Obestatin is a recently discovered peptide produced in the stomach, which was originally described to suppress food intake and decrease body weight in experimental animals. We investigated fasting plasma obestatin levels in normal weight, obese and anorectic women and associations of plasma obestatin levels with anthropometric and hormonal parameters. Hormonal (obestatin, ghrelin, leptin, insulin) and anthropometric parameters and body composition were examined in 15 normal weight, 21 obese and 15 anorectic women. Fasting obestatin levels were significantly lower in obese than in normal weight and anorectic women, whereas ghrelin to obestatin ratio was increased in anorectic women. Compared to leptin, only minor differences in plasma obestatin levels were observed in women who greatly differed in the amount of fat stores. However, a negative correlation of fasting obestatin level with body fat indexes might suggest a certain role of obestatin in the regulation of energy homeostasis. A significant relationship between plasma obestatin and ghrelin levels, independent of anthropometric parameters, supports simultaneous secretion of both hormones from the common precursor. Lower plasma obestatin levels in obese women compared to normal weight and anorectic women as well as increased ghrelin to obestatin ratio in anorectic women might play a role in body weight regulation in these pathologies., H. Zamrazilová, V. Hainer, D. Sedláčková, H. Papežová, M. Kunešová, F. Bellisle, M. Hill, J. Nedvídková., and Obsahuje bibliografii a bibliografické odkazy
Free fatty acids (FFAs) are natural ligands of the PPARγ2 receptor. FFA plasma concentration and composition may represent one of the factors accounting for high heterogeneity of conclusions concerning the effect of the Pro12Ala on BMI, insulin sensitivity or diabetes type 2 (DM2) susceptibility. Our objective was to investigate the relation and possible interactions between the Pro12Ala polymorphism and FFA status, metabolic markers, and body composition in 324 lean nondiabetic subjects (M/F: 99/225; age 32±11 years; BMI 23.9±4.0 kg/m2) with and without family history of DM2. Family history of DM2 was associated with lower % PUFA and slightly higher % MUFA. The presence of Pro12Ala polymorphism was not associated with fasting plasma FFA concentration or composition, anthropometric or metabolic markers of glucose and lipid metabolism in tested population. However, the interaction of carriership status with FFA levels influenced the basal glucose levels, insulin sensitivity and disposition indices, triglycerides, HDL-cholesterol and leptin levels, especially in women. The metabolic effects of 12Ala carriership were influenced by FFA levels – the beneficial role of 12Ala was seen only in the presence of low concentration of plasma FFA. Surprisingly, a high PUFA/SFA ratio was associated with lower insulin sensitivity, the protective effect of 12Ala allele was apparent in subjects with family history of DM2. On the basis of our findings and published data we recommend the genotyping of diabetic patients for Pro12Ala polymorphism of the PPARγ2 gene before treatment with thiazolidinediones and education of subjects regarding diet and physical activity, which modulate metabolic outcomes., B. Bendlová, D. Vejražková, J. Včelák, P. Lukášová, D. Burkoňová, M. Kunešová, J. Vrbíková, K. Dvořáková, K. Vondra, M. Vaňková., and Obsahuje bibliografii a bibliografické odkazy
Although the relationships between thyroid function and anthropometric parameters were studied in patients with thyroid disorders and in morbidly obese subjects, such data in normal healthy population are scarce. In our study, relationships between factors of body composition, fat distribution and age with hormones of the pituitary-thyroid axis were evaluated in a large, randomly selected sample of normal adult Czech population comprising of 1012 men and 1625 women. Our results exhibited weak, but significant relationships between body composition, body fat distribution and the parameters of pituitary-thyroid axis. Some of these associations were gender-specific. As shown by backward stepwise regression model, body fat distribution evaluated by centrality index (subscapular/triceps skinfold ratio) was negatively associated with free triiodothyronine (fT3) serum levels only in women, while a positive correlation of fT3 with BMI was specific for men. BMI was inversely related to free thyroxine (fT4) concentrations in women but not in men. The centrality index (CI) was positively related to TSH levels in both genders. The fT3/fT4 ratio, reflecting deiodinase activity, was inversely related to age and positively related to BMI in both genders, while the highly significant negative correlation between CI and fT3/fT4 ratio was specific for women., M. Dvořáková, M. Hill, J. Čeřovská, Z. Pobišová, R. Bílek, P. Hoskovcová, V. Zamrazil, V. Hainer., and Obsahuje bibliiografii a bibliografické odkazy
