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Journal of Physiological Anthropology Feb 2023Human reproduction is energetically costly, even more so than other primates. In this review, we consider how the energy cost of physical activity impacts reproductive... (Review)
Review
Human reproduction is energetically costly, even more so than other primates. In this review, we consider how the energy cost of physical activity impacts reproductive tasks. Daily energy expenditure appears to be constrained, leading to trade-offs between activity and reproduction expenditures in physically active populations. High workloads can lead to suppression of basal metabolic rate and low gestational weight gain during pregnancy and longer interbirth intervals. These responses lead to variation in fertility, including age at first reproduction and interbirth interval. The influence of energetics is evident even in industrialized populations, where cultural and economic factors predominate. With the decoupling of skills acquisition from food procurement, extrasomatic resources and investment in individual offspring becomes very costly. The result is greater investment in fewer offspring. We present a summary of age at first reproduction and interbirth interval trends across a diverse, global sample representing 44 countries and two natural fertility populations. While economic factors impact fertility, women in energy-rich, industrialized populations are capable of greater reproductive output than women in energy-stressed populations. Thus, energetic factors can be disentangled from cultural and economic impacts on fertility. Future research should focus on objective measurements of energy intake, energy expenditure, and physical activity in a broader sample of populations to elucidate the role of energetics in shaping reproductive outcomes and health.
Topics: Pregnancy; Animals; Humans; Female; Fertility; Reproduction; Exercise
PubMed: 36829218
DOI: 10.1186/s40101-023-00318-3 -
Human Reproduction Update 2016The transmembrane ATP-binding cassette (ABC) transporters actively efflux an array of clinically relevant compounds across biological barriers, and modulate... (Review)
Review
BACKGROUND
The transmembrane ATP-binding cassette (ABC) transporters actively efflux an array of clinically relevant compounds across biological barriers, and modulate biodistribution of many physiological and pharmacological factors. To date, over 48 ABC transporters have been identified and shown to be directly and indirectly involved in peri-implantation events and fetal/placental development. They efflux cholesterol, steroid hormones, vitamins, cytokines, chemokines, prostaglandins, diverse xenobiotics and environmental toxins, playing a critical role in regulating drug disposition, immunological responses and lipid trafficking, as well as preventing fetal accumulation of drugs and environmental toxins.
METHODS
This review examines ABC transporters as important mediators of placental barrier functions and key reproductive processes. Expression, localization and function of all identified ABC transporters were systematically reviewed using PubMed and Google Scholar websites to identify relevant studies examining ABC transporters in reproductive tissues in physiological and pathophysiological states. Only reports written in English were incorporated with no restriction on year of publication. While a major focus has been placed on the human, extensive evidence from animal studies is utilized to describe current understanding of the regulation and function of ABC transporters relevant to human reproduction.
RESULTS
ABC transporters are modulators of steroidogenesis, fertilization, implantation, nutrient transport and immunological responses, and function as 'gatekeepers' at various barrier sites (i.e. blood-testes barrier and placenta) against potentially harmful xenobiotic factors, including drugs and environmental toxins. These roles appear to be species dependent and change as a function of gestation and development. The best-described ABC transporters in reproductive tissues (primarily in the placenta) are the multidrug transporters p-glycoprotein and breast cancer-related protein, the multidrug resistance proteins 1 through 5 and the cholesterol transporters ABCA1 and ABCG1.
CONCLUSIONS
The ABC transporters have various roles across multiple reproductive tissues. Knowledge of efflux direction, tissue distribution, substrate specificity and regulation of the ABC transporters in the placenta and other reproductive tissues is rapidly expanding. This will allow better understanding of the disposition of specific substrates within reproductive tissues, and facilitate development of novel treatments for reproductive disorders as well as improved approaches to protecting the developing fetus.
