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1.
Chemosphere ; 260: 127542, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32683019

RESUMO

Bees are exposed to endocrine active insecticides. Here we assessed expressional alteration of marker genes indicative of endocrine effects in the brain of honey bees. We exposed foragers to chlorpyrifos, cypermethrin and thiacloprid and assessed the expression of genes after exposure for 24 h, 48 h and 72 h. Chlorpyrifos caused the strongest expressional changes at 24 h characterized by induction of vitellogenin, major royal jelly protein (mrjp) 2 and 3, insulin-like peptide (ilp1), alpha-glucosidase (hbg3) and sima, and down-regulation of buffy. Cypermethrin caused minor induction of mrjp1, mrjp2, mmp1 and ilp1. The sima transcript showed down-regulation at 48 h and up-regulation at 72 h. Exposure to thiacloprid caused down-regulation of vitellogenin, mrjp1 and sima at 24 h, and hbg3 at 72 h, as well as induction of ilp1 at 48 h. The buffy transcript was down-regulated at 24 h and up-regulated at 48 h. Despite compound-specific expression patterns, each insecticide altered the expression of some of the suggested endocrine system related genes. Our study suggests that expressional changes of genes prominently expressed in nurse or forager bees, including down-regulation of buffy and mrjps and up-regulation of hbg3 and ilp1 may serve as indicators for endocrine activity of insecticides in foragers.


Assuntos
Abelhas/fisiologia , Sistema Endócrino/fisiologia , Inseticidas/toxicidade , Animais , Encéfalo , Clorpirifos , Neonicotinoides , Piretrinas , Tiazinas , Transcrição Genética/efeitos dos fármacos , Vitelogeninas
2.
PLoS Genet ; 16(5): e1008361, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32463812

RESUMO

Osteocalcin (OCN), the most abundant noncollagenous protein in the bone matrix, is reported to be a bone-derived endocrine hormone with wide-ranging effects on many aspects of physiology, including glucose metabolism and male fertility. Many of these observations were made using an OCN-deficient mouse allele (Osc-) in which the 2 OCN-encoding genes in mice, Bglap and Bglap2, were deleted in ES cells by homologous recombination. Here we describe mice with a new Bglap and Bglap2 double-knockout (dko) allele (Bglap/2p.Pro25fs17Ter) that was generated by CRISPR/Cas9-mediated gene editing. Mice homozygous for this new allele do not express full-length Bglap or Bglap2 mRNA and have no immunodetectable OCN in their serum. FTIR imaging of cortical bone in these homozygous knockout animals finds alterations in the collagen maturity and carbonate to phosphate ratio in the cortical bone, compared with wild-type littermates. However, µCT and 3-point bending tests do not find differences from wild-type littermates with respect to bone mass and strength. In contrast to the previously reported OCN-deficient mice with the Osc-allele, serum glucose levels and male fertility in the OCN-deficient mice with the Bglap/2pPro25fs17Ter allele did not have significant differences from wild-type littermates. We cannot explain the absence of endocrine effects in mice with this new knockout allele. Possible explanations include the effects of each mutated allele on the transcription of neighboring genes, or differences in genetic background and environment. So that our findings can be confirmed and extended by other interested investigators, we are donating this new Bglap and Bglap2 double-knockout strain to the Jackson Laboratories for academic distribution.


Assuntos
Sistema Endócrino/fisiologia , Osteocalcina/genética , Animais , Densidade Óssea/genética , Osso e Ossos/metabolismo , Sistema Endócrino/metabolismo , Feminino , Fertilidade/genética , Resistência à Insulina/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Osteocalcina/deficiência
4.
PLoS One ; 15(1): e0227575, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31940330

