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Nutrients Jan 2021Puberty is a crucial developmental stage in the life span, necessary to achieve reproductive and somatic maturity. Timing of puberty is modulated by and responds to... (Review)
Review
Puberty is a crucial developmental stage in the life span, necessary to achieve reproductive and somatic maturity. Timing of puberty is modulated by and responds to central neurotransmitters, hormones, and environmental factors leading to hypothalamic-pituitary-gonadal axis maturation. The connection between hormones and nutrition during critical periods of growth, like fetal life or infancy, is fundamental for metabolic adaptation response and pubertal development control and prediction. Since birth weight is an important indicator of growth estimation during fetal life, restricted prenatal growth, such as intrauterine growth restriction (IUGR) and small for gestational age (SGA), may impact endocrine system, affecting pubertal development. Successively, lactation along with early life optimal nutrition during infancy and childhood may be important in order to set up timing of sexual maturation and provide successful reproduction at a later time. Sexual maturation and healthy growth are also influenced by nutrition requirements and diet composition. Early nutritional surveillance and monitoring of pubertal development is recommended in all children, particularly in those at risk, such as the ones born SGA and/or IUGR, as well as in the case of sudden weight gain during infancy. Adequate macro and micronutrient intake is essential for healthy growth and sexual maturity.
Topics: Child; Child Nutritional Physiological Phenomena; Fetus; Humans; Infant; Nutritional Status; Puberty; Sexual Maturation; Time Factors
PubMed: 33525559
DOI: 10.3390/nu13020419 -
Experientia Oct 1991Two physiological components of sexual maturation, vaginal opening and first estrus, apparently evolve similarly in Wistar and Sprague-Dawley rats. However, a bimodal... (Review)
Review
Two physiological components of sexual maturation, vaginal opening and first estrus, apparently evolve similarly in Wistar and Sprague-Dawley rats. However, a bimodal distribution in the frequency of the days of vaginal opening is observed within a given strain, which is less related to heredity than to the timing and type of experiment. In addition, when the modulators of sexual maturation are reviewed, it can be observed that sensitivity to external stimuli can vary even within a strain. For a defined set of breeding conditions, one group of rats can be more susceptible to changes in the lighting regimen and not be affected by controlled stressors, while another group responds more to stress and less to light. The reason for susceptibility to one rather than another environmental factor under similar breeding conditions is not understood. In that context, it is difficult to evaluate the role of heredity when we cannot understand the full impact of the environment, not to mention maternal influence in fetal and early life. Using two lines of psychogenetically selected rats, it was possible to show that they had differences in sexual maturation, which strongly suggested a genetic predisposition. Nevertheless, the question arises as to whether the genetic locus directly affects organs implicated in sexual maturation or whether it acts on some unknown factor which only secondarily modifies sexual maturation. In summary, there is more need to understand the role of the environment, including that of the mother early in fetal and neonatal life. It is suggested that the mechanisms underlying organ growth are set for a given species, while developmental and environmental factors fix the timing of vaginal opening and first ovulation. In the rat, there appear to be two times which are preferred for vaginal opening, given the laboratory conditions that have been used in the last 20 or so years: an early period, at 31-35 days, and a late period, at 36-40 days. An explanation for this dichotomy would be that a combination of parameters (not necessarily always the same) is needed for vaginal opening. These parameters oscillate during sexual maturation with different frequencies, which can achieve resonance to lead to vaginal opening and ovulation only during given periods.
Topics: Aging; Animals; Environment; Female; Hormones; Rats; Rats, Inbred Strains; Reproduction; Sexual Maturation
PubMed: 1936201
DOI: 10.1007/BF01923338 -
Ciencia & Saude Coletiva Sep 2022This study aimed to investigate the relationship between sexual maturation and anthropometric and blood pressure indicators in teenagers. This was a population-based...
This study aimed to investigate the relationship between sexual maturation and anthropometric and blood pressure indicators in teenagers. This was a population-based cross-sectional study, conducted with 345 teenagers, aged 10 to 19 years, between 2018 and 2020. In this study, data referent to sociodemographic and anthropometric variables, blood pressure, and sexual maturation were collected. The data analysis was performed by applying the Principle Component Analysis (PCA), which generated three components and then tested the correlation between sexual maturation and the generated components. Most of the teenagers were female (53%), normotensive (66.1%), and with a normal weight (73%). A positive correlation was found between breast development and component 1 and component 2, as well as a negative correlation between the breasts and component 3. In the boys, the development of genitals and pubic hair was positively correlated with component 2 and inversely correlated with component 3. It could therefore be concluded that there is a relationship between sexual maturation and the anthropometric and blood pressure indicators, which proved to be representative variables for cardiovascular risk in teenagers, even if not in their entirety.