Topics: ATP-Binding Cassette Transporters; Animals; Blastocyst; Embryonic Development; Female; Humans; Placenta; Pregnancy; Reproduction; Tissue Distribution
PubMed: 26545808
DOI: 10.1093/humupd/dmv049 -
Journal of Assisted Reproduction and... Dec 2018Common human reproductive inefficiencies have multiple etiologies. Going against chance, many effects, such as polycystic ovaries, endometriosis, and folate metabolic... (Review)
Review
Common human reproductive inefficiencies have multiple etiologies. Going against chance, many effects, such as polycystic ovaries, endometriosis, and folate metabolic issues, have genetic components, while aneuploid losses arise from diverse mitotic and meiotic errors at different stages, some transitory. This can be advantageous, since greater overall survival with fewer offspring can increase reproductive success. Benefits primarily accrue to mothers, who bear most child related costs, and for whom early losses are less costly than late. Different adaptations to different situations reflect human evolutionary history. For early speciation, periodic climate extremes repeatedly reduced resources, favoring limitations while contracted populations helped fix relevant genes. Later, under better conditions, evolving social cooperation could increase fecundity faster than it added resources, further supporting reproductive suppression through mitotic aneuploidy, with very early losses minimizing maternal costs. The grandmother hypothesis suggests benefits in limiting reproduction as maternal age increased pregnancy risks in order to support grandchildren as they arrived, selecting for maternal age-related meiotic aneuploidy. Finally, with variable short-term agricultural shortages, acute reproductive responses arose through chromatin "nutrient sensor"-regulated epigenetic effects that also shifted some lethal effects earlier, reducing both maternal and mutation load costs. Overall, despite suggestions to the contrary, it is likely that human selective pressures have not decreased with civilization, but that many of the costs have been shifted to early reproduction.
Topics: Aneuploidy; Female; Fertility; Humans; Maternal Age; Pregnancy; Reproduction
PubMed: 30116921
DOI: 10.1007/s10815-018-1285-3 -
Cell Reports. Medicine Sep 2020The melding of human genetics with clinical assisted reproduction, now all but self-evident, gave flight to diagnostic and therapeutic approaches previously deemed... (Review)
Review
The melding of human genetics with clinical assisted reproduction, now all but self-evident, gave flight to diagnostic and therapeutic approaches previously deemed infeasible. Preimplantation genetic diagnosis, mitochondrial replacement techniques, and remedial germline editing are particularly noteworthy. Here we explore the relevant disruption brought forth by coalescence of these mutually enabling disciplines with the regulatory and legal implications thereof.
Topics: Female; Gene Editing; Genetics, Medical; Germ Cells; Human Genetics; Humans; Pregnancy; Preimplantation Diagnosis; Reproduction; Reproductive Techniques, Assisted
PubMed: 33205071
DOI: 10.1016/j.xcrm.2020.100093 -
Fertility and Sterility Dec 1992To relay the current knowledge on the interaction between the immune and reproductive systems that results from sharing certain lymphohematopoietic cytokines and their... (Review)
Review
OBJECTIVE
To relay the current knowledge on the interaction between the immune and reproductive systems that results from sharing certain lymphohematopoietic cytokines and their receptors.
DATA IDENTIFICATION
Major studies related to this topic have been identified through MEDLINE searches and through the published literature.
STUDY SELECTION
Those that have reported on the role of cytokines in the neuroendocrine events of reproduction, ovarian function, placenta, and the developing embryo.
RESULTS
The field of growth factor and cytokines and their effects on reproduction is a rapidly growing new area of investigation. Immune cells and related cytokines have been shown to affect the neuroendocrine events of reproduction, ovarian function, placenta, and the developing embryo. Furthermore, it is now becoming apparent that these relationships are reciprocal in that the different cellular components of the neuroendocrine and reproductive systems and the developing embryo can modulate the production of cytokine by the immune system and can also produce certain cytokines. The presence of lymphocytes and macrophages in the female reproductive system, together with the fact that these cells may secrete soluble factors influencing embryo development and trophoblast growth, might suggest that cytokines may play a fundamental role in the mechanisms of immunological reproductive failure. In addition, different mixtures of these mediators, generated by immune cells, the developing embryo, or other maternal cells, may modulate the fine tuning of these activities.
CONCLUSIONS
Current knowledge indicates a close interaction between the immune and reproductive functions. Further understanding of these interactions may lead to new concepts in fertility regulation.