RESUMO

The primeval function of the mammalian hippocampus (HPC) remains uncertain. Implicated in learning and memory, spatial navigation, and neuropsychological disorders, evolutionary theory suggests that the HPC evolved from a primeval chemosensory epithelium. Deficits in sensing of internal body status ('interoception') in patients with HPC lesions argue that internal sensing may be conserved in higher vertebrates. We studied the expression patterns in mouse brain of 250 endocrine receptors that respond to blood-borne ligands. Key findings are (i) the proportions and levels of endocrine receptor expression in the HPC are significantly higher than in all other comparable brain regions. (ii) Surprisingly, the distribution of endocrine receptor expression within mouse HPC was found to be highly structured: receptors signaling 'challenge' are segregated in dentate gyrus (DG), whereas those signaling 'sufficiency' are principally found in cornu ammonis (CA) regions. Selective expression of endocrine receptors in the HPC argues that interoception remains a core feature of hippocampal function. Further, we report that ligands of DG receptors predominantly inhibit both synaptic potentiation and neurogenesis, whereas CA receptor ligands conversely promote both synaptic potentiation and neurogenesis. These findings suggest that the hippocampus acts as an integrator of body status, extending its role in context-dependent memory encoding from 'where' and 'when' to 'how I feel'. Implications for anxiety and depression are discussed.


Assuntos
Giro Denteado/metabolismo , Sistema Endócrino/metabolismo , Regulação da Expressão Gênica , Hipocampo/metabolismo , Receptores de Superfície Celular/metabolismo , Animais , Sistema Endócrino/citologia , Sistema Endócrino/fisiologia , Hipocampo/citologia , Hipocampo/fisiologia , Humanos , Camundongos , Potenciais Sinápticos
5.
Gen Comp Endocrinol ; 287: 113342, 2020 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-31783025

RESUMO

Copper is a metal ion present in all organisms, where it has well-known roles in association with proteins and enzymes essential for cellular processes. In the early decades of the twentieth century copper was shown to influence mammalian reproductive biology, and it was subsequently shown to exert effects primarily at the level of the pituitary gland and/or hypothalamic regions of the brain. Furthermore, it has been reported that copper can interact with key neuropeptides in the hypothalamic-pituitary-gonadal axis, notably gonadotropin-releasing hormone (GnRH) and neurokinin B. Interestingly, recent phylogenetic analysis of the sequences of GnRH-related peptides indicates that copper binding is an evolutionarily ancient property of this neuropeptide family, which has been variously retained, modified or lost in the different taxa. In this mini-review the metal-binding properties of neuropeptides in the vertebrate reproductive pathway are reviewed and the evolutionary and functional significance of copper binding by GnRH-related neuropeptides in vertebrates and invertebrates are discussed.


Assuntos
Cobre/farmacologia , Sistema Endócrino/efeitos dos fármacos , Hormônio Liberador de Gonadotropina/efeitos dos fármacos , Neurocinina B/efeitos dos fármacos , Reprodução/efeitos dos fármacos , Animais , Sistema Endócrino/fisiologia , Hormônio Liberador de Gonadotropina/química , Hormônio Liberador de Gonadotropina/fisiologia , Invertebrados/metabolismo , Mamíferos/metabolismo , Neurocinina B/química , Neurocinina B/fisiologia , Conformação Proteica/efeitos dos fármacos , Reprodução/fisiologia , Relação Estrutura-Atividade , Vertebrados/metabolismo
6.
Am J Physiol Endocrinol Metab ; 318(2): E297-E309, 2020 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-31770013

