OBJECTIVETo establish a prostatic hyperplasia model with Beagle canines.

METHODSTwenty-four two-year-old male Beagle canines were divided into treatment and control groups at random and were administrated testosterone propionate (TP) through intramuscular injection two months after castration. Three treatment groups were given 0.8, 2.5 and 7.5 mg/kg TP respectively, and the control was given the same volume of vehicle. Two months later, half of the animals were killed and the serum and prostate were prepared. After the wet weight and volume of prostate were measured, the dihydrotestosterone (DHT) level of serum and prostate were detected with DHT radioimmunoassay (RIA) kit, and paraffine section from canine prostate was stained by the HE methods. Pictures were taken by digital camera under microscope, and all the pictures were analyzed by computer for epithelial cell height and acinar luminal area of prostate with micro image analysis software. The canine prostate volume was measured with ultrasonic diagnosis instrument before castration, at two months after castration and at two months after being given TP.

RESULTSThe ultrasonic results showed that the prostate volumes of all the canines were smaller at two months after castration than before castration (P < 0.05), and after having been administrated TP for two months, and the prostate volumes of all treatment groups were larger than those of the control group (P < 0.01). The wet weight of the prostate of the treatment group was higher than that of the control group (P < 0.05), and both had dose-dependent relationship. The DHT level of serum and prostate of the canines became higher with the increase of TP dose. The results of micro image analysis showed that the acinar luminal area of prostate was enlarged, and the epithelial cell height increased with larger dose of TP.

CONCLUSIONSIt is practicable to establish prostatic hyperplasia model in Beagle canines after two months of TP administration.

Animals ; Dihydrotestosterone ; blood ; Disease Models, Animal ; Dogs ; Male ; Orchiectomy ; Prostatic Hyperplasia ; etiology ; Testosterone Propionate ; pharmacology

BACKGROUND5α-Reductase inhibitors (5α-RI) act by inhibiting the conversion of testosterone to dihydrotestosterone (DHT), thereby preventing DHT induced benign prostatic hyperplasia. The existing 5α-RIs can be classified into two types: competitive and noncompetitive. Currently, limited evidence is available concerning the effect differences between the two types of 5α-RI on androgens. The purpose of this study was to assess the effects of competitive and noncompetitive 5α-RIs on serum and intra-prostatic androgens in beagle dogs.

METHODSTwenty beagles with spontaneous benign prostatic hyperplasia were randomly allocated into two groups: epristeride group (n = 10) in which beagles were treated with epristeride at 1 mg/kg once a day for 3 months, and finasteride group (n = 10) in which beagles were treated with finasteride at 1 mg/kg once a day for 3 months. The levels of intra-prostatic testosterone and DHT were measured before treatment and on day one after three months medication. Serum levels of testosterone and DHT were measured at the same time points. Changes in androgen levels before and after treatment were analyzed, and comparisons were made within each treatment group and between treatment groups.

RESULTSAfter 3-month treatment, serum and intra-prostatic DHT levels all decreased significantly in both the epristeride and finasteride groups. The change of DHT in serum was significantly higher in the finasteride group (-14% and -43% in epristeride and finasteride groups respectively, with P < 0.001); however there was no significant difference in the changes of intra-prostatic DHT between the two groups (-47% and -51% in epristeride and finasteride groups, respectively, P = 0.304). The decreases in DHT levels were accompanied by reciprocal increases in serum and intra-prostatic testosterone levels. Changes of testosterone were significantly higher in finasteride group both in serum (20% and 42% in epristeride and finasteride groups, respectively, P < 0.001) and in prostate tissue (18% and 29% in epristeride and finasteride groups, respectively, P = 0.004).

CONCLUSIONSTwo types of 5α-RI have similar effects in reducing DHT in prostate tissue in beagles. Competitive 5α-RI may reduce serum DHT to a greater scale, and significantly increase testosterone in beagle serum and prostate.

5-alpha Reductase Inhibitors ; pharmacology ; Androgens ; blood ; metabolism ; Androstadienes ; pharmacology ; Animals ; Dihydrotestosterone ; blood ; metabolism ; Dogs ; Finasteride ; pharmacology ; Male ; Prostate ; drug effects ; metabolism

AIMTo investigate the ultrastructural changes of penile corpus cavernosum and tunica albuginea in rats treated with castration or finasteride.

METHODSEighteen male Sprague-Dawley rats of nine weeks old were randomly divided into three groups with 6 rats each. Group A served as the control, Group B was castrated and Group C, treated with finasteride. Four weeks later, rats were anesthetized and blood samples obtained for the determination of serum testosterone (T) and dihydrotestosterone (DHT) levels; penile tissues were taken for scanning electron microscopy.

