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12. Melatonin negatively correlates with C-peptide after food intake
- Creator:
- Luboslav Stárka, Michaela Dušková, Rácz, B., Kateřina Šimůnková, Martin Hill, and Radmila Kancheva
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- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, endokrinologie, melatonin, peptidy, příjem potravy, metabolismus sacharidů, biorytmy, endocrinology, peptids, ingestion, sacharide metabolism, biological rhythms, C-peptid, 14, and 612
- Language:
- English
- Description:
- Melatonin plays a key role in the circadian timing system. At present, many other functions of melatonin are known. Question remains whether changes in endogenous melatonin may be associated with food intake. Hence, the levels of melatonin, C-peptide and glucose were followed during a daily regimen (16 hours) including standardized food intake using commercial kits. The diurnal profiles of the hormones and serum glucose were evaluated using ANOVA with Period and Subject as independent factors. Pearson’s correlations and using a multiple stepwise backward regression model consisting of the time factor as a polynomial, and serum C-peptide and glucose assessed the correlations between melatonin and the remaining parameters. Our results showed a significant negative correlation between melatonin and C-peptide. The profile of melatonin was physiological, decreasing after wake-up, showing minor changes during the daytime and increasing in the evening. As documented, lesser alterations were indicated in the course of the melatonin daytime profile, which may reflect periodic food intake. Food intake is not the primary factor influencing the melatonin course. While previous studies have mostly considered the protective effect of melatonin in diabetic subjects, our study brought the results suggesting food intake as a factor contributing to daytime melatonin variation in humans. However, the physiological role of melatonin association with food intake in daytime remains in question and should be further investigated., L. Stárka, M. Dušková, B. Rácz, K. Šimůnková, M. Hill, R. Kancheva., and Obsahuje bibliografii a bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
13. Metabolic profile and sex hormone binding globulin (SHBG) in different reproductive phases of Czech women and their relations to weight, body composition and fat distribution
- Creator:
- Kosková, I., Richard Petrásek, Karel Vondra, Michaela Dušková, and Luboslav Stárka
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- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, menopauza, menopause, lipid profile, SHBG, central adiposity, 14, and 612
- Language:
- English
- Description:
- n our study, 213 healthy Czech women aged 20 to 65 years were examined and divided into fully reproductive, premenopausal, menopausal and postmenopausal groups. In all subjects body composition was determined by classical anthropometry and metabolic profile was assessed. A total of 146 subjects completed 3-year longitudinal study. Total and LDL cholesterol increased and ratio HDL/total cholesterol decreased with age (p<0.001), most significantly in menopause. Triacylglycerols increased only up to menopause. HDL had a very slight trend to decrease in menopause and postmenopause. Fasting blood glucose level increased progressively (p<0.001), in postmenopause frequently exceeded normal range. Higher BMI, total fat mass and central fat indices were associated with higher total and LDL cholesterol, triacylglycerols, C-peptide, insulin and fasting blood glucose level (p<0.001; fasting blood glucose level to waist-to-hip ratio: p<0.01) and lower HDL cholesterol (p<0.001). Higher C-peptide and insulin were associated with lower HDL cholesterol and higher triacylglycerols (p<0.001). Fasting glucose correlated with LD L cholesterol (p<0.01). Higher SHBG was associated with higher HDL and lower LDL cholesterol (p<0.001). Hormone replacement treatment was related to lower fasting blood glucose level in postmenopausal women (p<0.01). Oral contraception is suggestive of a positive influence on lipid spectrum by increasing the ratio HDL/total cholesterol. Markers of lipid and carbohydrate metabolism are not only age-related, but they are also related to BMI, total fat mass and central fat indices. Therefore, preventive programs should be focused above all on menopausal women., I. Kosková, R. Petrásek, K. Vondra, M. Dušková, L. Stárka., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
14. Pregnanolone isomers, pregnenolone and their polar conjugates around parturition
- Creator:
- Jan Klak, Miroslav Hill, Antonín Pařízek, Helena Včeláková, Marie Bičíková, Richard Hampl, Tomáš Fait, Jarmila Šulcová, Pouzar, V., Radmila Kancheva, and Luboslav Stárka
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- Subject:
- Fyziologie člověka a srovnávací fyziologie, fyziologie, physiology, pregnanolone isomers, pregnenolone, maternal plasma, umbilical plasma, parturition, 14, and 612
- Language:
- English
- Description:
