Localization of Ureaplasma Urealyticum on Human Spermatozoa

Semen specimens were collected from 20 normal fertile men and 20 unexplained infertile men with U reaplasma urealyticum (U.U.) in semen. Spermatozoa of both groups were examined by immunogold technique and immunofluorescence test. A number of gold particles of the U. U. adhered to the sperm surface of infertile men were observed. Strong specific fluorescence was noticed on the sperm surface of infertile men, mostly on the midpiece and/ or postacrosomal region. A significant increase of sperm morphological abnormality, especially the swollen midpiece, the coiled tail, and head-tail angalation sperms was observed in infertile group. The sperm motility in infertile group is dramatically lower than that infertile group, It is hypothesized that teratospermia, poor motility and interference with sperm-ovum interaction might be the possible mechanisms for male infertility caused by Ureaplasma urealyticum.     

Ureaplasma Urealyticum or Mycoplasma Hominis Infections and Semen Quality of Infertile Men in Abidjan

Objective To determine the prevalence of U. urealyticum and M. hominis in semen samples collected from men admitted in clinic for infertility, and to compare the quality of these semen samples.
Methods A total of 1 058 semen samples collected were investigated. Sperm semiological assays were performed according to the guidelines of the World Health Organisation （WHO）. Semen were examined by Mycoplasma IST for the detection of mycoplasma. Semen culture on agar media was used to detect other microorganisms. Chlamydia was detected using direct fluorescent assay （DFA） of Clamydia Trachomatis.
Results Among 1 058 semen samples, microorganisms were detected in 638 （60.3%）. The infected sperms consisted of mycoplasma alone in 507 cases （47.9%）, mycoplasma and other microorganisms in 98 （9.3%）, giving in all 605 （57.2%） samples infected with mycoplasma. The last 33 （3.1%） consisted of other microorganisms alone. The frequency of U. urealyticum, M. hominis and mixed genital infections detected in semen samples of infertile men were 39%, 23.8% and 5.6%, respectively. The rates of abnormal semen parameters recorded among patients infected with mycoplasma were for volume （22.2%-25%）, viscosity （29.6%-43.5%）, pH （64.7%-72.9%）, motility （80.8%-93.8%）, morphology （36.3%-47.9%）, sperm concentration （53.3%-58.3%） and leukocyte count （51.4%-58.3%）.
Conclusion Frequency of U. urealyticum infection was higher than that of M. hominis. Mycoplasma infections were associated with disorders of pH, motility and sperm concentration. In addition M. hominis infection affected spermatozoa morphology. Therefore, screening of U. urealyticum clinically relevant in Abidjan. and M. hominis for routine semen analysis is     

Association of Ureaplasma urealyticum colonization with development of bronchopulmonary dysplasia: A systemic review and meta-analysis

There is controversy regarding the roles of Ureaplasma urealyticum （U. urealyticum） colo- nization in the development of hronchopulmonary dysplasia （BPD）. This study explored the association between U. urealyticum and bronchopulmonary dysplasia at 36 weeks post-menstrual age （BPD36）. Studies published before December 31, 2013 were searched from Medline, Embase, Ovid, Web of Sci- ence, and Cochrane databases, with the terms ＂Ureaplasma urealyticum＂, ＂chronic lung disease＂, or ＂BPD36＂ used, and English language as a limit. The association between U. urealyticum colonization and BPD36 was analyzed with RevMan 4.2.10 software, using the odds ratio （OR） and relative risk （RR） for dichotomous variables. Out of the enrolled 81 studies, 11 investigated the BPD36 in total 1193 in- fants. Pooled studies showed no association between U. urealyticum colonization and subsequent de- velopment of BPD36, with the OR and RR being 1.03 （95% CI=0.78-1.37; P=-0.84） and 1.01 （95% CI= 0.88-1.16, P=-0.84）, respectively. These findings indicated no association between U. urealyticum colo- nization and the development of BPD36.     