Topics: Adolescent; Anthropometry; Blood Pressure; Cross-Sectional Studies; Female; Humans; Male; Sexual Maturation
PubMed: 36000648
DOI: 10.1590/1413-81232022279.04622022 -
Anthropologischer Anzeiger; Bericht... 2015The inequalities among the socioeconomic strata in the Hungarian society increased during the last decades. Since the socioeconomic conditions play a decisive part in...
The inequalities among the socioeconomic strata in the Hungarian society increased during the last decades. Since the socioeconomic conditions play a decisive part in shaping the growth and maturation of children, our purpose was to study the body structure and the growth and maturation pattern of children living in deprived regions in Hungary. Our former analysis revealed that the prevalence of non-normal nutritional status was significantly higher in children and adolescents living in the seriously deprived regions of Hungary than the national reference values. The main purpose of the present study was to compare the sexual maturation pattern of pubertal children living in the deprived regions by comparing the timing of pubertal maturation events to the national reference values. Sexual maturity status of 711 girls and 790 boys (aged 10 - 16 years) living in the deprived small regions of Hungary was compared to the national reference values (Hungarian National Growth Study II). Sexual maturity status was estimated by the stages of pubic hair, axillary hair, breast and external genitalia development, as well as by the menarcheal and spermarcheal status, respectively. The median ages of being in the pubertal stages of the sexual characteristics, menarcheal and spermarcheal age were estimated by probit analysis. By comparing it to the national reference values, the timing of pubertal development in boys and girls living in the seriously deprived regions showed a 1 - 3-month shift toward older ages. However, the length of sexual maturation: the interval between the median ages of the first and last pubertal stages of sexual characteristics was similar in the subjects living in the regions of Hungary as the Hungarian reference values.
Topics: Adolescent; Anthropology, Physical; Child; Female; Humans; Hungary; Male; Menarche; Poverty; Puberty; Sex Characteristics; Sexual Maturation; Socioeconomic Factors
PubMed: 25779872
DOI: 10.1127/anthranz/2014/0435 -
Molecular Ecology Sep 2021Sexual maturation timing is a life-history trait central to the balance between mortality and reproduction. Maturation may be triggered when an underlying compound...
Sexual maturation timing is a life-history trait central to the balance between mortality and reproduction. Maturation may be triggered when an underlying compound trait, called liability, exceeds a threshold. In many different species and especially fishes, this liability is approximated by growth and body condition. However, environmental vs. genetic contributions either directly or via growth and body condition to maturation timing remain unclear. Uncertainty exists also because the maturation process can reverse this causality and itself affect growth and body condition. In addition, disentangling the contributions of polygenic and major loci can be important. In many fishes, males mature before females, enabling the study of associations between male maturation and maturation-unbiased female liability traits. Using 40 Atlantic salmon families, longitudinal common-garden experimentation, and quantitative genetic analyses, we disentangled environmental from polygenic and major locus (vgll3) effects on male maturation, and sex-specific growth and condition. We detected polygenic heritabilities for maturation, growth, and body condition, and vgll3 effects on maturation and body condition but not on growth. Longitudinal patterns for sex-specific phenotypic liability, and for genetic variances and correlations between sexes suggested that early growth and condition indeed positively affected maturation initiation. However, towards spawning time, causality appeared reversed for males whereby maturation affected growth negatively and condition positively via both the environmental and genetic effects. Altogether, the results indicate that growth and condition are useful traits to study liability for maturation initiation, but only until maturation alters their expression, and that vgll3 contributes to maturation initiation via condition.