RESULTSThe T, free T and DHT levels in Group B and the DHT level in Group C were significantly lower than those in Group A (P<0.05). The tunica albuginea was significantly thinner in Group B than that in Group A (P<0.05), but there was no significant difference between Group C and Group A (P>0.05). Elastic fibers in the tunica albuginea of Group A were very rich and arranged regularly and undulatedly, but in Group B, most of the elastic fibers were replaced by collagenous fibers. In Group C, the tunica albuginea was mainly composed of thick and irregular-arranged collagenous fibers. In Group A, there were abundant smooth muscle fibers in the trabeculae of corpus cavernosum, but they were much less in Group C and scarce or even disappeared in Group B. In Groups B and C, the diminished/disappeared smooth muscle fibers were replaced by irregularly arranged collagenous fibers.

CONCLUSIONIn rats, androgen is essential for maintaining the normal structure of penile tunica albuginea and corpus cavernosum.

Animals ; Dihydrotestosterone ; blood ; Enzyme Inhibitors ; pharmacology ; Finasteride ; pharmacology ; Male ; Microscopy, Electron, Scanning ; Orchiectomy ; Penis ; pathology ; ultrastructure ; Rats ; Rats, Sprague-Dawley ; Testosterone ; blood ; deficiency

AIMTo investigate the relationship between low androgen level and ultrastructure of vascular endothelium.

METHODSForty-eight male Sprague-Dawley rats were randomly divided into four groups: group A, normal rats with sham castration; group B, castrated rats; group C, castrated rats given testosterone (T) undecanoate; and group D, intact rats treated with 5alpha-reductase inhibitor. After 10 weeks of treatment or castration, rats in different groups were killed and serum T, free T (FT) and dihydrotestosterone (DHT) were measured. The aortic endothelia were scanned under electron microcopy and the Vascular Endothelium Structure Score (VESS) was computed.

RESULTSSerum T and FT concentrations of rats in group B were significantly lower than those of the other three groups (P < 0.01); DHT concentrations of group D rats were significantly decreased (P < 0.01) when compared with those of groups A and C. Rats in groups B and D rats (with low androgen levels) had obvious damage to their endothelial surfaces, which appeared crimpled, rough, adhesive and ruptured, and had high destruction of VESS.

CONCLUSIONThese results suggest that low concentrations of T and DHT are associated with ultrastructural damage of the aortic endothelia in male rats.

5-alpha Reductase Inhibitors ; Animals ; Aorta ; drug effects ; ultrastructure ; Dihydrotestosterone ; blood ; Endothelium, Vascular ; drug effects ; ultrastructure ; Enzyme Inhibitors ; pharmacology ; Male ; Orchiectomy ; Rats ; Rats, Sprague-Dawley ; Testosterone ; blood ; pharmacology

AIMTo examine the physiological role of the androgen receptor (AR) in the PC-3 cell line by transfecting full-length functional AR cDNA driven by its natural human AR promoter.

METHODSWe generated an AR-expressing PC-3(AR)9 stable clone that expresses AR under the control of the natural human AR promoter and compared its proliferation to that of the PC-3(AR)2 (stable clone that expresses AR under the control of the cytomegalovirus (CMV) promoter, established by Heisler et al.) after androgen treatment.

RESULTSWe found that dihydrotestosterone (DHT) from 0.001 nmol/L to 10 nmol/L induces cell cycle arrest or inhibits proliferation of PC-3(AR)2 compared with its vector control, PC-3(pIRES). In contrast, PC-3(AR)9 cell growth slightly increased or did not change when treated with physiological concentrations of 1 nmol/L DHT.

CONCLUSIONThese data suggest that intracellular control of AR expression levels through the natural AR promoter might be needed for determining AR function in androgen-independent prostate cancer (AIPC) PC-3 cells. Unlike previous publications that showed DHT mediated suppression of PC-3 growth after transfection of viral promoter-driven AR overexpression, we report here that DHT-mediated PC-3 proliferation is slightly induced or does not change compared with its baseline after reintroducing AR expression driven by its own natural promoter, as shown in PC-3(AR)9 prostate cancer cells.

Cell Cycle ; drug effects ; Cell Line, Tumor ; Cell Proliferation ; DNA, Complementary ; biosynthesis ; Dihydrotestosterone ; pharmacology ; Humans ; Male ; Promoter Regions, Genetic ; Prostatic Neoplasms ; metabolism ; pathology ; Receptors, Androgen ; biosynthesis ; genetics ; Transfection

OBJECTIVETo investigate whether 5alpha-reductase inhibitor and dihydrotestosterone (DHT) play a role in spermatogenesis in male rats.