Effects of Multiglycoside of Tripterygium Wilfordii （GTW） on Spermatogenic Ceils and Enzymatic Activities in Male Rats

This study was undertaken to observe consecutively the morphology of testis and epididymis and the changes of enzymatic activities of AKP, ACP, 3β-HSD and LDH-C4 in male rats treated with GTW 30 to 80 days. In addition, male antifertility effect and its possible reversibility were also observed. The results showed that GTW is a potential testicular toxicant in the animals. It can cause damage of the sperm cells with close relation to the treated time and dosage, Sloughing of sperm cells and many multinucleated giant cells in the seminiferous tubules were found on day 40 and 50 after the treatment. The tubules were hyperatrophic and the sperm cells were almost absent at the end of the study(80 days), No obvious morphological alteration was observed in the epididymal epithelial tissue, But changes of quality and number df the spermatozoa in epididymides were found prior to those of testes. Reduced number and abnormal cauda sperm were observed 30 days after the treatment, The ACP activity of Sertoli cells increased slightly, whereas the activities of ACP and LDH-C4 decreased gradually as the treated time prolonged. The 3β-HSD of Leydig cells was changed or subtle by m-phase or treatment and dramatically decreased at the end of treatment, The infertility caused by GTW was reversible 8 weeks after cessation of the treatment.     

Effects of cadmium on rat sperm motility evaluated with computer assisted sperm analysis

Objective:To study effects of cadmium on rat sperm motility evaluated with computer assisted sperm analysis.Methods:Different doses of cadmium chloride(0.2,0.4,0.8mg Cd/kg BW) were administrated ip to adult male Sprague-Dawley rats.Control animals received the same volume of 0.9% NaCl solution.After 7 days,the rats were sacrificed with their testes removed.A part of one testis was used for testicular sperm head counts and daily sperm production observation.The motility of spermatozoa obtained from cauda epididymides using the “diffusion“ method was measured by computer assisted sperm analysis(CASA).Results:The sperm head Counts and Daily Sperm production decreased significantly in the high dose group.The motility of spermatozoa in the middle ose group was reduced significantly.No motile sperm was found in the high dose group.The results suggest that germinal epithelium was impaired irreversibly in a short time to produce toxic effects on spermatogenesis at high cadmium doses.Conclusion:Cadmium may reduce sperm motility at a dose far below the dose affecting sperm production at this time point.The motiligy of sperm is an early and sensitive endpoint for the assessment of cadmium toxicity on male reproduction.     

Evaluation on Sensitivity of the Human Sperm Motility Assay for Detecting Endotoxin in Culture Medium

Objective To investigate the sensitivity of the human sperm motility assay for detecting endotoxin in culture mediumMaterials &. Methods Motile sperm were separated and exposed to different concentrations of endotoxin (0.5 ng/mL, 1ng/mL, 10ng/mL, 1000ng/mL, 10 000ng/ mL, and 50 000ng/mL), and sperm motility was determined after incubation. Effects of endotoxin on sperm motility in media without albumin were also examined. In addition, at the same concentrations of endotoxin (0. 5ng/mL, 1 ng/mL, and 10 ng/ mL ) , the sensitivity of the human sperm motility assay was compared to those of 1-cell and 2-cell mouse embryo bioassays.Results At levels of 0. 5ng/mL-1000ng/mL endotoxin in media with 2mg/mL albumin, sperm did not show significant change in motility during 24 h of incubation when compared with the control (P>0. 05). However, the sperm motility was significantly inhibited at endotoxin dosages of 10 000 and 50 000 ng/mL. In the absence of albumin supplementation, at endotoxin levels of 50 000ng/mL, a     

<Emphasis Type="Italic">Attractin</Emphasis> gene deficiency contributes to testis vacuolization and sperm dysfunction in male mice

