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42. The effect of leptin on bone - an evolving concept of action

Creator:
Veronika Cirmanová, Milan Bayer, Luboslav Stárka, and Kateřina Zajíčková
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Fyziologie člověka a srovnávací fyziologie, endokrinologie, leptin, kosti, sympatický nervový systém, neuropeptidy, endocrinology, bones, sympathetic nervous system, neuropeptids, 14, and 612
Language:
English
Description:
Leptin, a cytokine-like hormone secreted by adipocytes, is known to regulate food intake but has also emerged as a significant factor in the regulation of bone mass. In humans, states of energy deprivation with low serum leptin have been associated with low bone mass. In mice, leptin deficiency led to increased trabecular bone mass with overall decrease in cortical bone. Leptin regulates bone metabolism indirectly in the hypothalamus thereby activating the sympathetic nervous system (SNS). In addition to the SNS, leptin also interacts with various hypothalamic neuropeptides, such as cocaine- and amphetamine-regulated transcript, neuropeptide Y and/or neuromedin U, which might modulate the effects of leptin on bone. In osteoblasts sympathetic signaling is further gated by the transcriptional factors called molecular clock. As a result, bone loss is accelerated showing that the central effect of leptin seems to be antiosteogenic. Additionally, leptin has a direct anabolic effect within the bone driving the differentiation of bone marrow stem cells into the osteoblastic cell lineage. Besides the interaction between the central and peripheral pathways, the overall effect of leptin on bone might be bimodal depending on leptin serum concentrations. Regulatory pathways triggering osteoblast activity might open new possibilities for anabolic treatment of osteoporosis., V. Cirmanová, M. Bayer, L. Stárka, K. Zajíčková., and Obsahuje bibliografii a bibliografické odkazy
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

43. The evolution of taste and perinatal programming of taste preferences

Creator:
Štěpán Podzimek, Michaela Dušková, Zdeněk Broukal, Rácz, B, Luboslav Stárka, and Jana Dušková
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
chuť, taste, taste perception, flavor preference, salty, sweet, sour, umami, bitter, 14, and 612
Language:
English
Description:
Taste is important for food intake. The fetus first experiences taste through amniotic fluid, and later via mother’s milk. Early human experience with taste has a key importance for later acceptance of food. Dietary behavior is determined by the interaction of many different factors. The development of the olfactory and taste receptors begins at 7-8 weeks of gestation. An early sensitive period probably exists when flavor preference is established. Sweet taste is preferred in early childhood; this is the reason why children are at increased risk of over-consuming saccharides. Gustatory sensitivity declines with age. The threshold for the perception of each basic taste differs, and is established genetically. In this review, we summarize published data on taste preferences and its development and changes during life., Š. Podzimek, M. Dušková, Z. Broukal, B. Rácz, L. Stárka, J. Dušková., and Obsahuje bibliografii
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

44. The influence of smoking and cessation on the human reproductive hormonal balance

Creator:
Jandíková, H., Michaela Dušková, and Luboslav Stárka
Format:
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Type:
article, články, journal articles, model:article, and TEXT
Subject:
Fyziologie člověka a srovnávací fyziologie, kouření, steroidy, plodnost, smoking, steroids, fertility, anti-estrogenic effect, 14, and 612
Language:
English
Description:
Smoking is the most widespread substance dependence in the world. Nicotine and some other components of the cigarette smoke cause various endocrine imbalances, and have negative effects on pituitary, thyroid, adrenal, testicular and ovarian functions. Here, we examined studies that describe the influence of smoking and smoking cessation on the male and female reproductive systems. We also focused on studies providing an account of differences in cessation success rates between men and women. In men, the most common effects associated with smoking are erectile dysfunction and decreasing spermiogram quality. Several groups have studied the effects of cigarette smoking on testosterone levels in men. However, the results have been conflicting. In women, nicotine has an antiestrogen effect and increases the ratio of androgens to estrogens throughout life. Beside nicotine, other cigarette toxins also cause dysregulation of reproductive and hormonal system, and essentially influence the probability of a successful pregnancy not only in cases of assisted reproduction but also in healthy women. Tobacco addiction is one of the forms of addiction that are generally thought to be different for men and for women. Women are less successful than men in quitting smoking, and nicotine replacement therapy is less effective in female smokers. We also summarize recent studies that have indicated possible reasons., H. Jandíková, M. Dušková, L. Stárka., and Obsahuje bibliografii
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