Topics: Animals; Female; Humans; Life History Traits; Male; Phenotype; Reproduction; Salmo salar; Sexual Maturation; Transcription Factors
PubMed: 34228841
DOI: 10.1111/mec.16062 -
Hormone Research 1999Leptin, the ob gene product, is involved in the regulation of body weight in rodents, primates and humans. It provides a molecular basis for the lipostatic theory of the... (Review)
Review
Leptin, the ob gene product, is involved in the regulation of body weight in rodents, primates and humans. It provides a molecular basis for the lipostatic theory of the regulation of energy balance. White adipose tissue and placenta are the main sites of leptin synthesis. There is also evidence of ob gene expression in brown fat. Leptin seems to play a key role in the control of body fat stores by coordinated regulation of feeding behaviour, metabolic rate, autonomic nervous system regulation and body energy balance. Apart from the function of leptin in the central nervous system on the regulation of energy balance, it may well be one of the hormonal factors that signal to the brain the body's readiness for sexual maturation and reproduction. During late pregnancy and at birth when maternal fat stores have been developed, leptin levels are high. During these developmental stages leptin could be a messenger molecule signalling the adequacy of the fat stores for reproduction and maintenance of pregnancy. At later stages of gestation leptin could signal the expansion of fat stores in order to prepare the expectant mother for the energy requirements of full-term gestation, labour and lactation. Leptin serum concentrations change during pubertal development in rodents, primates and humans. In girls, leptin serum concentrations increase dramatically as pubertal development proceeds. The pubertal rise in leptin levels parallels the increase in body fat mass. In contrast, leptin levels increase shortly before and during the early stages of puberty in boys and decline thereafter. Testosterone has been found to suppress leptin synthesis by adipocytes both in vivo and in vitro. The decline of leptin levels in late puberty in boys accompanies increased androgen production during that time and most likely reflects suppression of leptin by testosterone and a decrease in fat mass and relative increase in muscle mass during late puberty in males. This overview focuses on those topics of leptin research which are of particular interest in reproductive and adolescent medicine.
Topics: Animals; Feeding and Eating Disorders; Female; Humans; Leptin; Male; Menstrual Cycle; Pregnancy; Puberty; Reproduction; Sexual Maturation
PubMed: 10592445
DOI: 10.1159/000053163 -
Scientific Reports Jan 2021In 2012, after the accident at the Fukushima Daiichi Nuclear Power Plant (FDNPP) that followed the Tohoku earthquake and tsunami in March 2011, no rock shell (Thais...
In 2012, after the accident at the Fukushima Daiichi Nuclear Power Plant (FDNPP) that followed the Tohoku earthquake and tsunami in March 2011, no rock shell (Thais clavigera; currently recognized as Reishia clavigera; Gastropoda, Neogastropoda, Muricidae) specimens were found near the plant from Hirono to Futaba Beach (a distance of approximately 30 km). In July 2016, however, rock shells were again found to inhabit the area. From April 2017 to May 2019, we collected rock shell specimens monthly at two sites near the FDNPP (Okuma and Tomioka) and at a reference site ~ 120 km south of the FDNPP (Hiraiso). We examined the gonads of the specimens histologically to evaluate their reproductive cycle and sexual maturation. The gonads of the rock shells collected at Okuma, ~ 1 km south of the FDNPP, exhibited consecutive sexual maturation during the 2 years from April 2017 to May 2019, whereas sexual maturation of the gonads of specimens collected at Hiraiso was observed only in summer. The consecutive sexual maturation of the gonads of the specimens collected at Okuma might not represent a temporary phenomenon but rather a site-specific phenotype, possibly caused by specific environmental factors near the FDNPP.
Topics: Animals; Ecosystem; Fukushima Nuclear Accident; Gastropoda; Gonads; Reproduction; Sexual Maturation; Time Factors
PubMed: 33436968
DOI: 10.1038/s41598-020-80686-3 -
Pediatric Endocrinology Reviews : PER Sep 2016Sexual maturity rating (SMR) is important in population studies and in clinical care. Pubertal staging allows doctors to assess the maturation of adolescents to... (Review)
Review
Sexual maturity rating (SMR) is important in population studies and in clinical care. Pubertal staging allows doctors to assess the maturation of adolescents to correlate several pubertal phenomena such as age at menarche, growth spurt and final height, to advise and manage patients appropriately and to have sensitive "sensors" of the effects of environmental exposure on human populations. The commonly used markers of the timing of female puberty are thelarche and menarche. Appearance of the breast bud is the first indicator of puberty onset in 90% of girls. Assessment of thelarche may be performed by a physician with expertise in adolescents or by self-assessment, in which the adolescent identifies her stage of maturation based on Tanner's photographs/illustrations. The assessment of Tanner stages by professionals provides more reliable information than self-assessment but may involve variations between observers. Tanner self-assessment has been proposed as an alternative in various studies. Some studies have found reasonable agreement between self-assessment and examination by a physician whereas others found discrepancies. Measuring nipple and areola diameters is feasible for sexual maturation staging. Both sizes show a significant increase during pubertal development and after menarche. However, the ratings using nipple/areola method need to be analyzed to establish their degree of concordance with standard techniques and other markers of development in girls.