The effect of loss-of-function of Attractin （Atrn） on the male mouse reproduction system was examined in the study. The weights and pathological changes of testes and epididymes were compared between Atrn mutant （Atrnmg-3J） mice and wild-type mice （C3HeB/FeJ） at different months of age. The number and motility of sperms were measured in the mutant and control mice. Furthermore, the testicular lactate dehydrogenase （LDH） and succinate dehydrogenase （SDH） in these animals were detected. The fertility potential of the sperms was observed in vivo and in vitro. The results showed that the testes of 3-month-old Atrnmg-3J mice experienced no significantly different pathological changes from the control mice at the same month of age but the SDH activity was substantially reduced. In the 5-month-old mutant mice, as compared with the control mice, mild vacuolation was found in the testes, the density and motility of sperms were decreased in the epididymes, the sperm fertility was impaired and the testicular enzyme activity was reduced. It is concluded that the age-related Atrn gene progressively loses its function and can cause testis vacuolation and impaired sperm function, which may be responsible for the impairment of male reproductive ability.     

Effect of Wuziyanzong Pill on sperm quality and calcium ion content in oligoasthenospermia rats

OBJECTIVE:To study the effect of Wuziyanzong treatment on the sperm quality and content of calcium ions(Ca 2+) in oligoasthenospermia rats.METHODS:A model of oligoasthenospermia was induced in 50 Sprague Dawley rats by treatment with tripterygium glycosides at 30 mg/kg per day for 8 weeks.They were divided randomly into a model group,a positive group(Huangjingzanyu capsule,3.01 g/kg),and low,medium and high dose Wuziyanzong treatment groups(2.30,4.60,9.20 g/kg crude drug respectively) with 10 in each group.Another 10 rats were used as a control group.The rats in the control and model groups were administered distilled water,while the rats in the remaining groups were administered Wuziyanzong for 30 d.The epididymides were removed,spermatozoa recovered and the sperm density and viability were measured.The spermatozoa were purified and the contents of Ca 2+ in the cytoplasm and mitochondria were detected by flow cytometry and atomic absorption spectrometry,respectively.RESULTS:After 8 weeks of treatment with tripterygium glycosides,the sperm density,sperm activity and the Ca 2 + content of spermatozoa in the model rats were all significantly decreased compared with the control group(all P<0.05).After 30 d treatment,the sperm density and activity improved and the Ca 2 + content of sperm were increased significantly in the medium and high dose Wuziyanzong treatment groups in comparison with the model group(all P<0.05).CONCLUSION:The Wuziyanzong treatment increased sperm density,improved sperm viability and enhanced the content of Ca 2+ in the sperm cytoplasm and mitochondria in this rat model of oligoasthenospermia.     

Cold—preserved human spermatozoa in electrolyte—free solution retain their penetration capacity

Objective: To evaluate penetration capacity of human sperm preserved in electrolyte-free (EF) solution at 4 ℃. Methods: The motility, acrosomal status penetration rate and fertility index of human sperm were assessed before and after cold-preservation in EF solution, respectively. Results: The motility of human sperm cold-preserved in EF solution for 1 week was significantly higher than that of human sperm cold-preserved in modified human tubal fluid ( mHTF) (43. 4% ± 7. 9% vs 9. 5% ±2. 5% , P <0. 01 ). Although acrosomal status of human sperm cold-preserved in the EF solution before reinitiation was not different from those of the fresh sperm ( capacitated sperm; 7. 6% ± 1. 8% vs6.4±1.8%; acrosome-reacted sperm; 3.0% ±1.7% vs2.4±1.1%, P>0.05), the percentage of capacitated and acrosome-reacted sperm in the EF solution significantly increased after reinitiation (capacitated sperm; 16. 0% ± 2.3%vs7.6±1.8%, acrosome-reacted sperm: 9. 4% ±2.1% vs 3. 0% ±1.7%, P<0.01). The penetration rate and fe     