45. The origin of 7α-hydroxy-dehydroepiandrosterone and its physiological role: a history of discoveries

Creator:
Luboslav Stárka
Format:
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Type:
article, články, journal articles, model:article, and TEXT
Subject:
Fyziologie člověka a srovnávací fyziologie, fyziologie, physiology, 11β-hydroxysteroid dehydrogenase, CYP7B, immunomodulatory effects, occurrence, dehydroepiandrosterone, 7α-hydroxy-dehydroepiandrosterone, neurosteroid, 14, and 612
Language:
English
Description:
Nearly 60 years has elapsed since the first isolation and identification of 7α-hydroxy-dehydroepiandrosterone, and in that time much information has been gained on its occurrence, metabolism, ontogeny, immunomodulatory activity, cell proliferation, cortisol control in local tissues and neuroactivity. Additional knowledge about this steroid may elucidate its role in obesity, neurodegenerative disturbances such as Alzheimer’s disease, or psychiatric disorders such as schizophrenia or depression. This review aims to provide a comprehensive summary of the available literature on 7α-hydroxydehydroepiandrosterone., L. Stárka., and Obsahuje bibliografii
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

46. The quantitation of 7β-hydroxy-epiandrosterone in the plasma and seminal plasma of men with different degrees of fertility

Creator:
Jana Vítků, Lucie Kolátorová Sosvorová, Ricco, C, Ferroud, C, Hennebert, O, Škodová, T, Jiří Heráček, and Luboslav Stárka
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
steroidy, rozmnožování (biologie), steroids, reproduction, 7β-hydroxy-epiandrosterone, sperm quality, steroidogenesis, seminal plasma, 14, and 612
Language:
English
Description:
7β-hydroxy-epiandrosterone (7β-OH-EpiA) is an endogenous androgen metabolite that has been shown to exert neuroprotective, anti-inflammatory and anti-estrogenic effects. However, to the best of our knowledge no information is available about this androgen steroid in relation to sperm quality. We analyzed 7β-OH-EpiA in plasma and seminal plasma using a newly developed isotope dilution ultra-high performance liquid chromatography - mass spectrometry method. Validation met the requirements of FDA guidelines. Levels of 7β-OH-EpiA were measured in 191 men with different degrees of infertility. One-way analysis of variance followed by multiple comparison and correlation analysis adjusted for age, BMI and abstinence time were performed to evaluate the relationships between this steroid and sperm quality. Concentrations of 7β-OH-EpiA in seminal plasma were significantly higher in severely infertile men in comparison with healthy men and slightly infertile men. The same trend was found when blood plasma was evaluated. Furthermore, plasma 7β-OH-EpiA negatively correlated with sperm concentration (-0.215; p<0.01) and total count (-0.15; p<0.05). Seminal 7β-OH-EpiA was negatively associated with motility (-0.26; p<0.01), progressively motile spermatozoa (-0.233; p<0.01) and nonprogressively motile spermatozoa (-0.188; p<0.05). 7β-OH-EpiA is associated with lower sperm quality and deserves more research in that respect., J. Vitku, L. Kolatorova, C. Ricco, C. Ferroud, O. Hennebert, T. Skodova, J. Heracek, L. Starka., and Obsahuje bibliografii
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

47. The role of steroid hormones in the development of intrahepatic cholestasis of pregnancy

Creator:
Antonín Pařízek, Michaela Dušková, Libor Vítek, Šrámková, M., Hill, M., Adamcová, K., Šimják, P., Černý, A., Kordová, Z., Vráblíková, H., Boudová, B., Michal Koucký, Karin Malíčková, and Luboslav Stárka
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Fyziologie člověka a srovnávací fyziologie, cholestáza, selen, těhotenství, cholestasis, selenium, pregnancy, allopregnanolone - epiallopregnanolone, 17β-estradiol, farnesoid, receptor, leaky gut in pregnancy, 14, and 612
Language:
English
Description:
Intrahepatic cholestasis of pregnancy (ICP) is a disorder of liver function, commonly occurring in the third trimester but sometimes also as soon as the end of the second trimester of pregnancy. Symptoms of this disorder include pruritus, plus abnormal values of bile acids and hepatic transaminases. After birth, symptoms disappear and liver function returns to normal. Though ICP is relatively non-complicated and often symptomatically mild from the point-of-view of the mother, it presents a serious risk to the fetus, making this disease the subject of great interest. The etiology and pathogenesis of ICP is multifactorial and as yet not fully elucidated. Hormonal factors likely play a significant role, along with genetic as well as exogenous factors. Here we summarize the knowledge of changes in steroid hormones and their role in the development of intrahepatic cholestasis of pregnancy. In addition, we consider the role of exogenous factors as possible triggers of steroid hormone changes, the relationship between metabolic steroids and bile acids, as well as the combination of these factors in the development of ICP in predisposed pregnant women., A. Pařízek, M. Dušková, L. Vítek, M. Šrámková, M. Hill, K. Adamcová, P. Šimják, A. Černý, Z. Kordová, H. Vráblíková, B. Boudová, M. Koucký, K. Malíčková, L. Stárka., and Obsahuje bibliografii
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