METHODSThirty-two male rats were divided into 4 groups (Groups C, T, F and FT). Group C received plant oil injection and oral starch perfusion, Group T testosterone undecanoate (TU, 20 mg/kg) injection and oral starch perfusion, Group F plant oil injection and oral Finasteride perfusion, and Group FT TU (20 mg/kg) injection and oral Finasteride perfusion. Data on serum T and DHT, sperm count, sperm mobility and reproductive function were collected and analysed.

RESULTS(1) 5alpha-reductase inhibitor, Finasteride and TU reduced the weight of the testis and epididymis in the experiment groups compared with the negative control (Group C), but TU increased the weight of the prostate while Finasteride decreased it compared with the positive control (Group T). TU combined with Finasteride could counteract the effect of the weight increase of the prostate, but not that of the testis. (2) Finasteride, or Finasteride combined with TU, reduced the DHT but increased the testosterone level in comparison with the control group. (3) Both Finasteride and TU could inhibit epididymal sperm count and reproductive function compared with the control, but the effect was less significant in Group FT than in Group F.

CONCLUSIONHigh dosages of 5alpha-reductase inhibitor, Finasteride, can suppress male reproductive function, but the inhibiting effect could be counteracted by administration of 5alpha-reductase inhibitor along with TU.

Animals ; Cholestenone 5 alpha-Reductase ; antagonists & inhibitors ; Dihydrotestosterone ; pharmacology ; Dose-Response Relationship, Drug ; Finasteride ; pharmacology ; Male ; Organ Size ; Prostate ; drug effects ; pathology ; Rats ; Rats, Sprague-Dawley ; Spermatogenesis ; drug effects ; Testis ; drug effects ; pathology ; Testosterone ; analogs & derivatives ; pharmacology

OBJECTIVETo explore the molecular mechanism of dutasteride inhibiting fertility by studying its effects on the expressions of the epididymal epithelial junction proteins Claudin1 and β-catenin in rats.

METHODSSixteen 3-month-old SD male rats were equally divided into an experimental and a negative control group to be treated intragastrically with dutasteride at 40 mg/kg per day and the same dose of solvent, respectively, for 14 consecutive days. Then, the sperm motility and morphology of the rats were detected by computer-assisted sperm analysis, the serum levels of testosterone (T) and dihydrotestosterone (DHT) measured by ELISA, changes in the tight junction of epididymal cells observed under the transmission electron microscope, the protein and gene expressions of Claudin1 and β-catenin determined by RT-PCR and immunohistochemistry, and the conception rate of the mated female rats calculated.

RESULTSDutasteride significantly suppressed the serum DHT level, sperm motility, and fertility of the rats (P <0.05). Interspaces between epididymal epithelial cell tight junctions were observed, the volume of epididymal fluid obviously increased, and the expressions of Claudin1 and β-catenin gene and protein remarkably downregulated in the experimental rats (P <0.05).

CONCLUSIONDutasteride can significantly inhibit the fertility of male rats by reducing the serum DHT level, suppressing Claudin1 and β-catenin expressions, and damaging epididymal epithelial cell junctions.

Animals ; Azasteroids ; pharmacology ; Claudin-1 ; metabolism ; Dihydrotestosterone ; blood ; Dutasteride ; Epididymis ; drug effects ; metabolism ; Female ; Fertility ; drug effects ; Humans ; Intercellular Junctions ; drug effects ; Male ; Rats ; Rats, Sprague-Dawley ; Sperm Motility ; drug effects ; Testosterone ; blood ; Urological Agents ; pharmacology ; beta Catenin ; metabolism

AIMTo identify proteins induced by androgen in Sertoli cells during spermatogenesis.

METHODSWe analyzed protein profiles in TM4 Sertoli cells treated with dihydrotestosterone (DHT) using surface enhanced laser desorption ionization time-of-flight mass spectrometry (SELDI-TOF-MS).

RESULTSWe found increases in the expression of a 5.0-kDa protein at 15 min, an 11.3-kDa protein at 24 h and 4.3 kDa, 5.7 kDa, 5.8 kDa, 9.95 kDa and 9.98 kDa proteins at 48 h after the treatment. In contrast, the expression of 6.3 kDa and 8.6 kDa proteins decreased at 30 min, and 4.9 kDa, 5.0 kDa, 12.4 kDa and 19.8 kDa proteins at 48 h after the treatment. The 11.3-kDa protein was identified as macrophage migration inhibitory factor (MIF) known to having various functions. The 9.98-kDa protein was identified as calgizzarin related to calcium channels. The timing of their expression suggests that MIF and calgizzarin are involved in late regulation of spermatogenesis in Sertoli cells by androgen.