RESUMO

As a model of extreme conditions, eight healthy women, part of a 40-member Nepal mountain-climbing expedition, were monitored for dynamic endocrine adaptations. Endocrine measurements were made at frequent intervals over a 6-10-h period at four altitudes: 450 m, 4,800 m (base camp), 6,050 m, and again at 4,800 m (on descent) after an acclimatization (A) period (4,800 mA). Quantified hormones were growth hormone (GH), prolactin (PROL), cortisol (Cort), thyroid-stimulating hormone (TSH), and free thyroxine. These hormones are important to the anabolic/catabolic balance of the body, and are vital to growth, homeostasis, hypothalamic inhibition, regulation of stress, and metabolism. A key secondary question was the degree to which acclimatization can stabilize hormonal disruption. On the basis of statistical false discovery rates, the present analyses unveil marked adaptive changes in the thyroid axis at the level of pulsatile secretion of the pituitary hormone TSH and its downstream product, free thyroxine; strong effects on the mass of GH, TSH, Cort, and PROL secretion per burst; and prominent pulsatile frequency disruption and recovery for PROL and Cort. Because pulsatility changes reflect de facto perturbations in hypothalamo-pituitary control mechanisms, the present data introduce the concept of both frequency- and amplitude-dependent adaptive control of brain-pituitary neuroendocrine signals under conditions of extreme altitude exertion and exposure.


Assuntos
Altitude , Sistema Endócrino/fisiologia , Aclimatação , Adaptação Fisiológica , Adulto , Feminino , Hormônio do Crescimento Humano/sangue , Humanos , Hidrocortisona/sangue , Sistema Hipotálamo-Hipofisário/metabolismo , Sistema Hipotálamo-Hipofisário/fisiologia , Hipóxia/metabolismo , Montanhismo , Sistema Hipófise-Suprarrenal/metabolismo , Sistema Hipófise-Suprarrenal/fisiologia , Prolactina/sangue , Hormônios Tireóideos/sangue
7.
Animal ; 14(4): 799-806, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31690360

RESUMO

Shearing during the latter half of pregnancy is a common practice to improve flock health and productivity. Previous studies have demonstrated that shearing pregnant ewes at mid or late pregnancy is associated with an increase in lamb birth weight. In the present study, we used singleton Polypay × Dorset pregnant sheep, to investigate the potential roles of placental function and changes in maternal metabolism in underlying this increased birth weight response. Two groups were randomly established and blocked at enrollment by animal BW, body condition score and subcutaneous adipose tissue depth. The groups were shorn (SH; n = 18) or not (C; n = 20) at gestational day (GD) 107 ± 1 (mean ± SEM). Weekly maternal plasma samples were collected between shearing and birth, but only six samples were assayed for progesterone, pregnancy-associated glycoproteins (PAG1), glucose and non-esterified fatty acids (NEFAs). At birth, sex, birth weight, and newborn body mass index (BMI) were recorded. Maternal BW during mid- to late-pregnancy was similar between groups. Shearing resulted in increased lamb birth weight and BMI (P < 0.05) regardless of fetal sex but did not affect the maternal concentration of PAG1 or progesterone from GDs 100 to 142. After shearing (GD100) and up to lambing, shorn females had higher circulating glucose concentrations (P < 0.05), but not NEFA, compared to the control group. Maternal circulating PAG1, progesterone, glucose or NEFA concentration across pregnancy did not differ according to lamb sex. Across pregnancy, birth weight was positively associated with PAG1 (P < 0.001), but not with progesterone concentrations. In conclusion, weight and BMI at birth were higher in both sexes upon shearing in singleton pregnancies. Despite PAG1 being associated with birth weight, late-pregnancy shearing did not alter the placental endocrine response. Whether other placental factors are altered upon shearing and may influence the increase in birth weight and BMI remain to be investigated.


Assuntos
Progesterona/sangue , Ovinos/fisiologia , Animais , Peso ao Nascer , Glicemia/análise , Sistema Endócrino/fisiologia , Ácidos Graxos não Esterificados/sangue , Feminino , Glicoproteínas/sangue , Masculino , Parto , Placenta/fisiologia , Gravidez , Lã/fisiologia
8.
Trends Endocrinol Metab ; 30(11): 793-806, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31668559

RESUMO

Endocrine system regulation is important for the maintenance of homeostasis; it controls hormonal functions in complex physiology and behavior and adaptations to social environments. Evidence indicates that for more than 35 000 years, dogs (Canis familiaris) have been domesticated through living with humans. For example, they have acquired human-like social skills, such as eye gazing and pointing gestures. These unique behaviors are, at least partially, regulated by hormones and are thought to have been genetically altered throughout domestication. Glucocorticoids affect social tolerance, while oxytocin facilitates social coordination and familiarity between individuals. We review historical and recent literature to facilitate an understanding of the roles of glucocorticoid and oxytocin functions in the human-canine coexistence dynamic established during domestication.


