OBJECTIVETo study the contribution of puberty maturation to smoking behavior in Chinese adolescents.

METHODSA cross-sectional survey was carried out. One thousand four hundred and fifty-three senior middle school students aged from 15 - 18 years were recruited in Shanghai in 2000. A standardized self-administrated questionnaire was designed to obtain information on smoking, age at first nocturnal ejaculation in boys, age at menarche in girls and variables that might be associated with smoking in adolescents.

RESULTSIn boys, the prevalence of experimental smoking was highest among later maturers (28.6%), followed by the earlier (21.3%) and the average (21.7%), and the prevalence of current smoking was highest among earlier maturers (16.4%), followed by the later (7.1%) and then the average (4.8%). In girls, the prevalence of ever smoked among earlier, average and later maturers were as follows: 24.2%, 12.0%, 6.3% respectively. When psychosocial variables which might be associated with smoking were under control, early maturation was a significant risk factor for current smoking in boys (OR = 3.68, 95% CI: 1.23 - 10.99), and might be a risk factor for ever smoked in girls (OR = 2.23, 95% CI: 0.89 - 5.60). Whereas late maturation might have been a risk factor for boys to experiment smoking (OR = 1.48, 95% CI: 0.72 - 3.06), while in girls it might be protective (OR = 0.64, 95% CI: 0.22 - 1.86).

CONCLUSIONEarlier or later matured boys and earlier matured girls were at higher risk of smoking. Pubertal changes and timing need to be considered in smoking prevention.

Adolescent ; Adolescent Behavior ; Female ; Humans ; Male ; Puberty ; physiology ; psychology ; Risk Factors ; Sexual Maturation ; physiology ; Smoking ; epidemiology ; psychology ; Statistics as Topic

Puberty is a pivotal biological process that completes sexual maturation to achieve full reproductive capability. It is a major transformational period of life, whose timing is strongly affected by genetic makeup of the individual, along with various internal and external factors. Although the exact mechanism for initiation of the cascade of molecular events that culminate in puberty is not yet known, the process of pubertal onset involves interaction of numerous complex signaling pathways of hypothalamo-pituitary-testicular (HPT) axis. We developed a classification of the mechanisms involved in male puberty that allowed placing many genes into physiological context. These include (i) hypothalamic development during embryogenesis, (ii) synaptogenesis where gonadotropin releasing hormone (GnRH) neurons form neuronal connections with suprahypothalamic neurons, (iii) maintenance of neuron homeostasis, (iv) regulation of synthesis and secretion of GnRH, (v) appropriate receptors/proteins on neurons governing GnRH production and release, (vi) signaling molecules activated by the receptors, (vii) the synthesis and release of GnRH, (viii) the production and release of gonadotropins, (ix) testicular development, (x) synthesis and release of steroid hormones from testes, and (xi)the action of steroid hormones in downstream effector tissues. Defects in components of this system during embryonic development, childhood/adolescence, or adulthood may disrupt/nullify puberty, leading to long-term male infertility and/or hypogonadism. This review provides a list of 598 genes involved in the development of HPT axis and classified according to this schema. Furthermore, this review identifies a subset of 75 genes for which genetic mutations are reported to delay or disrupt male puberty.
Adolescent ; Male ; Humans ; Adult ; Child ; Gonadotropin-Releasing Hormone ; Gonadotropins/metabolism* ; Hypogonadism ; Testis/metabolism* ; Puberty/physiology* ; Sexual Maturation

OBJECTIVETo investigate the gene expression of Kiss-1 in the hypothalamus of true precocious female rats at various stages of development.

METHODSForty 5-day-old normal female Sprague-Dawley rats were randomly assigned into four groups of 10 rats: Control group 1, Control group 2, Model group 1 and Model group 2. The rats from the two model groups were injected with 300 microg of danazol at 5 days of age to induce true precocious puberty. The two control groups were injected with normal saline instead. For the determination of Kiss-1 mRNA expression in the hypothalamus, the rats of the Model group 1 were sacrificed during the first diestrus (early puberty) and meanwhile the rats of the Control group 1 were sacrificed when they were at prepuberty; the Control group 2 rats were sacrificed at the first diestrus (early puberty); the rats of the Model group 2 were sacrificed during the second diestrus (middle puberty). The expression of Kiss-1 mRNA in the hypothalamus in the four groups was detected using semi-quantitative reverse transcription polymerase chain reaction (RT-PCR).

RESULTSKiss-1 mRNA expression in the hypothalamus in Model group 1 and Model group 2 increased by 1.4-fold and 2.8-fold, respectively, compared with that of Control group 1 (P < 0.05). Model group 2 showed significantly higher Kiss-1 mRNA levels than Model group 1 (P < 0.05). There were no statistical differences in the Kiss-1 mRNA expression between Control group 2 and Model group 1.

