An age-dependent cellular change of DNA contents in the testis of Sprague-Dawley rats was investigated by flow-cytometric method. Testicular cell suspensions at the age of 4, 5, 6, 7, 8, 10, 12, 16 and 26 weeks were prepared and stained with propidium iodide. The relative proportions in the number of mature and immature haploid (1n), diploid (2n), S-phase and tetraploid (4n) cells were calculated. The proportion in the number of mature haploid cells was sharply increased to the age of 10 weeks (about 38%), thereafter increased slightly to the level of 42% at the age of 26 weeks. The proportion of immature haploid cells was dramatically increased to the age of 6 weeks, then maintained at the level of 20 to 30% thereafter. The proportion of diploid cells was 64% at the age of 4 weeks, then decreased gradually through the age of 26 weeks. The proportion of S-phase cells was increased to the age of 4 weeks, then maintained at a plateau level to the age of 26 weeks. The proportion of tetraploid cells were about 26% at the age of 4 weeks, then decreased gradually to the age of 26 weeks. These results suggest that the proportions of testicular cells may depend on the age of the rat and that the flow cytometric method may be useful in the evaluation of the spermatogenic status with regard to accuracy and sensitivity.
Animals ; DNA/*analysis/genetics ; Diploidy ; Flow Cytometry/methods/veterinary ; Haploidy ; Male ; Rats ; Spermatogenesis ; Testis/chemistry/*growth & development

OBJECTIVETo investigate the dose-dependent toxic effect of soybean isoflavone extracts (SIE) on reproductive development in immature rats.

METHODSGrowing male and female rats (n = 50 each, 4 weeks) were divided into five groups fed with a standard cereal-based diet and gastrogavaged daily with 0, 30, 150, 300, and 600 mg SIE/kg body weight, respectively, for 12 weeks. Body weight, organ weights, and serum level of estrogen and testosterone were measured.

RESULTSOral administration of SIE had no effect on food intake but decreased food efficiency ratio (P < 0.01). Suppression on body weight gain by SIE was dose-dependent and the effect was greater on male than on female rats (P < 0.01). SIE at high doses exhibited hepatotoxicity by increasing a relative liver weight, and also caused a smaller uterus but a greater relative ovary in female rats, while leading to larger relative testis and epididymis in male rats. SIE could decrease progesterone concentrations in female rats, whereas in male rats it reduced not only total testosterone level but also sperm count compared with the control group (P < 0.05).

CONCLUSIONSIE at a range of 50-1000 times of human intake level affects not only growth but also development of reproductive system in growing rats.

Animals ; Body Weight ; drug effects ; Epididymis ; drug effects ; growth & development ; Estradiol ; blood ; Female ; Isoflavones ; toxicity ; Liver ; drug effects ; growth & development ; Male ; Organ Size ; drug effects ; Ovary ; drug effects ; growth & development ; Progesterone ; blood ; Rats ; Rats, Sprague-Dawley ; Soybeans ; chemistry ; Sperm Count ; Testis ; drug effects ; growth & development ; Testosterone ; blood ; Uterus ; drug effects ; growth & development

AIMTo study the expression and regulation of Smad1, Smad2 and Smad4 proteins (intracellular signaling molecules of transforming growth factor-b family) in rat testis during postnatal development.

METHODSThe whole testes were collected from SD rats aged 3, 7, 14, 28 and 90 (adult) days. The cellular localization and developmental changes were examined by immunohistochemistry ABC method with the glucose oxidase-DAB-nickel enhancement technique. Quantitative analysis of the immunostaining was made by the image analysis system. The Smads proteins coexistence in the adult rat testis was tested by the double immune staining for CD14-Smad4 and Smad2-Smad4. The protein expression of Smad during rat testicular development was examined by means of Western blots.

RESULTSSmad1, Smad2 and Smad4 were present throughout testicular development. The immunostaining of Smad1 and Smad2 were present in spermatogenic cells. A positive immunoreactivity was located at the cytoplasm, but the nucleus was negative. Smad1 was immunolocalized at the d14, d28 and adult testes, while Smad2, at the d7, d14, d28 and adult testis. There was positive immunoreaction in the Sertoli cells and Leydig cells as well. The immunolocalization of Smad4 was exclusively at the cytoplasm of Leydig cells and the nuclei were negative throughout the testicular development. No expression was detected in the germ cells. The results of image and statistical analysis showed that generally the expression of Smad1, Smad2 and Smad4 in the testis tended to increase gradually with the growth of the rat.