Assuntos
Sistema Endócrino/metabolismo , Sistema Endócrino/fisiologia , Animais , Comportamento Animal , Coevolução Biológica , Cães , Domesticação , Glucocorticoides/metabolismo , Humanos , Ocitocina/metabolismo
9.
Development ; 146(21)2019 11 04.
Artigo em Inglês | MEDLINE | ID: mdl-31597660

RESUMO

Retinoic acid (RA) is crucial for mammalian spermatogonia differentiation, and stimulates Stra8 expression, a gene required for meiosis. Certain fish species, including zebrafish, have lost the stra8 gene. While RA still seems important for spermatogenesis in fish, it is not known which stage(s) respond to RA or whether its effects are integrated into the endocrine regulation of spermatogenesis. In zebrafish, RA promoted spermatogonia differentiation, supported androgen-stimulated meiosis, and reduced spermatocyte and spermatid apoptosis. Follicle-stimulating hormone (Fsh) stimulated RA production. Expressing a dominant-negative RA receptor variant in germ cells clearly disturbed spermatogenesis but meiosis and spermiogenesis still took place, although sperm quality was low in 6-month-old adults. This condition also activated Leydig cells. Three months later, spermatogenesis apparently had recovered, but doubling of testis weight demonstrated hypertrophy, apoptosis/DNA damage among spermatids was high and sperm quality remained low. We conclude that RA signaling is important for zebrafish spermatogenesis but is not of crucial relevance. As Fsh stimulates androgen and RA production, germ cell-mediated, RA-dependent reduction of Leydig cell activity may form a hitherto unknown intratesticular negative-feedback loop.


Assuntos
Androgênios/fisiologia , Sistema Endócrino/fisiologia , Hormônio Foliculoestimulante/fisiologia , Transdução de Sinais , Espermatogênese , Tretinoína/fisiologia , Animais , Bussulfano/química , Diferenciação Celular/genética , Retroalimentação Fisiológica , Regulação da Expressão Gênica no Desenvolvimento , Masculino , Camundongos , Retinoides/fisiologia , Espermátides/fisiologia , Espermatócitos/fisiologia , Espermatogônias/fisiologia , Testículo/fisiologia , Transgenes , Peixe-Zebra
10.
Acta Vet Scand ; 61(1): 46, 2019 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-31585551

RESUMO

Urocortins (Ucns), peptides belonging to the corticotropin-releasing hormone (CRH) family, are classified into Ucn1, Ucn2, and Ucn3. They are involved in regulating several body functions by binding to two G protein-coupled receptors: receptor type 1 (CRHR1) and type 2 (CRHR2). In this review, we provide a historical overview of research on Ucns and their receptors in the mammalian endocrine system. Although the literature on the topic is limited, we focused our attention particularly on the main role of Ucns and their receptors in regulating the hypothalamic-pituitary-adrenal and thyroid axes, reproductive organs, pancreas, gastrointestinal tract, and other tissues characterized by "diffuse" endocrine cells in mammals. The prominent function of these peptides in health conditions led us to also hypothesize an action of Ucn agonists/antagonists in stress and in various diseases with its critical consequences on behavior and physiology. The potential role of the urocortinergic system is an intriguing topic that deserves further in-depth investigations to develop novel strategies for preventing stress-related conditions and treating endocrine diseases.


