertal maturation. Minced caput and cauda epididymides from 30-, 45-, and 55-day-old rats were incubated with [3H]testosterone for 2 h. Analysis of the radioactive metabolites revealed both similarities and differences in the metabolic patterns compared to those reported for adult rats. As in adults, 5α-dihydrotestosterone was the most abundant metabolite produced by both epididymal segments at all three ages, and it was formed in larger quantities in the caput epididymidis than in the cauda. However, [3H]testosterone metabolism by the epididymis of the immature rat was characterized by a lower formation of 5α-androstane-3α,17β-diol and higher production of 5α-androstane-3,17-dione than in adults. Production of these two metabolites by the caput region increased and decreased respectively, toward adult levels, with increasing age. In addition, the amount of [3H]testosterone metabolized was higher with tissues from prepubertal rats (30 days of age) than with those from rats 55 days of age. These data suggest that testosterone metabolism in the caput begins to change to that of the adult during the period of pubertal maturation but apparently not until later in the cauda epididymidis.

scholarly journals Orchidectomy Induces a Wave of Apoptotic Cell Death in the Epididymis*

Endocrinology ◽  
1998 ◽  
Vol 139 (4) ◽  
pp. 2128-2136 ◽  
Author(s):  
Xueping Fan ◽  
Bernard Robaire
Keyword(s):  
Cell Death ◽  
Initial Segment ◽  
Apoptotic Cell ◽  
Apoptotic Cell Death ◽  
Apoptotic Cells ◽  
Sprague Dawley ◽  
Duct Ligation ◽  
Rat Epididymis ◽  
Cauda Epididymidis ◽  
Caput Epididymidis

Abstract The epididymis is the site where spermatozoa are matured and stored. After orchidectomy, this tissue loses up to 80% of its weight. In the prostate, androgen withdrawal by orchidectomy is associated with apoptotic cell death. The objective of the present study was to investigate whether apoptotic cell death is involved in the androgen-dependent weight loss found in the rat epididymis after orchidectomy. Adult male Sprague-Dawley rats were orchidectomized, and apoptotic cells were identified by in situ TUNEL (TdT-mediated dUTP-digoxigenin nick end-labeling) apoptosis detection. Apoptosis first appeared in the epithelium of the initial segment of the epididymis 18 h after orchidectomy, reached a maximum on day 2, and disappeared by day 5 postorchidectomy. In the caput epididymidis, apoptosis was first found after 24 h, reached a maximum by day 3, and was detectable until day 5. In the corpus epididymidis, apoptosis was first seen on day 4, peaked on day 5, and was undetectable by day 6 postorchidectomy. In the cauda epididymidis, apoptosis was first seen on day 5, peaked on day 6, and was occasionally detected on day 7. Throughout the rat epididymis, apoptotic cell death was localized specifically to principal cells. The presence of apoptosis was confirmed with the observation of a ladder of nucleosomal sized DNA fragmentation by using agarose gel electrophoresis. Androgen replacement therapy after orchidectomy demonstrated that apoptosis in the caput, corpus, and cauda epididymidis was androgen dependent. However, androgens alone could not completely prevent apoptosis in the initial segment of the epididymis. Efferent duct ligation induced a similar pattern of apoptosis in the initial segment of the epididymis as that seen after orchidectomy, but there were fewer apoptotic cells in the caput epididymidis, and no apoptotic cell death in the corpus and cauda epididymidis. We conclude that withdrawal of androgen by orchidectomy induces a wave of apoptotic cell death in the epididymis; we hypothesize that apoptosis in the initial segment is caused primarily by withdrawal of androgen as well as by luminal components coming from the testis.

Effect of angiotensins on electrogenic anion transport in monolayer cultures of rat epididymis

1990 ◽  
Vol 125 (3) ◽  
pp. 449-456 ◽  
Author(s):  
P. Y. D. Wong ◽  
W. O. Fu ◽  
S. J. Huang ◽  
W. K. Law
Keyword(s):  
Fluid Transport ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Chloride Secretion ◽  
Angiotensin Receptors ◽  
Apical Surface ◽  
Monolayer Cultures ◽  
Rat Epididymis ◽  
Specific Antagonist ◽  
Cauda Epididymidis

ABSTRACT Confluent monolayers cultured from the rat cauda epididymidis have been shown to respond to angiotensin I (AI) and angiotensin II (AII) when studied under short-circuit conditions and bathed on both sides with Krebs–Henseleit solution. Both the decapeptide AI and the octapeptide AII elicited transient increases in short-circuit current (SCC) when added to the basolateral as well as to the apical surfaces, with the effect of basolateral application greater than that of apical application. The maximal responses produced by AI and AII were similar with median effective concentrations of 20 to 80 nmol/l. The increase in SCC by AII was dependent upon extracellular Cl− and was inhibited by addition of a Cl− channel blocker, diphenylamine 2-carboxylate, to the apical surface. These patterns of activity suggest that the SCC responses to angiotensins result from electrogenic chloride secretion. Pretreating the monolayers with captopril (100 nmol/l), an angiotensin-converting enzyme (ACE) inhibitor, reduced the response to basolateral application of AI, but completely abolished the response to AI added apically. These results suggest that the response to apical addition of AI was due to conversion of AI to AII which interacts with apical angiotensin receptors. This conversion was mediated by ACE which has been detected in epididymal monolayers. Of the endogenous ACE activity, 86% was found to be inhibited by captopril (100 nmol/l). Responses of the epididymal monolayers to angiotensins were mediated by specific angiotensin receptors. [Sar1,Ile8]-AII, a specific antagonist of the AII receptor, completely inhibited the responses to AI and All but had no effect on the responses to bradykinin and endothelin. The effects of All were mediated by eicosanoid formation since piroxicam, a cyclooxygenase inhibitor, inhibited the AII-induced increase in SCC. This is the first study to demonstrate an effect of angiotensin on epididymal functions. We propose that angiotensin formed locally in the epididymis may play a role in the regulation of electrolyte and fluid transport. Journal of Endocrinology (1990) 125, 449–456