CONCLUSIONThe present data provide direct evidences for the molecular mechanism of TGF-bgr action in rat testes during postnatal development and spermatogenesis.

Animals ; Blotting, Western ; DNA-Binding Proteins ; analysis ; biosynthesis ; Immunohistochemistry ; Male ; Rats ; Rats, Sprague-Dawley ; Signal Transduction ; physiology ; Smad Proteins ; Smad1 Protein ; Smad2 Protein ; Smad4 Protein ; Testis ; chemistry ; growth & development ; physiology ; Trans-Activators ; analysis ; biosynthesis

AIMTo investigate the role of a novel dipeptidyl peptidase 8 transcript variant (DPP8-v3) gene in testis development and/or spermatogenesis.

METHODSA human testis cDNA microarray was hybridized with mRNA of human adult and fetal testes. Differentially expressed clones were sequenced and characterized and their expression was analyzed by real-time reverse transcription polymerase chain reaction (RT-PCR) and Southern-blot analysis.

RESULTSA new transcript variant of the human dipeptidyl peptidase (DPP8), exhibiting a 5-fold higher expression level in human adult than that in fetal testes, was cloned and was named DPP8 variant 3 (DPP8-v3). The full-length sequence of DPP8-v3 was 3,030 bp, encoding a protein of 898 amino acids.

CONCLUSIONDPP8-v3 is a novel human DPP8 transcript variant highly expressed in the adult testis. Similar to DPPIV, DPP8-v3 may play a key role in the immunoregulation of testes and accordingly may influence spermatogenesis and male fertility.

Adult ; Amino Acid Sequence ; Base Sequence ; Blotting, Southern ; DNA Primers ; DNA, Complementary ; Dipeptidases ; chemistry ; genetics ; Gene Expression Profiling ; Humans ; Male ; Molecular Sequence Data ; Nucleic Acid Hybridization ; RNA, Messenger ; genetics ; Reverse Transcriptase Polymerase Chain Reaction ; Sequence Homology, Amino Acid ; Testis ; embryology ; enzymology ; growth & development

AIMTo identify and characterize a novel gene with potential roles in testis development and spermatogenesis.

METHODSA cDNA microarray was constructed from a human testis large insert cDNA library and hybridized with probes of human or mouse adult and fetal testes. Differentially expressed genes were isolated and sequenced. RT-PCR was used to test the tissue distribution of the genes of interest and in situ hybridization was performed to localize the gene expression in the mouse testis. A range of bioinformatical programs including Gene Runner, SMART, NCBI Blast and Emboss CpGPlot were used to characterize the new gene's feature.

RESULTSA novel testis-specific gene, NYD-SP5, was differentially expressed in fetal and adult testes. The deduced protein structure of NYD-SP5 was found to contain an IQ motif (a short calmodulin-binding motif containing conserved Ile and Gln residues), a Carbamate kinase-like domain, a Zn-dependent exopeptidase domain and a lactate dehydrogenase (LDH) C-terminal-like domain. RT-PCR analysis revealed that NYD-SP5 was predominantly expressed in the testis but not in other 15 tissues examined. In situ hybridization and RT-PCR examinations revealed that the expression of NYD-SP5 was confined in the male germ cell but not present in the somatic cell in the testes.

CONCLUSIONNYD-SP5 is a newly found testis-specific gene with potential roles in testis development and spermatogenesis through a calmodulin-activated enzyme.