Assuntos
Sistema Endócrino/fisiologia , Urocortinas/metabolismo , Animais , Doenças do Sistema Endócrino/fisiopatologia , Pesquisa/tendências , Estresse Fisiológico , Urocortinas/agonistas , Urocortinas/antagonistas & inibidores
11.
Am J Primatol ; 81(10-11): e23053, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31532020

RESUMO

Gut microbial communities communicate bidirectionally with the brain through endocrine, immune, and neural signaling, influencing the physiology and behavior of hosts. The emerging field of microbial endocrinology offers innovative perspectives and methods to analyze host-microbe relationships with relevance to primate ecology, evolution, and conservation. Herein we briefly summarize key findings from microbial endocrinology and explore how applications of a similar framework could inform our understanding of primate stress and reproductive physiology and behavior. We conclude with three guiding hypotheses to further investigate endocrine signaling between gut microbes and the host: (a) host-microbe communication systems promote microbe-mediated stability, in which the microbes are using endocrine signaling from the host to maintain a functioning habitat for their own fitness, (b) host-microbe communication systems promote host-mediated stability, in which the host uses the endocrine system to monitor microbial communities and alter these communities to maintain stability, or (c) host-microbe systems are simply the product of coincidental cross-talk between the host and microbes due to similar molecules from shared ancestry. Utilizing theory and methodology for studying relationships between the microbiome, hormones, and behavior of wild primates is an uncharted frontier with many promising insights when applied to primatology.


Assuntos
Sistema Endócrino/fisiologia , Microbioma Gastrointestinal/fisiologia , Primatas/microbiologia , Primatas/fisiologia , Animais , Comportamento Animal/fisiologia , Feminino , Microbioma Gastrointestinal/efeitos dos fármacos , Genitália/fisiologia , Hormônios/farmacologia , Masculino , Transdução de Sinais
12.
Brain Struct Funct ; 224(9): 3059-3073, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31493024

RESUMO

The development of individual organs and the whole organism is under the control by morphogenetic factors over the critical period of morphogenesis. This study was aimed to test our hypothesis that the developing brain operates as an endocrine organ during morphogenesis, in rats during the perinatal period (Ugrumov in Neuro Chem 35:837-850, 2010). Norepinephrine, which is a morphogenetic factor, was used as a marker of the endocrine activity of the developing brain, although it is also secreted by peripheral organs. In this study, it was first shown that the concentration of norepinephrine in the peripheral blood of neonatal rats is sufficient to ensure the morphogenetic effect on the peripheral organs and the brain itself. Using pharmacological suppression of norepinephrine production in the brain, but not in peripheral organs, it was shown that norepinephrine is delivered from the brain to the general circulation in neonatal rats, that is, during morphogenesis. In fact, even partial suppression of norepinephrine production in the brain of neonatal rats led to a significant decrease of norepinephrine concentration in plasma, suggesting that at this time the brain is an important source of circulating norepinephrine. Conversely, the suppression of the production of norepinephrine in the brain of prepubertal rats did not cause a change in its concentration in plasma, showing no secretion of brain-derived norepinephrine to the bloodstream after morphogenesis. The above data support our hypothesis that morphogenetic factors, including norepinephrine, are delivered from the developing brain to the bloodstream, which occurs only during the critical period of morphogenesis.


Assuntos
Encéfalo/crescimento & desenvolvimento , Morfogênese , Norepinefrina/fisiologia , Animais , Sistema Endócrino/fisiologia , Feminino , Masculino , Neurônios/fisiologia , Norepinefrina/sangue , Ratos Wistar
13.
Medicina (Kaunas) ; 55(8)2019 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-31394861