Topics: Animals; Cytokines; Embryonic and Fetal Development; Female; Humans; Hypothalamic Hormones; Ovary; Pituitary Hormones; Placenta; Pregnancy; Reproduction
PubMed: 1459253
DOI: 10.1016/s0015-0282(16)55548-4 -
General and Comparative Endocrinology Nov 2016Dr. Louis J. Guillette Jr. thought of himself as a reproductive biologist. However, his interest in reproductive biology transcended organ systems, life history stages,... (Comparative Study)
Comparative Study Review
Dr. Louis J. Guillette Jr. thought of himself as a reproductive biologist. However, his interest in reproductive biology transcended organ systems, life history stages, species, and environmental contexts. His integrative and collaborative nature led to diverse and fascinating research projects conducted all over the world. He doesn't leave us with a single legacy. Instead, he entrusts us with several. The purpose of this review is to highlight those legacies, in both breadth and diversity, and to illustrate Dr. Guillette's grand contributions to the field of reproductive biology. He has challenged the field to reconsider how we think about our data, championed development of novel and innovative techniques to measure endocrine function, helped define the field of endocrine disruption, and lead projects to characterize new endocrine disrupting chemicals. He significantly influenced our understanding of evolution, and took bold and important steps to translate all that he has learned into advances in human reproductive health. We hope that after reading this manuscript our audience will appreciate and continue Dr. Guillette's practice of open-minded and passionate collaboration to understand the basic mechanisms driving reproductive physiology and to ultimately apply those findings to protect and improve wildlife and human health.
Topics: Alligators and Crocodiles; Animals; Biological Evolution; Endocrine Disruptors; Reproduction; Translational Research, Biomedical; Xenobiotics
PubMed: 27013381
DOI: 10.1016/j.ygcen.2016.03.026 -
Frontiers in Neuroendocrinology Apr 2015Animals inhabiting temperate and boreal latitudes experience marked seasonal changes in the quality of their environments and maximize reproductive success by phasing... (Review)
Review
Animals inhabiting temperate and boreal latitudes experience marked seasonal changes in the quality of their environments and maximize reproductive success by phasing breeding activities with the most favorable time of year. Whereas the specific mechanisms driving seasonal changes in reproductive function vary across species, converging lines of evidence suggest gonadotropin-inhibitory hormone (GnIH) serves as a key component of the neuroendocrine circuitry driving seasonal changes in reproduction and sexual motivation in some species. In addition to anticipating environmental change through transduction of photoperiodic information and modifying reproductive state accordingly, GnIH is also positioned to regulate acute changes in reproductive status should unpredictable conditions manifest throughout the year. The present overview summarizes the role of GnIH in avian and mammalian seasonal breeding while considering the similarities and disparities that have emerged from broad investigations across reproductively photoperiodic species.
Topics: Animals; Birds; Hypothalamic Hormones; Kisspeptins; Mammals; Reproduction; Seasons
PubMed: 25511257
DOI: 10.1016/j.yfrne.2014.12.001 -
Cadernos de Saude Publica 2022This article aims to discuss the use of Social Reproduction, proposed by Juan Samaja, in the analysis of living and health conditions in a context of an sustanaible...
This article aims to discuss the use of Social Reproduction, proposed by Juan Samaja, in the analysis of living and health conditions in a context of an sustanaible development reserve in the Brazilian Amazon. This study uses a comprehensive approach to Social Reproduction processes that comprise the network of hierarchically organized structures using the analysis of social interactions of narrated and observable events, applied to the data matrix. The Ecological Reproduction of life in the riverside forest is negatively expressed in bio-communal life, as the strategic actions provided by the Political, Economic and Cultural Reproductions, that is, the environmental policy actions, do not value the local way of life. The deficient access to social goods and services, including health care, from the Political and Techno-Economic Reproductions, has an impact on the material basis of the Bio-Communal Reproduction, whose outcome is high frequency of disease complaints and workplace accidents, such as infectious gastroenteritis, malaria, tuberculosis, leprosy, and poisoning by venomous animals. Ensuring access to social goods and services, in particular health care, is essential for improving resilience to the forest adversities. In conclusion, the social reproduction data matrix helped understand the processes of Social Reproduction that are part of the hierarchically organized structures, whose interactions shaped the living and health conditions of the riverside population analyzed in this study.
Topics: Animals; Brazil; Reproduction; Health Facilities; Accidents, Occupational; Environmental Policy
PubMed: 36449849
DOI: 10.1590/0102-311XPT150320 -
Journal of Dairy Science Apr 2017Objectives were to evaluate associations among gestation length (GL) and performance in Holstein cows and their offspring. A total of 8,095 Holstein cows and 3,635...