CONCLUSIONSGene expression of Kiss-1 is associated with the developmental period of true precocious puberty, suggesting that Kiss-1 might play a role in the pathogenesis of this disorder.

Animals ; Female ; Hypothalamus ; metabolism ; Kisspeptins ; Luteinizing Hormone ; blood ; Proteins ; genetics ; RNA, Messenger ; analysis ; Rats ; Rats, Wistar ; Sexual Maturation ; physiology

The structural change of the oviduct of freshwater shrimp (Macrobrachium nipponense) during spawning was examined by electron microscopy. The oviduct wall structural characteristics seem to be influenced significantly by the spawning process. Before the parturition and ovulation, two types of epithelial cells (types I and II) are found in the epithelium. The free surfaces of type I and type II cells have very dense long microvilli. Under the type I and type II cells, are a relatively thick layer of secreting material and a layer of mostly dead cells. After ovulation, two other types of epithelial cells (types III and IV) are found in the oviduct wall epithelium. The free surface of type III cells only has short microvilli scattered on the surface. The thick layer with secreting material and the dead cell layer disappeared at this stage. In some type III cells, the leaking out of cytoplasm from broken cell membrane led to the death of these type III cells. The transformation of all four types of epithelial cells was in the order: IV-->I-->II-->III.
Adaptation, Physiological ; Animals ; Breeding ; Female ; Fresh Water ; Microscopy, Electron, Scanning ; Oviducts ; physiology ; ultrastructure ; Palaemonidae ; physiology ; ultrastructure ; Reproduction ; physiology ; Sexual Maturation ; physiology

Galectin-3, a member of the beta-galactoside-binding protein family, has been implicated in mammalian sperm maturation. We examined galectin-3 expression in the testis and epididymis of sexually mature and immature bulls. Western blot analysis showed varying levels of galectin-3 in the bull testis and epididymis, and galectin-3 immunoreactivity was higher in the mature testis and epididymis than in immature organs. Galectin-3 was primarily localized in interstitial cells of the immature bull testis and in the peritubular myoid and interstitial cells of the mature testis. In the immature epididymis head, galectin-3 was primarily in the principal and basal cells of the epithelium. In the mature epididymis head, moderate levels of galectin-3 were detected in the sperm, while low levels were found in the stereocilia, epithelium and connective tissue. In the immature epididymis body, moderate protein levels were detected in the principal cells, while lower levels were found in the basal cells. The mature epididymis body showed moderate levels of galectin-3 immunostaining in the stereocilia and epithelium, but low levels in the connective tissue. In the immature epididymis tail, only low levels of galectin-3 staining were found in the epithelium, whereas the mature epididymis tail showed high levels of galectin-3 in the principal cells, moderate levels in the basal cells and low levels in connective tissue. These findings suggest that galectin-3 expression plays a role in the maturation and activation of sperm in bulls.
Aging/physiology ; Animals ; Blotting, Western ; Cattle ; Epididymis/*metabolism ; Galectin 3/*metabolism ; Gene Expression Regulation/physiology ; Immunohistochemistry ; Male ; Sexual Maturation/*physiology ; Testis/*metabolism

Oocytes retrieval, in vitro maturation (IVM) and fertilization (IVF) efficiency are inevitable steps towards in vitro production of embryos. In the present study, these parameters were investigated in the ovaries of prepubertal (n = 31) and pubertal (n = 61) black Bengal goats obtained from a slaughterhouse. Nuclear maturation was evaluated upon aspiration and following IVM in TCM-199 (Earle's salt with L-glutamine and sodium bicarbonate) for 27 h at 39degrees C under 5% CO2 in humidified air. The oocytes retrieval and efficiency (mean +/- SD) per prepubertal and pubertal goats were 5.2 +/- 0.6 and 6.8 +/- 0.6, and 77.3 +/- 0.1% and 80.5 +/- 0.6%, respectively. Anaphase I - telophase I stages differed significantly (7.3 +/- 0.8 vs. 2.6 +/- 0.2, p < 0.05) between the two groups of goats. After IVM, the percentages of metaphase II were significantly higher (66.3 vs. 60.3, p < 0.05) in pubertal goats than in their prepubertal counterparts. The percentages of normal in vitro fertilization (IVF) in Fert-Tyrode's albumin lactate pyruvate of pubertal goat oocytes did not differ between Percoll and swim-up sperm separation methods (36.7 +/- 0.9% vs. 32.7 +/- 1.3%, p > 0.05). Furthermore, sperm capacitation by heparin alone or in combination with ionomycin did not lead to a significant increase in the normal fertilization rate (34.8 +/- 1.7 vs. 32.2 +/- 1.5%, respectively) in the oocytes of pubertal goats. In conclusion, the ovaries of pubertal black Bengal goats obtained from the slaughterhouse could be used for in vitro embryo production. However, further optimization of the IVM and IVF techniques are necessary for satisfactory in vitro embryo production.
Animals ; Culture Techniques ; Embryonic Development/*physiology ; Female ; Fertilization in Vitro/*veterinary ; Goats/*embryology ; Male ; Oocyte Retrieval/veterinary ; Oocytes/*physiology ; Ovary/cytology ; Sexual Maturation ; Sperm Capacitation ; Tissue and Organ Harvesting/veterinary

AIMTo evaluate the effect of acute lead chloride exposure on testis and sperm parameters in mice.