RESUMO

Background and Objectives: Spinal manipulations are interventions widely used by different healthcare professionals for the management of musculoskeletal (MSK) disorders. While previous theoretical principles focused predominantly on biomechanical accounts, recent models propose that the observed pain modulatory effects of this form of manual therapy may be the result of more complex mechanisms. It has been suggested that other phenomena like neurophysiological responses and the activation of the immune-endocrine system may explain variability in pain inhibition after the administration of spinal manipulative therapy (SMT). The aim of this paper is to provide an overview of the available evidence supporting the biological plausibility of high-velocity, low-amplitude thrust (HVLAT) on the immune-endocrine system. Materials and Methods: Narrative critical review. An electronic search on MEDLINE, ProQUEST, and Google Scholar followed by a hand and "snowballing" search were conducted to find relevant articles. Studies were included if they evaluated the effects of HVLAT on participants' biomarkers Results: The electronic search retrieved 13 relevant articles and two themes of discussion were developed. Nine studies investigated the effects of SMT on cortisol levels and five of them were conducted on symptomatic populations. Four studies examined the effects of SMT on the immune system and all of them were conducted on healthy individuals. Conclusions: Although spinal manipulations seem to trigger the activation of the neuroimmunoendocrine system, the evidence supporting a biological account for the application of HVLAT in clinical practice is mixed and conflicting. Further research on subjects with spinal MSK conditions with larger sample sizes are needed to obtain more insights about the biological effects of spinal manipulative therapy.


Assuntos
Sistema Endócrino/fisiologia , Sistema Imunitário/fisiologia , Manipulação da Coluna/efeitos adversos , Manipulação da Coluna/métodos , Sistema Endócrino/inervação , Sistema Endócrino/metabolismo , Humanos , Sistema Imunitário/inervação , Sistema Imunitário/metabolismo , Manejo da Dor/métodos , Manejo da Dor/normas , Doenças da Coluna Vertebral/complicações , Doenças da Coluna Vertebral/terapia , Resultado do Tratamento
14.
Vitam Horm ; 111: 105-129, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31421697

RESUMO

After millennia of knowledge of opium, it was only recently that endogenous substances called opioids with similar properties to opium and derivatives were discovered. The first to be discovered were enkephalins. In addition to the regulation of their synthesis and expression of receptors, an important mechanism for the regulation of their functions carried out by multiple proteolytic enzymes acting at all levels of their structure is described. The action of such enzymes, known as enkephalinases, is also regulated by endogenous and exogenous factors which ultimately affect the control of the enkephalins's action. For therapeutic purposes, it is not only necessary to develop specific inhibitors but also to acquire a deep knowledge of the influence that such factors exert on their activities. This knowledge could help us to establish adapted therapeutic strategies in the treatment of pain or other processes in which enkephalinases are involved. In this chapter, some of these regulatory factors are discussed, such as regional and subcellular distribution, developmental changes, diurnal variations, hormonal influences, stress, dietary factors or interactions with other neurotransmitters.


Assuntos
Neprilisina/metabolismo , Animais , Encéfalo/crescimento & desenvolvimento , Encéfalo/ultraestrutura , Química Encefálica/fisiologia , Ritmo Circadiano/fisiologia , Dieta , Sistema Endócrino/fisiologia , Encefalinas/fisiologia , Feminino , Homeostase , Humanos , Masculino , Neprilisina/análise , Manejo da Dor/métodos , Estresse Psicológico/enzimologia , Frações Subcelulares/química , Distribuição Tecidual
15.
Artigo em Inglês | MEDLINE | ID: mdl-31319168