Amino Acid Sequence ; Animals ; Base Sequence ; DNA, Complementary ; In Situ Hybridization ; Male ; Mice ; Molecular Sequence Data ; Oligonucleotide Array Sequence Analysis ; Proteins ; chemistry ; genetics ; physiology ; RNA, Messenger ; genetics ; Reverse Transcriptase Polymerase Chain Reaction ; Sequence Homology, Amino Acid ; Spermatogenesis ; genetics ; Testis ; growth & development ; metabolism

The arrenotokous toxicity of triptolide was evaluated, and the rate of sperm abnormality, the changes of the lipid peroxide, the enzyme activity and the hormone in male rats were observed. With the negative and positive control group, the healthy rats were respectively given by gavage triptolide suspension at the dose of 0.025, 0.05, 0.1 mg x kg(-1) for 30 days. Then the rats were killed for the measurement of the indicators in testis and serum, as well as the study on the sperm abnormality. The results showed that the positive control group had significant difference, compared with the negative control group. The content of SOD, LDH, G-6-PD, Na+ -K+ -ATPase, Ca+ -Mg+ -ATPase decreased significantly in 0.05 mg x kg(-1) group, and reduced more obviously with exposure to the dose of 0.1 mg x kg(-1). The levels of GSH-Px and beta-G showed a significant decrease in the testis of rats only at the dose of 0.1 mg x kg(-1). Nevertheless, the MDA levels, the FSH levels and the LH levels showed no significant difference. The deformity rate of sperm increased significantly in 0.05 mg x kg(-1) group and 0.1 mg x kg(-1) group. The results indicated the triptolide had the effect of the lipid peroxidation to damage Spermatogenic cells, Sertolis cells and Leydig cells. At the same time, the triptolide interfered not only with the energy supply process of aerobic and anaerobic glycolysis,but also with the energy utilization in testis by affecting the activities of testis marker enzymes, and produced a damage chain of the male reproductive system
Animals ; Diterpenes ; toxicity ; Drugs, Chinese Herbal ; toxicity ; Epoxy Compounds ; toxicity ; Lipid Peroxidation ; drug effects ; Male ; Organ Size ; drug effects ; Phenanthrenes ; toxicity ; Rats ; Rats, Wistar ; Reproduction ; drug effects ; Spermatozoa ; abnormalities ; drug effects ; metabolism ; Testis ; drug effects ; growth & development ; metabolism ; Tripterygium ; chemistry ; toxicity

AIMTo investigate the effects of 17beta-estradiol (E2), Peganum harmala extract (PHE) and caloric restriction (CR) on various testis parameters during aging.

METHODSTwelve month-old male rats were treated for 6 months with either E2 or PHE, or submitted to CR (40%).

RESULTSOur results show that estrogens and CR are able to protect the male gonad by preventing the decrease of testosterone and E2 levels as well as the decrease of aromatase and estrogen receptor gene expressions. Indeed, E2, PHE and CR treatments induced an increase in the superoxide dismutase activities and decreased the activity of testicular enzymes: gamma-glutamyl transferase, alkaline phosphatase, lactate deshydrogenase as well as the aspartate and lactate transaminases in aged animals. In addition, the testicular catalase and gluthatione peroxidase activities were enhanced in E2, PHE and CR-treated rats compared to untreated animals at 18 months of age. Moreover, the positive effects of estradiol, PHE and CR were further supported by a lower level of lipid peroxidation. Recovery of spermatogenesis was recorded in treated rats.

CONCLUSIONBesides a low caloric diet which is beneficial for spermatogenesis, a protective antioxydant role of estrogens is suggested. Estrogens delay testicular cell damage, which leads to functional senescence and, therefore, estrogens are helpful in protecting the reproductive functions from the adverse effects exerted by reactive oxygen species (ROS) produced in large quantities in the aged testis.

Aging ; physiology ; Animals ; Antioxidants ; metabolism ; Aromatase ; biosynthesis ; genetics ; Caloric Restriction ; Estradiol ; metabolism ; pharmacology ; Estrogens ; pharmacology ; Lipid Peroxidation ; drug effects ; Male ; Oxidative Stress ; drug effects ; Peganum ; chemistry ; Plant Extracts ; pharmacology ; RNA ; biosynthesis ; genetics ; Rats ; Rats, Wistar ; Receptors, Estrogen ; biosynthesis ; genetics ; Testis ; drug effects ; enzymology ; growth & development ; Testosterone ; metabolism ; Thiobarbituric Acid Reactive Substances ; metabolism