Angiotensin-converting enzyme functions in the male reproductive system, but the extent of its function in reproduction is not fully understood. The primary objective of this work was to investigate the relationship between the testicular isoform of angiotensin-converting enzyme present in human spermatozoa and semen parameters, human embryo quality, and assisted reproduction success. A total of 81 semen samples and 635 embryos from couples undergoing oocyte donation cycles at the IVI Bilbao Clinic were analyzed. Semen parameters, embryos quality, and blastocyst development were examined according to the World Health Organization standards and the Spanish Association of Reproduction Biology Studies criteria. The percentage of testicular angiotensin-converting enzyme-positive spermatozoa and the number of molecules per spermatozoon were analyzed by flow cytometry. Both parameters were inversely correlated with human sperm motility. Higher percentages of testicular angiotensin-converting enzyme-positive spermatozoa together with fewer enzyme molecules per spermatozoon were positively correlated with better embryo quality and development. Our results suggest that embryos with a higher implantation potential come from semen samples with higher percentages of testicular angiotensin-converting enzyme-positive cells and fewer enzyme molecules per spermatozoon. Based on these findings, we propose that testicular angiotensin-converting enzyme could be used to aid embryologists in selecting better semen samples for obtaining high-quality blastocysts during in vitro fertilization procedures.
Adult ; Embryo Implantation/physiology* ; Embryo Transfer ; Embryonic Development/physiology* ; Fertility/physiology* ; Fertilization in Vitro ; Humans ; Male ; Middle Aged ; Peptidyl-Dipeptidase A/metabolism* ; Sperm Motility/physiology* ; Spermatozoa/enzymology* ; Testis/enzymology*

The evaluation of infertility in males consists of physical examination and semen analyses. Standardized semen analyses depend on the descriptive analysis of sperm motility, morphology, and concentration, with a threshold level that must be surpassed to be considered a fertile spermatozoon. Nonetheless, these conventional parameters are not satisfactory for clinicians since 25% of infertility cases worldwide remain unexplained. Therefore, newer tests methods have been established to investigate sperm physiology and functions by monitoring characteristics such as motility, capacitation, the acrosome reaction, reactive oxygen species, sperm DNA damage, chromatin structure, zona pellucida binding, and sperm-oocyte fusion. After the introduction of intracytoplasmic sperm injection technique, sperm maturity, morphology, and aneuploidy conditions have gotten more attention for investigating unexplained male infertility. In the present article, recent advancements in research regarding the utilization of male fertility prediction tests and their role and accuracy are reviewed.
Acrosome Reaction ; Aneuploidy ; Chromatin ; DNA Damage ; Fertility* ; Humans ; Infertility ; Infertility, Male ; Male* ; Physical Examination ; Physiology ; Reactive Oxygen Species ; Semen Analysis ; Sperm Injections, Intracytoplasmic ; Sperm Motility ; Spermatozoa ; Zona Pellucida

Epigenetic factors play an important role in male infertility though about 60%－65% of the disease is idiopathic and its underlying causes are not yet clear. Many studies have indicated that epigenetic modifications, including DNA methylation, histone tail modifications, chromatin remodeling, and non-coding RNAs, may be involved in idiopathic male infertility. Abnormal methylation is associated with decreased sperm quality and fertility. It is known that 1 881 miRNAs are related to male fertility and such non-coding RNAs as piRNA, IncRNA, and circRNA play a regulating role in male reproduction. This review focuses on the value of epigenetics in the etiology and pathogenesis of male infertility, aiming to provide some evidence for the establishment of some strategies for the treatment and prediction of the disease.
DNA Methylation ; Epigenesis, Genetic ; Fertility ; Humans ; Infertility, Male ; genetics ; Male ; MicroRNAs ; physiology ; RNA, Small Interfering ; Spermatozoa