Effects of Malachite Green on the Development of Mouse Embryo In Vitro

Objective To observe effects of malachite green （MG） on the development of mouse embryo in vitro.Methods Two-cell mouse embryos were obtained and exposed to different concentrations of MG （0 ng/ml, group A, the control; 10 ng/ml, group B; 100 ng/ml, group C; 1 000 ng/ml, group D）. The 2-cell mouse embryo assay was used to determine the 2-cell embryo development to the blastocyst. In addition, at the same concentrations of MG, the human sperm motility assay was used to evaluate the influence of MG on sperm viability.Results At the 8-cell stage, groups C and D showed inhibitory effects when compared with the control （P〈0.01）. Rate of the blastocyst in groups C and D was lower than that of the control （P〈O.O1）. In the sperm motility assay, significant changes in motility after 24 h of incubation in groups C and D were observed compared with the control （P〈0. 01）. However, no differences were found on 24 h sperm motility between group B and the control （P〉0.05）. Conclusion MG would have deleterious effects on the development of mouse embryo, and the effects were dose-related. The sperm motility assay could also detect high levels of MG in culture medium.     

Identification of an 80 K Dalton Human Sperm Antigen

Monoclonal antibodies raised against human sperm were used as a probe to look for specific human sperm antigen. By “ Western blotting” ,an 80 K dalton molecular weight protein was recognized by the monoclonal antibody, 21-2-4. By the SDS polyacrylamide gel electrophoresis, the 80 Kd was the major band of deoxycholate extract in which this protein could be isolated from other components of sperm by eleetro-elution from the gel slab. For the purpose of evaluating the function of 80 Kd in fertilization, the rabbit anti-80 Kd polyclonal antibodies were produced and immunoassays were performed. The TAT result showed that the agglutination in patterns of tail to tail and head to head were induced by incubating human sperm with rabbit anti-8OKd antiserum. The SIT result showed that the human sperm motility was strongly inhibited by rabbit anti-80 Kd antiserum. The immanofluorescence staining of human sperm incubated with rabbit anti-80 Kd antiserum showed very strong fluorescence on postaerosome and tail. These results suggest that 80 Kd is a specific sperm antigen which locates on the surface of human sperm and possibly plays an important role in fertilization.     

Effects of Murine Cytomegalovirus Infection on Sperm Viability in Mice

In order to explore the effects of testicular infection of murine cytomegalovirus （MCMV） on mature sperm viability at different periods following MCMV inoculation in mice, 91 BALB/c mice without MCMV infection were randomly divided into two groups： an experimental group （n= 56） and a control group （n=35）. The mice in the experimental group were treated by inoculating MCMV intratesticularly, while those in the controlled group were directly inoculated with DMEM without MCMV. The mice in both groups were sacrificed separately on the day 1,1.5, 2, 4, 6, 9 and 14 post-inoculation （D1, 1.5, 2, 4, 6, 9 and 14 PI）. The MCMV M83 mRNA gene was detected in the testis by in situ hybridization （ISH） with MCMV late-mRNA probe labeled with digoxin. Sperm viability of mature sperm in the epididymis cauda was measured. The results demonstrated the positive signal of ISH of MCMV was found mainly in the cytoplasm of the testicular interstitial cells and spermatogenic cells in the experimental group. Compared with that in the controlled group, the sperm viability in the experimental group was decreased significantly on D1 PI and D1.5 PI （P〈 0.05）. No statistically significant difference in the sperm viability was found after D2 PI between two groups （P〉0.05）. This suggested that sperm viability in mice might be descended significantly shortly after MCMV infection and might return to normal with time, indicating that MCMV acute infection might temporarily degrade sperm quality and influence procreation transiently.     