Topics: Adolescent; Child; Diagnostic Techniques, Endocrine; Female; Humans; Menarche; Puberty; Self-Assessment; Sexual Development; Sexual Maturation
PubMed: 28508614
DOI: 10.17458/PER.2016.SESEEM.MethodsforRating -
American Journal of Primatology Oct 2015The life history of mammals underlies a fast-slow continuum, ranging from "slow" species with large body size, delayed sexual maturation, low fertility, and long...
The life history of mammals underlies a fast-slow continuum, ranging from "slow" species with large body size, delayed sexual maturation, low fertility, and long lifespan, to "fast" species showing the opposite traits. Primates fall into the "slow" category, considering their relatively low offspring numbers and delayed juvenile development. However, social and sexual maturation processes do not necessarily have to be completed simultaneously. The comparison of the timeframes for sexual and social maturation is largely lacking for primates, with the prominent exception of humans. Here, we compare both maturation processes in a basal primate, the gray mouse lemur, which ranges in many aspects at the fast end of the slow-fast life history continuum among primates. We compared the patterns and frequencies of various social and solitary behaviors in young adults (YA, 12-13 months old) and older individuals (A, ≥2 years) of both sexes outside estrus. Observations were conducted during mix-sexed dyadic encounter experiments under controlled captive conditions (eight dyads per age class). Results indicate that although all young adults were sexually mature, social maturation was not yet completed in all behavioral domains: Age-dependent differences were found in the number of playing dyads, female marking behavior, female aggression, and social tolerance. Thus, this study provides a first indication that social maturation lags behind sexual maturation in an ancestral nocturnal primate model, indicating that these two developmental schemes may have been decoupled early and throughout the primate lineage.
Topics: Age Factors; Aggression; Animals; Cheirogaleidae; Female; Male; Sexual Behavior, Animal; Sexual Maturation; Social Behavior
PubMed: 26119105
DOI: 10.1002/ajp.22440 -
Toxicology Sep 2013Endocrine disruptors (EDs) are exogenous substances or xenoestrogens natural or synthetic, capable of interacting with different systems and altering their normal... (Review)
Review
Evidence of reproductive disruption associated with neuroendocrine changes induced by UV-B filters, phthalates and nonylphenol during sexual maturation in rats of both gender.
Endocrine disruptors (EDs) are exogenous substances or xenoestrogens natural or synthetic, capable of interacting with different systems and altering their normal hormonal regulation, being the reproductive system one of the most affected. EDs produce their effects not only by acting on nuclear steroid receptors, but also on membrane receptors, steroidal and non-steroidal synthetic enzymatic pathways and/or metabolism. The incorporation to the body depend on each EDs, which are liposoluble and easily deposited in the tissue; thus ensuring a prolonged accumulation and release, even when the exposure is not continuous. In addition to cross the placenta, EDs may act in the offspring during the reproductive system formation and maturation key stages and its regulatory mechanisms. The effects of EDs can be multiple, but most acts mediating estrogenic and/or antiandrogenic effect. Three groups of EDs are widely used: in plastics (phtalates), sunscreens (cinnamate and methylbenzylcamphor), and detergents (nonylphenol). In this paper we review the effects of the exposure to these environmental chemicals on the reproductive system and the possible mechanisms by which they occur, focusing in the hypothalamic-pituitary neuroendocrine mechanisms that regulate the reproductive system.
Topics: Animals; Endocrine Disruptors; Female; Humans; Male; Neurosecretory Systems; Phenols; Phthalic Acids; Rats; Sexual Maturation; Sunscreening Agents
PubMed: 23778080
DOI: 10.1016/j.tox.2013.05.014