The objective of this study was to investigate factors that influence the success of resynchronization protocols for bovines with and without progesterone supplementation. Cow synchronized and not found pregnant were randomly assigned to two resynchronization protocols: ovsynch without progesterone (P4) supplementation (n = 66) or with exogenous P4 administered from Days 0 to 7 (n = 67). Progesterone levels were measured on Days 0 and 7 of these protocols as well as 4 and 5 days post-insemination. Progesterone supplementation raised the P4 levels on Day 7 (p < 0.05), but had no overall effect on resynchronization rates (RRs) or pregnancy per artificial insemination (P/AI). However, cows with Body Condition Score (BCS) > 3.5 had increased P/AI values while cows with BCS < 2.75 had decreased P/AI rates after P4 supplementation. Primiparous cows had higher P4 values on Day 7 than pluriparous animals (p = 0.04) and tended to have higher RRs (p = 0.06). Results of this study indicate that progesterone supplementation in resynchronization protocols has minimal effects on outcomes. Parity had an effect on the levels of circulating progesterone at initiation of the protocol, which in turn influenced the RR.
Animals ; Cattle/*physiology ; Dinoprost/administration & dosage/*pharmacology ; Estrus Synchronization/*drug effects/methods ; Female ; Fertility Agents/administration & dosage/pharmacology ; Gonadotropin-Releasing Hormone/administration & dosage/*pharmacology ; Insemination, Artificial/veterinary ; Ovulation/drug effects ; Pregnancy ; Progesterone/administration & dosage/*pharmacology ; Tromethamine/administration & dosage/*pharmacology

OBJECTIVETo study the influence of lipopolysaccharide (LPS)-induced inflammation on the testicular histology and reproductive endocrine function in male rats and investigate the possible mechanism of inflammation affecting male fertility.

METHODSThirty-six male SD rats were randomly divided into a control group (A) and three LPS intervention groups (B, C, and D) to receive saline and LPS (5 mg/kg i. p, once), respectively. The animals in groups B, C, and D were killed by anesthesia at 12, 24, and 72 hours after treatment. Histopathological changes in the left testis of the rats were observed by HE staining and the levels of the reproductive hormones T, FSH, and LH in the serum were determined by ELISA.

RESULTSCompared with group B, group A showed clear structure of seminiferous tubules, orderly arrangement of spermatogenic cells, a slightly decreased number of sperm in some seminiferous tubular lumens, and shed spermatogenic cells in the rat testis tissue; group C exhibited thinner seminiferous epithelia, disordered structure of seminiferous tubules, irregular arrangement of spermatogenic cells, decreased number of mature sperm and obvious shedding of spermatogenic cells in seminiferous tubular lumens; group D manifested similar findings to those of group C, with even more shed spermatogenic cells that blocked the tubular lumens. The levels of serum T, LH, and FSH were (0.490 +/- 0.028) ng/ml, (6.290 +/- 0.515) ng/L, and (1.837 +/- 0.127) IU/L in group A, (0.460 +/- 0.024) ng/ml, (5.881 +/- 0.124) ng/L, and (1.707 +/- 0.098) IU/L in group B, (0.417 +/- 0.021) ng/ml, (5.123 +/- 0.271) ng/L, and (1.620 +/- 0.115) IU/L in group C, and (0.378 +/- 0.021) ng/ml, (4.504 +/- 0.279) ng/L and (1.562 +/- 0.216) IU/L in group D, all decreased in group B as compared with A (P > 0.05). The decreases of T and LH were extremely significant (P < 0.01) and that of FSH was significant in groups C and D (P < 0.05) in comparison with A.

CONCLUSIONLPS-induced inflammation affects the testicular tissue and reproductive endocrine function of male rats, resulting in decreased levels of serum T, LH, and FSH.

Animals ; Endocrine System ; drug effects ; physiology ; Fertility ; drug effects ; physiology ; Follicle Stimulating Hormone ; blood ; Humans ; Lipopolysaccharides ; toxicity ; Luteinizing Hormone ; blood ; Male ; Random Allocation ; Rats ; Reproduction ; Seminiferous Tubules ; drug effects ; pathology ; Spermatocytes ; drug effects ; Testis ; drug effects ; pathology ; Testosterone ; blood

In recent years, the variation trend of male fertility and semen parameters has aroused much academic controversy and become a focus of public attention. For the assessment of male fertility, female pregnancy is regarded as a gold standard, but semen parameters are commonly used as surrogate or indirect evidence in clinical practice and laboratory research. The reference range of se- men parameters being used in China is based on the WHO recommended data and lacks the specific reference value for healthy Chinese men. No definite conclusion has yet been derived from studies at home and abroad on the general variation trend of semen parameters worldwide, but many researchers agree on the decline of semen quality in some areas of the world. Long-term continuous prospective studies are needed for the evaluation and prediction of the general variation trend of semen quality.
Asian Continental Ancestry Group ; China ; Female ; Fertility ; Humans ; Male ; Pregnancy ; Prospective Studies ; Reference Values ; Semen ; physiology ; Semen Analysis ; standards ; Sperm Count ; World Health Organization

Adult ; Endometrial Neoplasms ; surgery ; Female ; Fertility ; physiology ; Humans ; Laparoscopy ; Pregnancy ; Pregnancy Outcome ; Sarcoma, Endometrial Stromal ; surgery