- The levels of four pregnanolone isomers and their polar conjugates and pregnenolone sulfate were measured in the plasma of 13 and 7 women at delivery with subarachnoidal and epidural analgesia, respectively, and in corresponding samples of umbilical plasma using a simple quadrupole GC/MS system with electron impact ionization (pregnenolone isomers), RIA following HPLC separation (pregnenolone) and specific RIA (pregnanolone sulfate). The concentration of epipregnanolone (3b-hydroxy-5b-pregnan-20-one) in both maternal and umbilical plasma was much lower than that of other pregnanolone isomers. The levels of 3b-hydroxy-pregnanolone isomers were significantly higher in the umbilical plasma than in the maternal, while the differences in 3a-hydroxy-isomers were insignificant. The differences in conjugates were insignificant with the exception of allopregnanolone, the levels of which were lower in umbilical plasma. In all the pregnanolone isomers, a significantly lower conjugated/unconjugated steroid ratio was found in the umbilical plasma than in the maternal plasma. In addition, time profiles of the steroids were measured around parturition and in the postpartum period in the maternal serum. Similarly, the levels of polar conjugates of all pregnanolone isomers were followed during parturition. Changes in concentrations of free steroids exhibited a similar pattern, with a fall primarily within the first hour after delivery. The decrease in conjugated steroids was shifted to the interval within the first hour and first day after delivery, and the changes were more pronounced. The time profiles of the conjugated/free steroid ratio exhibited a significant decrease within the first hour and the first day after delivery in all of the isomers investigated. A decrease was also observed in the ratio of 3a/3b- isomers and 5a/5b- isomers around parturition.The possible physiological consequences of the findings are indicated., J. Klak, M. Hill, A. Pařízek, H. Havlíková, M. Bičíková, R. Hampl T. Fait, J. Šulcová V. Pouzar, R. Kancheva, L. Stárka., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
15. Reduced levels of circulating 7α-hydroxy-dehydroepiandrosterone in treated adolescent obese patients
- Creator:
- Ludmila Máčová, Marie Bičíková, Hana Zamrazilová, Martin Hill, Hana Kazihnitková, Barbora Sedláčková, and Luboslav Stárka
- Format:
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, obezita, obesity, 11β-hydroxysteroid dehydrogenase 1 (11β-HSD 1), obesity, body mass index (BMI), 7-hydroxy-dehydroepiandrosterone (7-OH-DHEA), 7-oxo-dehydroepiandrosterone (7-oxo-DHEA), 14, and 612
- Language:
- English
- Description:
- Elevated levels of glucocorticoids lead to the development of obesity and metabolic syndrome. Local glucocorticoid levels are regulated through the enzyme 11 β -hydroxysteroid dehydrogenase 1 (11 β -HSD 1), an enzyme that regenerates active cortisol from inert cortis one. Increased expression of 11 β - HSD 1 in adipose tissue promotes higher body mass index (BMI), insulin resistance, hypertension, and dyslipidemia. Human 11 β - HSD 1 is also responsible for inter-conversion of 7-hydroxylate metabolites of dehydroepiandrosterone (7-OH-DHEA) to their 7-oxo-form. To better understanding the mechanism of the action, we focused on 7-OH- and 7-ox o-DHEA, and their circulating levels during the reductive treatment in adolescent obese patients. We determined plasma levels of 7 α -OH-DHEA, 7 β -OH- DHEA, and 7-oxo-DHEA in 55 adolescent patients aged 13.04- 15.67 years, BMI greater than 90 th percentile. Samples were collected before and after one month of reductive therapy. Circulating levels of 7 α -OH-DHEA decreased during the reductive therapy from 1.727 (1.614; 1.854 , transformed mean with 95 % confidence interval) to 1.530 nm ol/l (1.435; 1.637, p<0.05) in girls and from 1.704 (1.583; 1. 842) to 1.540 nmol/l (1.435; 1.659, p<0.05) in boys. With regard to the level of 7-oxo-DHEA, a significant reduction from 1. 132 (1.044; 1.231) to 0.918 nmol/l (0.844; 1.000, p<0.05) was found after the treatment, but only in boys. No significant difference in 7 β -OH-DHEA levels was observed. In conclusions, diminished levels of 7 α -OH-DHEA indicate its possible effect on activity of 11 β -HSD 1. Further studies are necessary to clarify whether competitive substrates for 11 β -HSD 1 such as 7 α -OH-DHEA could inhibit production of glucocorticoids and may be involved in metabolic processes leading to reduction of obesity., L. Máčová ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
16. Salivary cortisol in low dose (1 μg) ACTH test in healthy women: comparison with serum cortisol
- Creator:
- Kateřina Šimůnková, Richard Hampl, Miroslav Hill, Jiří Doucha, Luboslav Stárka, and Karel Vondra
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- Subject:
- Fyziologie člověka a srovnávací fyziologie, fyziologie, kortizol, physiology, cortisol, low dose ACTH test, salivary cortisol, total serum cortisol, transcortin, 14, and 612
- Language:
- English
- Description:
- To date, a single report has appeared on the use of salivary cortisol for adrenal function testing with a low dose ACTH, although 1 μg has become preferred as a more physiological stimulus than the commonly used 250 μg ACTH test. Our present study was aimed to obtain physiological data on changes of free salivary cortisol after 1 μg ACTH stimulation. This approach was compared with the common method based on the changes of total serum cortisol. Intravenous, low-dose ACTH test was performed in 15 healthy women (aged 22-40 years) with normal body weight, not using hormonal contraceptives, in the follicular phase of the menstrual cycle. Blood and saliva for determination of cortisol were collected before ACTH administration and 30 and 60 min after ACTH administration. Basal concentration of salivary cortisol (mean ± S.E.M., 15.9±1.96 nmol/l) increased after 1 μg ACTH to 29.1±2.01 nmol/l after 30 min, and to 27.4±2.15 nmol/l after 60 min. The differences between basal and stimulated values were highly significant (p<0.0001). The values of salivary cortisol displayed very little interindividual variability (p<0.04) in contrast to total serum cortisol values (p<0.0001) A comparison of areas under the curve (AUC) related to initial values indicated significantly higher AUC values for salivary cortisol than for total serum cortisol (1.89±0.88 vs. 1.22±0.19, p<0.01). Correlation analysis of serum and salivary cortisol levels showed a borderline relationship between basal levels (r=0.5183, p=0.0525); correlations after stimulation were not significant. Low-dose ACTH administration appeared as a sufficient stimulus for increasing salivary cortisol to a range considered as a normal adrenal functional reserve., K. Šimůnková, R. Hampl, M. Hill, J. Doucha, L. Stárka, K. Vondra., and Obsahuje bibliografii a bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