Antisperm Antibodies on the Surface of Spermatozoa before＇Ejaculation from Vasectomized Men

The antisperm antibodies (AsAbs) coated on spermatozoa of the proximal vas deferens (sperm before ejaculation, SBE) from 48 fertile men who were volunteers of vasectomy and 24 vasectomized men who asked for vasovasotomy,were determined by immunobead test (IBT) and sperm cervical mucus contact test (SCMC). The results showed that in fertile men there were no positive sam ples of SBE in IBT and SCMC. In vasectomized men positive samples of SBE were found in 79.4% for IgG, 38.2% for IgA and 35.5% for SCMC. The AsAbs on SBE could be found at the time of less than one year to more than 3 years after vasectomy. The AsAbs were still found on the semen samples at 1-3 months after vasovasotomy. Our results also indicated that the incidence of AsAbs on SBE from vasectomized men could not predict the levels of AsAbs on their ejaculated sperm after vasovasotomy. There was no significant correlation between the levels of AsAbs in serium before vasovasotomy and those on SBE from vasectomized men.     

Anti-spermatogenic Effects of Ethanol Extract of Mucuna Urens

Objective To investigate the age-long claim by the locales that the food thickener, M. urens seed, has antispermatogenic, hence, antifertility effects in man. Methods Eight-week old male Albino rats were used as the mammalian model for this study. They were assigned to four groups of 6 rats each and treatment with the ethanol extract was for a period of 14 d. The treatment regimes were 70 mg/kg, 140 mg/kg, 210 mg/kg and 0 mg/kg BW in groups A, B, C and D, respectively. Extracts were prepared by Soxhlet extraction using 80% ethanol as the extracting solvent. The stock solution was prepared by dissolving 1 g of the paste extract in 10 ml corn oil （vehicle） to make up 100 mg/ml concentration. At the end of the treatment, sperm from the distal caudal epididymis was collected and analyzed for sperm count, sperm motility and sperm morphology. Results Significant reduction was observed in sperm count and sperm motility （P〈0.05）. The mean sperm count for group A was 6.27±0.02×10^6, for group B was 6.16±0.02×10^6 and group C had 6.0±0.0×10^6 sperm cells The control （group D） had a mean sperm count of 6.50±0.09×10^6 which was higher than that of any treated group. Results of the sperm motility test gave the following mean rates for motile sperm cells after treatment： group A, 57.6±% 2.1; group B, 50.0±4.0; group C, 45.0±4.0. The control had the highest mean motility rate of 72.3±2.1. The observed sperm abnormalities included unusual head with large acrosome, looped tailpiece, mid piece with distal droplet, pin head, pyriform head and long hook.Conclusion The anti-spermatogenic effects of the extract on the sperm in the Albino rat may lead to reduction of fertility.     

GOSSYPOL-INDUCED ALTERATIONS OF AMINOPHOSPHOLIPID COMPOSITION IN HUMAN SPERM

Gossypol-induced alterations of aminophospholipid composition in human sperm wereobserved and the effects of some factors on these alterations were investigated.The altera-tions of aminophospholipid composition of human sperm induced by gossypoI included aprogressive decrease in the levels of phosphatidylethanolamine(PE)and phosphatidylserine(PS)when gossypol concentrations ranged from 5-500μmol/L,and a progressive increase inthe level of(LPE)at lower gossypol concentrations(5-50μmol/L).The conversion of PEinto lysophosphatidylethanolamine(LPE)was strongly enhanced by Ca~(2 )and inhibitedby 0.5mmol/L EDTA,while PMSF,NEM,iodoacetamide and Zn~(2 )had no effect.Thisconversion was weaker in sperm with stripped surface proteins than in normal sperm.In addition,three surface proteins(MW 80,60 and 40 kD)were fixed on the plasmamembrane by gossypol treatment.The significance of gossypol action and the possibilitythat sperm PLA_2, PE and.some surface proteins might play an important role in the physio-logical acrosome reaetion of human sperm,as well as in oocyte penetration,are discussed.     