The prevalence of obesity is increasing worldwide at an alarming rate in both developed and developing countries. Obesity is a chronic complex disease of multifactorial origin resulting from a long-term positive energy balance, in which both genetic and environmental factors are involved. Genetically prone individuals are the first to accumulate fat in the present obesogenic environment. Obesity increases the risks of type 2 diabetes, hypertension, cardiovascular disease, dyslipidemia, arthritis, and several cancers and reduces the average life expectancy. Implementation of effective strategies in prevention and management of obesity should be come an important target in health care systems. Weight changes throughout life depend on the interaction of behavioral, genetic and environmental factors. Weight loss in response to weight management shows a wide range of interindividual variation which is largely influenced by genetic determinants. The strong control of weight loss by genotype was confirmed by twin and family studies. Recently, special attention has been paid to nutritional, hormonal, psychobehavioral and genetic factors which can predict the response to weight reduction programme. In this article currently available data on the role of obesity candidate gene polymorphisms in weight loss and maintenance are reviewed. It is believed that an elucidation of the genetic component in the prognosis of weight management could assist in the development of more effective and individually tailored therapeutic strategies., V. Hainer, H. Zamrazilová, J. Spálová, I. Hainerová, M. Kunešová, B. Aldhoon, B. Bendlová., and Obsahuje bibliografii a bibliografické odkazy
Steroid sulfatase (EC 3.1.6.2) is an important enzyme involved in steroid hormone metabolism. It catalyzes the hydrolysis of steroid sulfates into their unconjugated forms. This action rapidly changes their physiological and biochemical properties, especially in brain and neural tissue. As a result, any imbalance in steroid sulfatase activity may remarkably influence physiological levels of active steroid hormones with serious consequences. Despite that the structure of the enzyme has been completely resolved there is still not enough information about the regulation of its expression and action in various tissues. In the past few years research into the enzyme prope ties and regulations has been strongly driven by the discovery of its putative role in the indirect stimulation of the growth of hormone-dependent tumors of the breast and prostate., L. Kříž, M. Bičíková, R. Hampl., and Obsahuje bibliografii a bibliografické odkazy
Glucokinase (GCK) plays a key role in glucose metabolism. GCK mutations are known as a pathogenic cause of maturity-onset diabetes of the young type 2 (MODY2). These mutations are also found in gestational diabetics. The aim of our study was to assess the variability of the GCK gene in the Czech diabetic and control populations. We screened all 10 exons specific for the pancreatic isoform of glucokin ase (1a and 2-10) including the intron flanking regions in 722 subjects (in 12 patients with an unrecognised type of MODY and their 10 family members, 313 patients with diabetes mellitus type 2 (DM2), 141 gestational diabetics (GDM), 130 healthy offspring of diabetic parents, and 116 healthy controls without family history of DM2). In two MODY families we identified two mutations in exon 2 of the GCK gene: a novel mutation Val33Ala and the previously described mutation Glu40Lys. In other subgroups (excluding MODY families) we detected only intronic variants and previously described polymorphisms in exons 6 (Tyr215Tyr) and 7 (Ser263Ser), we did not find any known GCK pathogenic mutation. We observed no difference in the frequencies of GCK polymorphisms between Czech diabetic (DM2, GDM) and non- diabetic populations., P. Lukášová, J. Včelák, M. Vaňková, D. Vejražková, K. Andělová, B. Bendlová., and Obsahuje bibliografii a bibliografické odkazy
Ghrelin is a gut peptide produced mainly by stomach, well known to induce appetite stimulatory actions. Obestatin, a recently identified peptide derived from preproghrelin, was initially described to antagonize stimulatory effect of ghrelin on food intake. The postprandial response of obestatin and its relationship with ghrelin in humans remains unknown. We therefore investigated the postprandial response of obestatin and total ghrelin, acyl and desacyl ghrelin and neuropeptide Y (NPY) to a high-carbohydrate breakfast (1 604 kJ) in eight healthy women (age: 24.2±0.82 years; BMI 21.6±0.61 kg/m2). Blood samples were collected before the meal, and 30, 60, 90, 120 and 150 min after the breakfast consumption. Postprandial plasma obestatin concentrations significantly decreased compared with preprandial levels as well as total ghrelin concentrations and reached the lowest values 90 and 120 min after the meal consumption, respectively (p 0.05). Plasma acyl and desacyl ghrelin concentrations decreased after the breakfast and reached lowest values in 30 and 60 min, respectively (p<0.05). Plasma NPY concentrations were lower than preprandial levels 90 and 150 min after consuming breakfast (p<0.05). In conclusion, we demonstrated in healthy young women that plasma obestatin concentrations decrease similarly to ghrelin after a high-carbohydrate breakfast., D. Sedláčková, I. Dostálová, V. Hainer, L. Beranová, H. Kvasničková, M. Hill, M. Haluzík, J. Nedvídková., and Obsahuje bibliografii a bibliografické odkazy
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
TRH-like peptides are characterized by substitution of basic amino acid histidine (related to authentic TRH) with neutral or acidic amino acid, like glutamic acid, phenylalanin e, glutamine, tyrosine, leucin, valin, aspartic acid and asparagine. The presence of extrahypothalamic TRH-like peptides was reported in peripheral tissues including gastroin testinal tract, placenta, neural tissues, male reproductive system and certain endocrine tissues. Work deals with the biological function of TRH-like peptides in different parts of organisms where various mechanisms may serve for realisation of biological function of TRH-like peptides as negative feedback to the pituitary exerted by the TRH-like peptides, the role of pEEPam such as fertilization-promoting peptide, the mechanism influencing the proliferative ability of prostatic tissues, the neuroprotective and antidepressant function of TRH-like peptides in brain and the regulation of thyroid status by TRH-like peptides., R. Bílek, M. Bičíková, L. Šafařík., and Obsahuje bibliografii a bibliografické odkazy