17. Steroid hormones in the development of postpartum depression
- Creator:
- Antonín Pařízek, Mikešová, M., Roman Jirák, Hill, M., Michal Koucký, Andrea Pašková, Velíková, M., Katarína Adamcová, Šrámková, M., Jandíková, H., Michaela Dušková, and Luboslav Stárka
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- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, poporodní deprese, testosteron, estrogeny, postpartum depression, testosterone, estrogens, neuroactive steroids, 14, and 612
- Language:
- English
- Description:
- Postpartum depression affects 10-15 % women after childbirth. There is no currently generally accepted theory about the causes and mechanisms of postpartum mental disorders. The principal hypothesis concerns the association with sudden changes in the production of hormones affecting the nervous system of the mother and, on the other hand, with the ability of receptor systems to adapt to these changes. We observed changes in steroidogenesis in the period ar ound spontaneous delivery. We collected three samples of maternal blood. The first sampling was 4 weeks prior to term; the second sampling was after the onset of uterine contractions (the beginning of spontaneous labour); the third sampling was during the third stage of labour (immediately after childbirth). Additionally, we collected mixed umbilical cord blood. The almost complete steroid metabolome was analyzed by gas chroma tography-mass spectrometry followed by RIA for some steroids. Mental changes in women in the peripartum period were observed using the Hamilton Depression Rating Scale. The local Ethics Committee approved the study. We found already th e changes in androgens levels correlating with postpartum mood disorders four weeks prior to childbirth. The strongest correlations between steroid and postpartum mood change were found in venous blood samples collected from mothers after childbirth and from umbilical cord blood. The main role played testosterone, possibly of maternal origin, and estrogens originating from the fetal compartment. These results suggest that change s in both maternal and fetal steroidogenesis are involved in the development of mental changes in the postpartum period. Descriptions of changes in steroidogenesis in relation to po stpartum depression could help clarify the causes of this disease, and changes in some steroid hormones are a promising marker of mental changes in the postpartum period., A. Pařízek, M. Mikešová, R: Jirák, M. Hill, M. Koucký, A. Pašková, M. Velíková, K. Adamcová, M. Šrámková, H. Jandíková, M. Dušková, L. Stárka., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
18. Steroid metabolome in the umbilical cord: is it necessary to differentiate between arterial and venous blood?
- Creator:
- Andrea Pašková, Antonín Pařízek, Martin Hill, Velíková, M., Kubátová, J., Martina Dušková, Adamcová, K., Michal Koucký, Šimjak, P., Černý, A., and Luboslav Stárka
- Format:
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, steroidy, práce, krev, steroids, labor, blood, metabolome, GC-MS, 14, and 612
- Language:
- English
- Description:
- Steroids are important marker s in pregnancy. Although estimating their levels separately in umbilical arterial (UA) and venous blood (UV) enable more precise insights into the functioning fetoplacental unit compared to using mixed umbilical blood (UM), selective aspiration of UA and UV is technically more demanding than collecting UM. We measured the levels of 67 unconjugated steroids and steroid polar conjugates in UA and UV using GC-MS in 80 women giving birth within weeks 28 to 42 of gestation. The samples were sorted into three groups: women entering labor within weeks 28- 32 (group A, n=19), weeks 33-37 (group B, n=19), and weeks 38-42 (group C, n=42) of gestation, respectively. The preterm labo rs were due to pathologies unrelated to steroid status. Most unconjugated steroids exhibited pronounced arteriovenous differences (AVD). The AVD were less distinct in more stable steroid conjugates. Most steroids positively correlate with gestational age, but unconjugated 5 β -reduced pregnanes show negative correlations, as do testosterone and androstenediol, substrates for the placental synthesis of estrogens. Tight correlations be tween steroids in UA and UV indicate that steroid measurements in UA, UV and UM can be accurately derived from each other, which is important for the diagnostics of steroid related diseases in newborns., A. Pašková ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
19. The effect of leptin on bone - an evolving concept of action
- Creator:
- Veronika Cirmanová, Milan Bayer, Luboslav Stárka, and Kateřina Zajíčková
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- 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