Objectives were to evaluate associations among gestation length (GL) and performance in Holstein cows and their offspring. A total of 8,095 Holstein cows and 3,635 female offspring born alive on 2 farms using only artificial insemination (AI) were evaluated. Gestation length averaged 276 ± 6 d in the 8,095 dams, and it was categorized as short (SGL; at least 1 SD below the population mean; mean = 266 d, range 256 to 269 d), average (AGL; population mean ± 1 SD; mean = 276 d, range 270 to 282 d), or long (LGL; at least 1 SD above the population mean; mean = 285 d, range 283 to 296 d). Responses evaluated in dams included incidence of diseases within 90 d in milk (DIM), pregnancy at first AI and by 300 DIM, and time to pregnancy. Milk yield and removal from the herd by culling or death were recorded for the first 300 DIM. Responses evaluated in female offspring born alive included removal from the herd and reproductive performance. Within primiparous cows, those with SGL had greater incidence of stillbirth, retained placenta, and metritis than primiparous with AGL or LGL; however, within multiparous cows, those with SGL or LGL had greater incidence of dystocia, stillbirth, retained placenta, and metritis than cows with AGL. Morbidity and rate of morbidity were greater for SGL and LGL than AGL. Rate of removal of dams from the herd was 38% faster for SGL than AGL. Milk production was greatest in AGL cows, but responses depended on parity. For primiparous cows, milk production was less in SGL and LGL than in AGL (AGL = 35.4, SGL = 34.6, LGL = 33.0 ± 0.4 kg/d), whereas for multiparous cows, production was less in SGL but greater in LGL than in AGL (AGL = 41.6, SGL = 38.6, LGL = 42.4 ± 0.3 kg/d). A smaller proportion of cows with SGL received at least one AI, but pregnancy at first AI did not differ among groups. Rate of pregnancy was 11% slower for LGL multiparous than for AGL multiparous. By 300 DIM, pregnancy was greater in AGL than SGL. Pregnancy by 300 DIM in multiparous cows was also greater for AGL than LGL. Heifers from dams with GL that deviated from AGL had greater mortality postweaning (AGL = 3.2 vs. SGL = 6.5 vs. LGL = 5.4%). The rate of removal from the herd was greater for SGL (adjusted hazard ratio = 1.78; 95% CI: 1.26 to 2.52) and LGL (adjusted hazard ratio = 2.00; 95% CI: 1.45 to 2.76) than for AGL heifers. Pregnancy at first AI was lowest for LGL and by 500 d of age a larger proportion of AGL heifers were pregnant than LGL (AGL = 82.3 vs. SGL = 79.2 vs. LGL = 74.0%). Cows with GL within 1 SD of the population mean (270 to 282 d) had improved health, production, and reproduction. Heifers from cows with GL within 1 SD of the population mean had improved health and reproduction. Gestation length affects performance of both dams and their offspring.
Topics: Animals; Cattle; Female; Insemination, Artificial; Lactation; Milk; Parity; Pregnancy; Pregnancy, Animal; Reproduction
PubMed: 28161176
DOI: 10.3168/jds.2016-11867 -
Hormones and Behavior Jan 2016This article is part of a Special Issue "Parental Care". The reproductive experience of pregnancy, lactation and motherhood can significantly remodel the female's... (Review)
Review
This article is part of a Special Issue "Parental Care". The reproductive experience of pregnancy, lactation and motherhood can significantly remodel the female's biological state, affecting endocrine, neuroendocrine, neural, and immunological processes. The brain, pituitary gland, liver, thymus, and mammary tissue are among the structures that are modified by reproductive experience. The present review that focuses on rodent research, but also includes pertinent studies in sheep and other species, identifies specific changes in these processes brought about by the biological states of pregnancy, parturition, and lactation and how the components of reproductive experience contribute to the remodeling of the maternal brain and organ systems. Findings indicate that prior parity alters key circulating hormone levels and neural receptor gene expression. Moreover, reproductive experience results in modifications in neural processes and glial support. The possible role of pregnancy-induced neurogenesis is considered in the context of neuroplasticity and behavior, and the effects of reproductive experience on maternal memory, i.e. the retention of maternal behavior, together with anxiety and learning are presented. Together, these sets of findings support the concept that the neural and biological state of the adult female is significantly and dramatically altered on a long-term basis by the experiences of parity and motherhood. Remodeling of the maternal brain and other biological systems is posited to help facilitate adaptations to environmental/ecological challenges as the female raises young and ages.
Topics: Adaptation, Physiological; Animals; Brain; Female; Humans; Lactation; Maternal Behavior; Neurosecretory Systems; Parity; Parturition; Pregnancy; Reproduction; Sheep
PubMed: 26388065
DOI: 10.1016/j.yhbeh.2015.09.001