Effect of Anthocleista djalonensis A. Chev Root Extract on Testis of Matured Rats

Objective: To investigate the effects of different extracts of Anthocleista djalonensis on the testis and epididymal sperms of rats. Methods: Fifty male Wistar rats were randomly divided into 10 groups (n=5 in each group) and orally treated with 50, 100 and 200 mg/kg body weight each of methanol, aqueous ethanol (H-EtOH) and chloroform extracts of A. djalonensis. Corn oil was used as vehicle (2 mL/kg). After 60 days of treatment, testosterone (T) and cholesterol (CHOL) concentrations, catalase (CAT), lactate dehydrogenase (LDH), 3β -hydroxysteroid dehydrogenase (3β -HSD) and superoxide dismutase (SOD) activities in the testes along with myeloperoxidase (MPO) activities and nitrite concentrations (NO) in the serum and testes as well as sperm quality were measured. Results: T and CHOL concentrations along with 3β -HSD activity were significantly higher in the animals treated with the low dose than in those treated with the high dose of the chloroform extract (P<0.05). Furthermore, the chloroform extract was more effective than the methanol extract that had the most marginal effect on T level at the high dose and the H-EtOH extract that was only effective at the medium dose. LDH activity was dose-dependently increased by the extracts in all groups. The CAT-SOD antioxidant system was increased in the treated animals at all doses compared to the control values, but the increase in glutathione level reached significant level in those treated with the low dose H-EtOH aqueous ethanol extract (P<0.05). Only the high dose of chloroform extract had significant inhibitory effects on MPO activity (P<0.05). Serum NO concentration was decreased at all doses of the extracts. The inhibitory effects of the extracts on testicular NO concentrations follow this order, chloroform extract > H-EtOH > methanol. Although all extracts at all doses showed excellent stimulatory effects on sperm quality (count, motility and morphology), the methanol extract at the high dose was the most effective on sperm count (P<0.05). Conclusion: The chloroform extract of A. djalonensis has better androgen-like and anti-inflammatory effects whereas the methanol extract has the best effect on sperm count.     

Effects of Placental Isoferritin on the Mouse Embryo Development in vitro

To investigate the effect of placental isoferritin （PLF） on mouse embryo development in vitro, mice 2-cell embryos were co-cultured with human first trimester decidual cells at different concentrations of PLF in vitro. The following changes of the above system were observed under an invert microscope and the number of embryos were recorded and the embryos were classified. The results showed there was no significant difference in the percentage of embryos development to 4-cell 8-cell and morula （P〉0.05）. PLF at the doses of 10 and 100 U/mL significantly enhanced more embryos development to the blastocyst and hatching blastocyst （P〈0.05）. PLF at the dose of 1000 U/mL depressed more embryos development from 2-cell to hatching blastocyst, meanwhile such phenomena as cell degeneration and irregular cleavage were observed in part of embryos, but there was no significant difference in statistics （P〉0.05）. It was concluded that PLF at the concentration of 10-- 100 U/mL had no significant effects on the early development of mice embryos, however, PLF could promote the growth, differentiation, and hatching of preimplantion blastocysts.     

Effect of Electroacupuncture on Spermatogenesis in Rats with Oligozoospermia of Insufficiency of Shen (Kidney) Essence Syndrome

Objective: To assess the effect of electroacupuncture(EA) on expression of cytoskeletal proteins from Sertoli cells(SCs) and spermatogenesis in rats with oligozoospermia of insufficiency of Shen(Kidney)essence syndrome(OIKES).Methods: Twenty healthy male Sprague-Dawley rats were randomly assigned to four groups using a random number table: control,tripterygium glycosides(TG) treatment,sham and EA groups(n=5 in each group).A rat model of OIKES was established by oral gavage with TG.The EA group was treated with TG and received EA at Shenshu(BL 23) and Zusanli(ST 36) acupoints for 20 min,once daily for 30 days,while the sham group received EA at identical acupoints with skin penetration without stimulation.After 30 days,the ?nal body weight and coef?cients for the testis and epididymis were calculated and sperm parameters were measured.Immunohistochemical analyses were performed to detect expression of vimentin and α-tubulin in SCs and proliferating cell nuclear antigen(PCNA) immunoreactivity in germ cells.Apoptosis in germ cells was quanti?ed by the transferase biotin-dUTP nick end labeling assay.Results: Compared with the control group,the final body weight and testis/epididymis coefficients of rats in the TG-treated group were not significantly different,but the sperm count and motility were lower(P0.05).Expressions of vimentin and α-tubulin were also signi?cantly weaker(P0.01).The PCNA immunoreactivity of germ cells was decreased(P=0.059),whereas the apoptotic index of germ cells was increased signi?cantly(P0.01).In contrast,EA at BL 23 and ST 36 acupoints signi?cantly improved the ?nal body weight as well as the sperm count,concentration and motility(P0.01 or P0.05).EA increased expression of vimentin and α-tubulin in SCs markedly,and signi?cantly enhanced PCNA immunoreactivity with decreased apoptosis in germ cells(P0.01 or P0.05).Conclusions: EA at BL 23 and ST 36 acupoints has protective effects on spermatogenesis in rats with OIKES.This effect seems to be achieved by attenuating TG-induced disruption of cytoskeletal protein in SCs.     