48. The role of stress hormones in dental management behavior problems

Creator:
Michaela Dušková, Vašáková, J., Jana Dušková, Jana Kaiferová, Zdeněk Broukal, and Luboslav Stárka
Format:
print, bez média, and svazek
Type:
article, články, journal articles, model:article, and TEXT
Subject:
Fyziologie člověka a srovnávací fyziologie, fobie, strach, úzkost, kortizol, phobias, fear, anxiety, cortisol, dental treatment, adrenals, catecholamines, 14, and 612
Language:
English
Description:
Dental management behavior problems are thought to be both multifactorial and multidimensional, consisting of physiological, behavioral and cognitive components. The stress response to pain or even the anticipation of distress initiates activation of the hypothalamic-pituitary-adrenal axis and causes an increase of cortisol and catecholamines. The literature on the role of hormones in dental management behavior problems comprises about one hundred papers, which have mainly been focused on this activation of the HPA axis in various situations in dental care. They have generally used salivary cortisol as a marker of the activity of the HPA axis, sometimes combined with salivary alpha amylase. Here we summarize the literature data on the role of stress hormones in dental management behavior problems., M. Dušková, J. Vašáková, J. Dušková, J. Kaiferová, Z. Broukal, L. Stárka., and Obsahuje bibliografii
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

49. The steroid metabolome in men with mood and anxiety disorders

Creator:
Michaela Dušková, Hill, M., Marie Bičíková, Šrámková, M., Daniela Řípová, Mohr, P., and Luboslav Stárka
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Fyziologie člověka a srovnávací fyziologie, steroidní hormony, steroid hormons, allopregnanolone, dehydroepiandrosterone, affective depression, anxiosity, steroid sulfates, steroid conjugates, 14, and 612
Language:
English
Description:
The mood and behavior of individuals result from an orchestra of many factors. Among them steroids play an important role; however, only several common hormones have been investigated in this respect. It has been demonstrated that some steroid metabolites long considered merely the products of steroid hormone metabolism in fact possess considerable activity in the CNS. For this reason we studied the steroid metabolome including 50 analytes in 20 men with depression, 20 men with anxiety and 30 healthy controls. Significant differences were found not only between controls and men with either depression or anxiety, but also between men with depression and anxiety. Particularly striking were those steroids until now not generally associated with depression or anxiety, namely conjugated steroid forms, especially sulfates., M. Dušková, M. hill, M. Bičíková, M. Šrámková, D. Řípová, P. Mohr, L. Stárka., and Obsahuje bibliografii
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

50. The steroid spectrum during and after quitting smoking

Creator:
Jandikova, H., Michaela Dušková, Kateřina Šimůnková, Racz, B., Hill, M., Eva Králíková, Karel Vondra, and Luboslav Stárka
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Fyziologie člověka a srovnávací fyziologie, muži, odvykání kouření, predikce, testosteron, men, smoking cessation, prediction, testosterone, SHBG, 14, and 612
Language:
English
Description:
Addiction to tobacco results in an imbalance of endocrine homeostasis in both sexes. This can also have impacts on fertility problems. The male reproductive system is less susceptible than that of females, with a worsening spermiogram in smokers, the most cited effect in the literature. However, the literature is inconsistent as to the effects of smoking on steroid hormone levels in men, and there is very little data on the effects of quitting smoking in men. In this study we followed 76 men before quitting smoking, and then after 6, 12, and 24 weeks and 1 year of abstinence. We measured basic anthropomorphic data and steroid hormone levels along with steroid neuroactive metabolites using GC-MS. We demonstrate lower androgen levels in men who smoke, and these changes worsened after quitting smoking. There was a drop in SHBG already in the first week of non-smoking, and levels continued to remain low. Male smokers have lower androgen levels compared to non-smokers. The lower the initial level of androgen, the lower the likelihood of success in quitting smoking. Changes in steroid hormones proved to be a promising marker for the prediction of success in quitting smoking., H. Jandikova, M. Duskova, K. Simunkova, B. Racz, M. Hill, E. Kralikova, K. Vondra, L. Starka., and Obsahuje bibliografii
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public