RESUMO

American alligators (Alligator mississippiensis) mainly inhabit freshwater habitats but can be exposed to a wide range of salinities during storm surges, droughts or from alterations in freshwater flows. Although some salinization events last weeks, others only last a few days. This study assessed changes in the endocrine function of the renin-angiotensin-aldosterone system (RAAS) and steroid hormone production (steroidogenesis) in juvenile alligators exposed to brackish water (12‰) for 7 days. We quantified plasma levels of angiotensin II and the corticosteroids (aldosterone, corticosterone and 11-deoxycortisol). Various progestogens, androgens, and estrogens were further assessed. The protein expression for the RAAS enzymes, renin and angiotensin converting enzyme (ACE), was quantified immunohistochemically in kidney and lung tissue, respectively, and histology was performed on kidney, lung and gonad tissues. Finally, blood biochemistry parameters such as electrolyte levels and diagnostic indicators for dehydration, renal, and hepatic function were measured. Corticosterone, 11-deoxycortisol, Na+, Cl-, total protein, albumin, uric acid, and cholesterol levels were all significantly elevated in alligators exposed to brackish water compared with alligators in freshwater. The levels of 17ß-estradiol and estrone were significantly lowered while histology showed alterations in gonad tissue in the brackish water exposed group. In contrast, while there were no effects of exposure on aldosterone levels, angiotensin II was significantly reduced in brackish water exposed alligators. These results correlated with significantly decreased expressions for both renin and ACE in kidney and lung tissue. Overall, this study showed that short-term exposure of alligators to 12‰ brackish water has significant endocrine effects on juvenile alligators.


Assuntos
Jacarés e Crocodilos/fisiologia , Sistema Endócrino/fisiologia , Águas Salinas/farmacologia , Jacarés e Crocodilos/anatomia & histologia , Jacarés e Crocodilos/sangue , Animais , Sistema Endócrino/efeitos dos fármacos , Comportamento Alimentar , Feminino , Água Doce , Hormônios/sangue , Masculino , Especificidade de Órgãos , Sistema Renina-Angiotensina/efeitos dos fármacos , Esteroides/sangue , Estresse Fisiológico/efeitos dos fármacos , Fatores de Tempo
17.
Adv Exp Med Biol ; 1211: 61-68, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31309516

RESUMO

Long-term exposure to high altitude causes adaptive changes in several blood biochemical markers along with a marked body mass reduction involving both the lean and fat components. The aim of this study was to evaluate the impact of extended physical strain, due to extensive trekking at high altitude, on body composition, selected biomarkers in the blood, and the protective role of a high-protein diet in muscle dysfunction. We found that physical strain at high altitude caused a significant reduction in body mass and body fat, with a concomitant increase in the cross-sectional area of thigh muscles and an unchanged total lean body mass. Further, we found reductions in plasma leptin and homocysteine, while myoglobin, insulin, and C-reactive protein significantly increased. Creatine kinase, lactate dehydrogenase, and leptin normalized per body fat were unchanged. These findings demonstrate that high-altitude hypoxia, involving extended physical effort, has an impact on muscle function and body composition, facilitating sarcopenia and affecting body mass and fat distribution. It also activates pro-inflammatory metabolic pathways in response to muscular distress. These changes can be mitigated by a provision of a high-protein diet.


Assuntos
Adaptação Fisiológica , Altitude , Composição Corporal , Sistema Endócrino/fisiologia , Biomarcadores/sangue , Dieta Rica em Proteínas , Humanos , Hipóxia , Sarcopenia
18.
Animal ; 13(S1): s26-s34, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31280746