The circadian clock has been linked to female reproductive physiology and endocrine in mammals. Epidemiological studies of female shift workers have shown increased rates of abnormal reproduction and adverse pregnancy. But little is known how the circadian rhythms affect reproduction. The aim of the present study was to investigate the influences of circadian rhythms on estrous cycle in female mice using clock gene Rev-erb-α knock out (Rev-erb-α(-/-)) mice. To test the fertility of Rev-erb-α(-/-) mice, litter sizes were counted after mating with C57BL/6J male mice. HE staining was used to observe the change of follicle development. The number of embryos of Rev-erb-α(+/+) and Rev-erb-α(-/-) female mice was compared 1.5 d after mating with C57BL/6J male mice. Then Rev-erb-α(+/+) and Rev-erb-α(-/-) female mice were housed to adult, and daily vaginal lavage with 0.9% saline was used to monitor estrous cycle for at least 30 days. Quantity of various cells was counted on specified smears views after staining. We observed estrous cycles of Rev-erb-α(+/+) and Rev-erb-α(-/-) female mice using line plots and periodic spectrograms. The results showed that the Rev-erb-α(-/-) female mice were infertility, and the number of embryos of Rev-erb-α(-/-) females was less than that of Rev-erb-α(+/+) females. However, the follicle development of Rev-erb-α(-/-) female mice was normal. The estrous cycle of Rev-erb-α(-/-) female mice was 3.22 days longer than that of Rev-erb-α(+/+) female mice. The results suggest that loss of Rev-erb-α prolongs estrous cycle, which is probably one of the reasons for female mice infertility, and circadian rhythm is important for mammalian estrous cycle.
Animals ; Circadian Rhythm ; Estrous Cycle ; Female ; Fertility ; Litter Size ; Male ; Mice ; Mice, Inbred C57BL ; Mice, Knockout ; Nuclear Receptor Subfamily 1, Group D, Member 1 ; genetics ; physiology ; Pregnancy

Progesterone, as a female hormone, plays an important role in the physiological function and pregnancy maintenance in women. Recent studies show that progesterone and its receptor are also involved in male reproduction, and its receptor mRNA exists in male sexual glands. It is believed that progesterone, binding to its receptor, can regulate spermatogenesis and improve the fertilization of sperm, while the sperm from those with oligospermia, asthenozoospermia, teratospermia or unexplained infertility exhibit a low fertility due to the deficient expression of the progesterone receptor and insensitive reaction to progesterone. This review focuses on the progress in the studies of progesterone and its receptor in male reproduction.
Fertility ; Humans ; Male ; Progesterone ; physiology ; Receptors, Progesterone ; physiology ; Spermatogenesis ; Spermatozoa ; physiology ; Testis ; metabolism

OBJECTIVE: To evaluate the clinical effect of letrozole (LE) alone on the ovulation induction in endometrial preparation for frozen-thawed embryo transfer (FET). METHODS: Totally 253 FET cycles were analyzed by case control study from October 2010 to June 2011. We divided ovulation disorders or menstrual disorders divided into 2 groups: a LE group on ovulation induction cycle (n=85), and a hormone replacement therapy (HRT) cycle group (n=84). Meanwhile those who ovulated normally were included in a natural cycle group (n=84). Demographics and clinical parameters of reproductive correlation of all patients were observed among these groups. RESULTS: The average clinical pregnancy rate of the LE group was higher than that of HRT cycle group (54.1% vs 44.04%; P<0.05). The difference in the parameters such as patients' demographics and other clinical indexs had no statistical significance (P>0.05). The estradiol level on human chorionic gonadotrophin (HCG) administration day in the natural cycle group [(341.19±113.14) pg/mL] was higher than that of the LE group [(279.70±127.80) pg/mL] (P<0.05). There was no significant difference in the number of maturation follicles and endometrial thickness on the HCG administration day between the LE group and the natural cycle group (P>0.05). CONCLUSION Ovulation induction with LE alone for endometrial preparation is superior to HRT cycle in FET and has similar clinical process and outcome to those of the natural cycle. It can be applied in endometrial preparation for FET effectively for those with anovulation or menstrual disorder.
Case-Control Studies ; Cryopreservation ; Embryo Transfer ; Endometrium ; drug effects ; physiology ; Female ; Fertility Agents, Female ; therapeutic use ; Fertilization in Vitro ; Humans ; Letrozole ; Nitriles ; therapeutic use ; Ovulation Induction ; methods ; Triazoles ; therapeutic use