Changes in rat lens proteins and glutathione reductase activity with advancing age

2004 ◽  
Vol 74 (5) ◽  
pp. 329-333 ◽  
Author(s):  
Katakura ◽  
Kishida ◽  
Hirano
Keyword(s):  
Gene Expression ◽  
Glutathione Reductase ◽  
Total Protein ◽  
Flavin Adenine Dinucleotide ◽  
Reductase Activity ◽  
Water Soluble ◽  
Reductase Gene ◽  
Glutathione Reductase Activity ◽  
Old Rats

We examined the changes in the amounts of water-soluble and water-insoluble proteins of rat lenses, and in glutathione reductase activity and glutathione reductase gene expression, with advancing age. The lens total protein increased in 1-month-old rats, 3-month-old rats, and 6-month-old rats, but thereafter decreased in 12-month-old-rats. The water-soluble proteins decreased with advancing age, while the water-insoluble proteins increased. The glutathione reductase activity decreased with advancing age, but the decreased glutathione reductase activity almost recovered by addition of flavin adenine dinucleotide (FAD) in vitro. However, advancing age had no effect on the level of mRNA for glutathione reductase.

Androgen and oestrogen modulation by D-aspartate in rat epididymis

2016 ◽  
Vol 28 (12) ◽  
pp. 1865 ◽  
Author(s):  
S. Falvo ◽  
M. M. Di Fiore ◽  
L. Burrone ◽  
G. Chieffi Baccari ◽  
S. Longobardi ◽  
...  
Keyword(s):  
Gene Expression ◽  
Leydig Cells ◽  
Initial Segment ◽  
Oestrogen Receptors ◽  
Region I ◽  
Early Increase ◽  
Rat Epididymis ◽  
Region Ii ◽  
Aro Genes

Testosterone (T) synthesised in Leydig cells enters the epididymis and may there be converted into dihydrotestosterone (DHT) by 5α-reductase (5α-red) or into 17β-oestradiol (E2) by P450 aromatase (P450-aro). D-aspartate (D-Asp) is known to induce T synthesis in the testis. In this study, we investigated the effects of in vivo D-Asp administration in two major regions of the rat epididymis (Region I: initial segment, caput, corpus; Region II: cauda). The results suggest that exogenous D-Asp was taken up by both regions of rat epididymis. D-Asp administration induced a rapid increase in T, followed by a more gradual decrease in the T : DHT ratio in Region I. In Region II, T levels rapidly decreased and the T : DHT ratio was consistently lower relative to the control. Expression of 5α-red and androgen receptor genes showed a good correlation with DHT levels in both regions. D-Asp treatment also induced an increase of both E2 levels and oestradiol receptor-α (ERα) expression in Region I, whereas neither E2 levels nor ERα expression were affected in Region II. The early increase of P450-aro expression in Region I and late increase in Region II suggests a direct involvement of D-Asp modulation in P450-aro gene expression. Our results suggest that D-Asp modulates androgen and oestrogen levels and expression of androgen and oestrogen receptors in the rat epididymis by acting on the expression of 5α-red and P450-aro genes.

scholarly journals Hormonal regulation of protein synthesis in the rat epididymis. Characterization of androgen-dependent and testicular fluid-dependent proteins

1980 ◽  
Vol 188 (3) ◽  
pp. 667-676 ◽  
Author(s):  
R Jones ◽  
C R Brown ◽  
K I Von Glós ◽  
M G Parker
Keyword(s):  
Protein Synthesis ◽  
Hormonal Regulation ◽  
Initial Segment ◽  
Sodium Dodecyl ◽  
Purification And Characterization ◽  
Testosterone Treatment ◽  
Rat Epididymis ◽  
And Storage

1. Protein synthesis has been investigated in different regions of the rat epididymis by measuring incorporation of [35S]methionine in tissue minces incubated in vitro followed by analysis of labelled proteins on polyacrylamide gels containing sodium dodecyl sulphate. Rates of synthesis were highest in the proximal cauda > distal cauda > initial segment > ductuli efferentes > corpus > distal caput > proximal caput. One protein (mol.wt. 23 000) characterized the initial segment, three proteins (mol.wts. 18 500, 19 000 and 32 000) the caput and one protein (mol.wt. 47 000) the cauda. 2. After castration, [35S]methionine incorporation in all regions of the epididymis was reduced to < 10% of that in normal animals but could be restored to control levels within 5 days by testosterone treatment. Other steroids (corticosterone, oestrogen or progesterone) were ineffective. 3. The synthesis of the 18 500, 19 000, and 32 000 mol.wt. proteins in the caput and the 47 000 mol.wt. protein in the cauda were preferentially regulated by androgens, whilst the synthesis of 23 000 and approx. 80 000 mol.wt. proteins in the initial segment was dependent upon factors present in testicular fluid. 4. The androgen-dependent and testicular fluid-dependent proteins were major components of epididymal secretion. Purification and characterization of the 18 500, 19 000, 23 000 and 32 000 mol.wt. proteins showed them to be acidic glycoproteins with a carbohydrate content of 7.6-13.2%. The 47 000 mol.wt. protein, on the other hand, is highly basic. 5. A possible role for these proteins in the acquisition of motility, fertilizing capacity and storage of spermatozoa in the epididymis is discussed.

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