METHODSPbCl2, 74 mg/kg, was daily administered to sexually mature male mice for 3 days and the effects on the testicular histology and ultrastructure as well as the motility and density of spermatozoa in cauda epididymis were observed. An additional group of mice were treated for 1-3 days and were allowed to recover for 32 days to determine the reversibility of lead-induced changes.

RESULTSThe testicular weight, seminiferous tubular diameter and sperm counts were significantly decreased following 3 days of PbCl2 treatment, but were unaffected by shorter-term exposures. The changes caused by lead are mostly reversible.

CONCLUSIONAcute lead chloride exposure injures the fertility parameters of male mice and the effects are partially reversible.

Animals ; Epididymis ; drug effects ; physiology ; Lead ; pharmacology ; Male ; Mice ; Microscopy, Electron ; Sexual Maturation ; Sperm Motility ; drug effects ; Spermatogenesis ; drug effects ; physiology ; Spermatozoa ; cytology ; drug effects ; ultrastructure

Objective: To explore the developmental characteristics of circadian rhythms in hypothalamus-pituitary-adrenal (HPA) axis during puberty. Methods: A total of 1 070 students from Grade 2-3 in 3 primary schools in Ma'anshan city, Anhui province, were selected for physical examination and circadian rhythm of HPA axis checked from 2015 to 2017. Saliva samples were collected at each of the following three time points: immediately upon wakening, 30 minutes after wakening and bedtime, with the index of circadian rhythm of HPA axis calculated, which including cortisol awake response (CAR), cortisol in puberty priming and diurnal cortisol slope (DCS). Testicular volume, palpation and visual inspection of breast development were used to assess the state of purbety development on boys and girls. Information on gender, date of birth, time to fall asleep, wake-up time and weekly physical activity were gathered through questionnaire survey. Non-parametric test was used to compare the differences of baseline, follow-up period and different adolescent developmental processes of each index on circadian rhythm of HPA axis. Results: During the period of follow-up program and comparing with the continuous undeveloped group, CAR and the changes of CAR showed significantly increase, both in the puberty priming group and continuous development group, with statistically significant differences (CAR: Z=8.551, 4.680, respectively; P<0.01; the changes of CAR: Z=4.079, 2.700, respectively, P<0.01). There were no significant differences noticed in CAR and the changes of CAR between puberty priming group or continuous development group. The area under the curve (AUC) of cortisol in puberty priming group was slightly higher than that in the persistent undeveloped group (Z=2.591, P=0.010). Both the changes of daily cortisol slope (DCS) in puberty priming group and continuing developed group decreased significantly, when comparing with those in continuous undeveloped group (Z=-2.450, Z=-2.151; all P<0.05). There was no significant difference noticed in the changes of cortisol in puberty priming and DCS between different puberty development stages (the changes of AUC: χ(2)=2.747, P=0.253; DCS: χ(2)=4.554, P=0.032). Conclusions: The indexes of circadian rhythm of HPA axis were associated with the development of puberty. Both the cortisol awakening response and the total amount of diurnal cortisol secretion showed an increase, along with the puberty development. The change of diurnal cortisol slope declined with the development of puberty.
Adolescent ; Area Under Curve ; Circadian Rhythm ; Female ; Humans ; Hydrocortisone ; Hypothalamo-Hypophyseal System ; Male ; Pituitary-Adrenal System ; Pregnancy ; Saliva ; Sexual Maturation/physiology* ; Surveys and Questionnaires ; Wakefulness

AIMTo investigate the stage-specific localization of metastasis-associated protein 1 (MTA1) during spermatogenesis in adult human and mouse testis.

METHODSThe immunolocalization of MTA1 was studied by immunohistochemistry and Western blot analysis. The distribution pattern of MTA1 in mouse testis was confirmed by using quantitative analysis of purified spermatogenic cells.