Study on the Fluorescent Localization of Seminal Vesicle Secretion Protein Ⅱ on the Surface of Rat Sperm

The binding of seminal vesicle secretion protein Ⅱ (SVP) to rat epididymal sperm surface was studied by means of an indirect immunofluorescent antibody technique. The rat epididymal sperms were incubated with purified SVP Ⅱ then treated with rabbit anti-SVP Ⅱ serum and goat anti-rabbit lgG conjugated to fluorescein isothiocyanate. It was found that the whole sperm surface was coated with fluorescence under the fluorescence microscope, and the fluorescence in the sperm head was the brightest. The conclusion might be therefore that SVP Ⅱ had some ability to bind the epididymal sperm surface and may be one of the components of sperm coating antigen in rats. In addition, it was also demonstrated by immunoabsorption and immunocross-reaction tests that SVP Ⅱ was tissue-specific antigen and there was no cross-reaction with other purified SVP.     

Ultrastructural and immunohistochemical studies on Trichomonas vaginalis adhering to and phagocytizing genitourinary epithelial cells

Background Trichomonas vaginalis (T.vaginalis) belongs to a common sexually transmitted disease pathogen causing genitourinary trichomoniasis in both sexes. We investigated the pathogenetic mechanism of genitourinary trichomoniasis. Methods Cultured T. vaginalis bodies were injected into the vaginas of rats, or incubated with genitourinary epithelial cells of female subjects, male subjects, and sperm. The ultrastructural and microscopic changes were observed via transmission and scanning electron microscopy and through microscopic histochemistry. Results Groups of T.vaginalis adhered to PAS positive columnar cells at the surface of stratified epithelium in the middle and upper portions of the vaginas. They also traversed under these cells. The parasites were shown to be PAS, cathepsin D, and actin positive, and they could release hydrolase into the cytoplasm of adhered epithelial cells. In the amebiform T.vaginalis, microfilaments were arranged into reticular formation. Similar phenomena were found during the interaction of T.vaginalis with host cells, both in vitro and in vivo. Usually several protozoa adhered to an epithelial cell and formed polymorphic pseudopodia or surface invaginations to surround and phagocytize the microvilli or other parts of the epithelial cytoplasm. Adhesion and phagocytosis of sperm by the protozoa occurred at 15-30 minutes of incubation. Digestion of sperm was found at 45-75 minutes and was complete t 90-105 minutes. onclusions T.vaginalis tends to parasitize at the fornix of the vagina, because this is the site here columnar cells are rich in mucinogen granules and their microvilli are helpful for adhesion and ibbling. T.vaginalis possesses some invading and attacking abilities. Shape change, canalization, ncystation, phagocytosis, digestion, the cell coat, cytoskeleton, and lysosome all play important oles in the process of adhesion. They have two methods of phagocytosis: nibbling and ingestion. enitourinary epithelium may be injured directly by the digestive action of hydrolases, phagocytosis, and the mechanical action of pseudopodia.