CONCLUSIONMIF and calgizzarin are two important androgen-responsive proteins produced by Sertoli cells and they might play a role in regulating spermatogenesis.

Androgens ; pharmacology ; Animals ; Cell Line ; Dihydrotestosterone ; pharmacology ; Gene Expression Regulation ; drug effects ; Kinetics ; Macrophage Migration-Inhibitory Factors ; genetics ; Male ; Mice ; Protein Array Analysis ; S100 Proteins ; genetics ; Sertoli Cells ; drug effects ; physiology ; Spermatogenesis

OBJECTIVETo determine the expression of Skp2 in different prostate cancer (PCa) cell lines and tissues, and explore its influence on the androgen receptor (AR) signaling pathway and development of castration-resistant prostate cancer (CRPC).

METHODSThe expression levels of Skp2 and AR in different PCa cell lines were detected by Western blot. After knockdown of Skp2 in the C4-2 and 22RV1 cells transfected with shRNA, the expressions of AR and P27 were determined and the activity of ARR3-Luc measured by dual-luciferase reporter gene assay following treatment with dihydrotestosterone (DHT). The expressions of AR and Skp2 in human naïve PCa or CRPC specimens were detected by immunohistochemical staining followed by analysis of their differences and correlation.

RESULTSThe Skp2 protein expression level was significantly higher in the C4-2 or 22RV1 cells than in the LNCaP cells. DHT treatment increased the expression of Skp2 in the C4-2 cells, but knock-down of Skp2 significantly up-regulated the expression of the well-known downstream protein P27 and down-regulated that of AR. Consistently, DHT treatment increased the activity of ARR3-Luc, while knockdown of Skp2 remarkably decreased it in the C4-2 and 22RV1 cells (P < 0.05). In addition, significantly higher expressions of Skp2 and AR were observed in the CRPC than in the naïve specimens (P < 0.05), with a positive correlation between the two proteins (r = 0.658 1, P < 0.05).

CONCLUSIONSkp2 can enhance the expression and transcription activity of the AR protein in CRPC cells or tissues and is promising to be a critical molecular therapeutic target.

Androgens ; pharmacology ; Cell Line, Tumor ; Dihydrotestosterone ; pharmacology ; Disease Progression ; Gene Knockdown Techniques ; Humans ; Male ; Neoplasm Proteins ; genetics ; metabolism ; Prostatic Neoplasms, Castration-Resistant ; metabolism ; Receptors, Androgen ; genetics ; metabolism ; S-Phase Kinase-Associated Proteins ; physiology ; Transcriptional Activation ; Up-Regulation

OBJECTIVETo investigate the effect of dihydrotestosterone (DHT) on the gene transcriptions and expressions of Smad3 and Smad4 in androgen dependent prostate cancer cell line LNCaP, and whether this effect can be suppressed by the androgen receptor inhibitor flutamide.

METHODSThe androgen dependent prostate cancer cell line LNCaP was cultured in RPMI 1640 medium and treated with different concentrations of DHT(2, 10, 50 nmol/L) and flutamide (100 nmol/L). Quantitative reverse transcription PCR (RT-PCR) was used to detect the mRNAs of Smad3 and Smad4. The expressions of Smad3 and Smad4 protein were detected by Western blot assay.

RESULTSCompared with the control group without any DHT or flutamide, higher concentration(10, 50 nmol/L) of DHT enhanced the transcription of Smad3 mRNA (P <0.05). Serial concentrations of DHT increased the expression of Smad3 protein(P < 0.05). Flutamide inhibited the up-regulation of both Smad3 mRNA transcription and expression significantly (P <0.05). 10 nmol/L DHT significantly suppressed the transcription of Smad4 (P <0.05). There was considerable suppressions of Smad4 expression at the presence of DHT in different concentrations (P < 0.05). And the degree of this suppression was more significant than that of DHT on Smad4 mRNA transcription. Flutamide inhibited the suppressive effects of DHT on both Smad4 mRNA transcription and expression.

CONCLUSIONDHT can enhance the transcription and expression of Smad3, while it decreases the transcription and expression of Smad4 in LNCaP cell line. There is a possible crosstalk between the AR signal and TGF-beta signal passways at the level of Smads.

Androgens ; physiology ; Cell Line, Tumor ; Dihydrotestosterone ; pharmacology ; Flutamide ; pharmacology ; Humans ; Male ; Neoplasms, Hormone-Dependent ; metabolism ; Prostatic Neoplasms ; metabolism ; RNA, Messenger ; genetics ; Reverse Transcriptase Polymerase Chain Reaction ; Signal Transduction ; drug effects ; Smad3 Protein ; biosynthesis ; genetics ; Smad4 Protein ; biosynthesis ; genetics ; Transcription, Genetic