RESUMO

Colostrum plays an essential role in ensuring the survival, growth and health of piglets by providing energy, nutrients, immunoglobulins, growth factors and many other bioactive components and cells. Both colostrum yield and composition are highly variable among sows, yet mechanisms and factors that regulate colostrogenesis are not fully known. Unlike sow milk yield, sow colostrum yield is not highly determined by litter size and suckling intensity but is largely driven by sow-related factors. Colostrum synthesis is under hormonal control, with prolactin and progesterone concentrations prepartum having, respectively, positive and negative influences on colostrum yield. Less is known about the endocrine control of the end of colostrogenesis in swine, which is characterized by the closure of tight junctions in the mammary epithelium and the cessation of transfer of immunoglobulin G (IgG) into lacteal secretions. Recent studies indicate that exogenous hormones may influence colostrogenesis. Inducing parturition by injecting prostaglandin F2α on day 114 of gestation in combination with an oxytocin-like molecule reduced colostrum yield, and injection of prostaglandin F2α alone either reduced colostrum yield or had no effect. Injecting a supraphysiological dose of oxytocin to sows in the early postpartum period delayed the tightening of mammary tight junctions, thereby prolonging the colostral phase and increasing concentrations of IGF-I and IgG and IgA in early milk. The development of strategies to improve colostrum composition in swine through maternal feeding has been largely explored but very few attempts were made to increase colostrum yield. This is most likely because of the difficulty in measuring colostrum yield in swine. The fatty acid content of colostrum greatly depends on the amount of lipids provided in the sow diet during late gestation, whereas the fatty acid profile is largely influenced by the type of lipid being fed to the pregnant sow. Moreover, various ingredients that presumably have immuno-modulating effects (such as fish oil, prebiotics and probiotics) increased concentrations of IgG, IgA and/or IgM in sow colostrum when they were provided during the last weeks of gestation. Finally, there is some evidence that sow nutrition during late gestation may influence colostrum yield but this clearly warrants more research. This review emphasizes that although progress has been made in understanding the control of colostrogenesis in swine, and that strategies exist to manipulate fat and immunoglobulin contents of colostrum, ways to increase colostrum yield are still lacking.


Assuntos
Colostro/metabolismo , Sistema Endócrino/fisiologia , Ácidos Graxos/metabolismo , Leite/metabolismo , Suínos/fisiologia , Animais , Colostro/química , Dieta/veterinária , Feminino , Óleos de Peixe/metabolismo , Hormônios/metabolismo , Imunoglobulina A/imunologia , Imunoglobulina G/imunologia , Fator de Crescimento Insulin-Like I/metabolismo , Tamanho da Ninhada de Vivíparos , Leite/química , Estado Nutricional , Parto , Gravidez , Proteínas Recombinantes/metabolismo
19.
Gen Comp Endocrinol ; 284: 113212, 2019 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-31238076

RESUMO

In this review article, information about the development of the hypothalamo-hypophyseal axis, endocrine control of metamorphosis, and hormonal and pheromonal involvements in reproductive behavior in some amphibian species is assembled from the works conducted mainly by our research group. The hypothalamic and pituitary development was studied using Bufo embryos and larvae. The primordium of the epithelial hypophysis originates at the anterior neural ridge and migrates underneath the brain to form a Rathke's pouch-like structure. The hypothalamo-hypophyseal axis develops under the influence of thyroid hormone (TH). For the morphological and functional development of the median eminence, which is a key structure in the transport of regulatory hormones to the pituitary, contact of the adenohypophysis with the undeveloped median eminence is necessary. For the development of proopiomelanocortin-producing cells, contact of the pituitary primordium with the infundibulum is required. The significance of avascularization in terms of the function of the intermediate lobe of the pituitary was evidenced with transgenic Xenopus frogs expressing a vascular endothelial growth factor in melanotropes. Metamorphosis progresses via the interaction of TH, adrenal corticosteroids, and prolactin (PRL). We emphasize that PRL has a dual role: modulation of the speed of metamorphic changes and functional development of organs for adult life. A brief description about a novel type of PRL (1B) that was detected was made. A possible reason why the main hypothalamic factor that stimulates the release of thyrotropin is not thyrotropin-releasing hormone, but corticotropin-releasing factor is considered in light of the fact that amphibians are poikilotherms. As regards the reproductive behavior in amphibians, studies were focused on the courtship behavior of the newt, Cynops pyrrhogaster. Male newts exhibit a unique courtship behavior toward sexually developed conspecific females. Hormonal interactions eliciting this behavior and hormonal control of the courtship pheromone secretion are discussed on the basis of our experimental results.


Assuntos
Anfíbios/fisiologia , Hipotálamo/crescimento & desenvolvimento , Hipófise/crescimento & desenvolvimento , Comportamento Sexual Animal/fisiologia , Animais , Sistema Endócrino/fisiologia , Feminino , Masculino , Feromônios/metabolismo
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