RESULTSThe specificity of polyclonal antibody was confirmed by Western blot analysis. MTA1 was found expressed in the nucleus of germ cells, except elongate spermatids, and in the cytoplasm of Sertoli cells; Leydig cells did not show any specific reactivity. MTA1 possessed different distribution patterns in the two species: in humans, the most intensive staining was found in the nucleus of round spermatids and of primary spermatocytes while in mice, the most intense MTA1 staining was in the nucleus of leptotene, zygotene and pachytene spermatocytes. In both species the staining exhibited a cyclic pattern.

CONCLUSIONThe present communication initially provides new evidence for the potential role of MTA1 in mature testis. In addition, its distinctive expression in germ cells suggests a regulatory role of the peptide during spermatogenesis.

Adult ; Animals ; Animals, Outbred Strains ; Blotting, Western ; Histone Deacetylases ; metabolism ; Humans ; Male ; Mice ; Mice, Inbred BALB C ; Repressor Proteins ; metabolism ; Sexual Maturation ; physiology ; Species Specificity ; Spermatogenesis ; physiology ; Testis ; cytology ; metabolism ; Transcription Factors ; metabolism

OBJECTIVETo investigate the effects of prepubertal exposure to diethylstilbestrol (DES) on the testicular development and function of Sprague-Dawley (SD) rats.

METHODSNinety 21-day-old male SD rats were randomly and equally divided into 4 experimental groups (Da, Db, Dc and Dd), which were injected with DES dissolved in corn oil at the dose of 0.01, 0.1, 1.0 and 10.0 microg/(kg x d) from postnatal day (PND) 22 to 35, and a control group (C), which received vehicle only. The testicular development of all the rats was observed, and their testes were harvested in the stages of late puberty (PND 50), sexual maturity (PND 64) and adulthood (PND 130) respectively to determine the weight and histological features of the testis and examine the quality of the sperm in the epididymal cauda of the PND 130 rats.

RESULTSThe testis descent in the C, Da, Db, Dc and Dd groups occurred on PND 26.17 +/- 1.94, 26.83 +/- 1.47, 28.68 +/- 1.03, 33.50 +/- 1.87 and 41.50 +/- 2.74 respectively, significantly delayed in the Db, Dc and Dd groups compared with the C group (P < 0.05 or P < 0.01). On PND 50, the unilateral testis weights in the C, Da, Db, Dc and Dd groups were (1.38 +/- 0.01) g, (1.38 +/- 0.12) g, (1.30 +/- 0.14) g, (0.86 +/- 0.18) g and (0.73 +/- 0.27) g respectively, significantly less in the Dc and Dd groups than in the C group (P < 0.01). Compared with the C group, there was a slight decrease in the number of the cells in the epithelia of a few seminiferous tubules in the Db group on PND 50, maldevelopment of seminiferous tubules, reduced cell number in seminiferous epithelia, blocked spermatogenesis and aplasia of Leydig cells in the Dc and Dd groups in a dose-dependent manner. On PND 64, the unilateral testis weights in the C, Da, Db, Dc and Dd groups were (1.60 +/- 0. 06) g, (1.62 +/- 0.11) g, (1.58 +/- 0.08) g, (1.47 +/- 0.10) g and (0.99 +/- 0.37) g respectively, significantly less in the Dc and Dd groups than in the C group (P < 0.05 or P < 0.01), and the histological alteration of the testis in the Dc and Dd groups was similar to or less than that on PND 50. On PND 130, no statistic difference was observed either in unilateral testis weight or in the histological features of the testis between any experimental group and the control (P > 0.05). The sperm concentration in the epididymal cauda in the C, Da, Db, Dc and Dd groups were (73.00 +/- 16.90) x 10(6)/ml, (68.00 +/- 19.67) x 10(6)/ml, (68.67 +/- 12.15) x 10(6)/ml, (35.17 +/- 15.64) x 10(6)/ml and (19.13 +/- 5.17) x 10(6)/ml, significantly lower in the Dc and Dd groups than in the C group (P < 0.01). There was a significant decrease in sperm motility in the Dd group (P < 0.01), the percentage of grade a sperm in the Db, Dc and Dd groups (P < 0.05) and the percentage of grade b sperm in the Dd group (P < 0.01).

CONCLUSIONPrepubertal exposure to low dose of DES (0.01 microg/[kg x d] x 14 d) does not significantly affect the testicular development and function of SD rats, while high dose (1.0-10.0 microg/[kg x d] x 14 d) has significant short- (PND 50 and 64) or long-term (PND 130) toxic effect, which increases with dose and decreases with age. The mechanism of the toxic effect involves the insults to the development and function of Leydig and Sertoli cells.

Animals ; Carcinogens ; toxicity ; Diethylstilbestrol ; toxicity ; Dose-Response Relationship, Drug ; Male ; Organ Size ; drug effects ; Rats ; Rats, Sprague-Dawley ; Sexual Maturation ; drug effects ; Testis ; drug effects ; growth & development ; physiology ; Time Factors