Monoaminergic neurotransmitter 5-hydroxytryptamine (5-HT), also known as serotonin, plays im portant roles in modulating the function of the olfactory system. However, thus far, the knowledge about 5-HT and its receptors in olfactory receptor neurons (ORNs) and their physiological role have not been fully characterized. In the present study, reverse transcription- polymerase chain reaction (RT-PCR) analysis revealed the presence of 5-HT 1A and 5-HT 1B receptor subtypes in mouse olfactory epithelium at the mRNA level. With subtype selective antibodies and standard immunohistochemical techniques, both receptor subtypes were found to be positively labeled. To further elucidate the molecular mechanisms of 5-HT act on the peripheral olfactory transduction, the whole-cell patch clamp techniques were used on freshly isolated ORNs. We found that 5-HT decreased the magnitude of outward K + current in a dose- dependent manner and these inhi bitory effects were markedly attenuated by the 5-HT 1A receptor blocker WAY-100635 and the 5-HT 1B receptor antagonist GR55562. These data suggested that 5-HT may play a role in the modu lation of peripheral olfactory signals by regulating outward potassium currents, both 5-HT 1A and 5-HT 1B receptors were involved in this regulation., S. Gao, ... [et al.]., and Obsahuje seznam literatury
Neurotransmitter substrate of spatial cognition belongs to current topics in behavioral neuroscience. The present study examined the effects of serotonin depletion with p-chlorophenylalanine on learning of rats in active place avoidance, a spatial task requiring allothetic mapping and cognitive coordination and highly dependent upon hippocampus. Serotonin depletion transiently increased locomotor activity in response to footshocks, but it did not change the avoidance efficiency measured by three spatial parameters. These results suggest that serotonin neurotransmission is not crucial for cognitive coordination and allothetic learning, i.e. the processes, which are crucial for active place avoidance performance., T. Petrásek, A. Stuchlík., and Obsahuje seznam literatury
Recent studies have demonstrated that adipocyte fatty acid binding proteins (FABP) may play a role in the etiopathogenesis of insulin resistance. The aim of our study was to assess serum FABP levels in obese patients with type 2 diabetes mellitus (T2DM) before and after 3 months of treatment with PPAR-α agonist fenofibrate (F) and to explore the relationship of FABP to biochemical parameters and measures of insulin sensitivity assessed by hyperinsulinemic-isoglycemic clamp. We measured biochemical parameters by standard laboratory methods, insulin sensitivity by hyperinsulinemic-isoglycemic clamp and serum concentrations of FABP by commercial ELISA kit in 11 obese females with T2DM before and after three months of treatment with PPAR-α agonist fenofibrate and in 10 lean healthy control women (C). Serum FABP levels were 2.5-fold higher in T2DM group relative to C and were not affected by fenofibrate treatment (C: 20.6±2.1 μg/l, T2DM before F: 55.6±5.7 μg/l, T2DM after F: 54.2±5.4 μg/l, p<0.0001 for C vs. T2DM before F). Hyperinsulinemia during the clamp significantly suppressed FABP levels in both C and T2DM group. FABP levels positively correlated with BMI, triglyceride levels, blood glucose, glycated hemoglobin, atherogenic index and insulin levels. An inverse relationship was found between FABP and HDL levels, metabolic clearance rate of glucose, M/I and MCRglc/I sensitivity indexes. We conclude that FABP levels are closely related to BMI, parameters of insulin sensitivity, HDL levels and measures of diabetes compensation. This combination makes FABP a valuable marker of metabolic disturbances in patients with type 2 diabetes mellitus., M. M. Haluzík ... [et al.]., and Obsahuje seznam literatury
Five intratesticular sex steroids (testosterone, dihydrotestosterone, androstenedione, estradiol and epitestosterone) along with six serum hormones (LH, FSH, prolactin, SHBG, testosterone and estradiol) were determined in 84 non-obstructive azoospermic men, in order to evaluate to what extent serum and testicular tissue as well as individual hormones in the same material mutually correlate. With exception of androstenedione, tight correlations were found among tissue content of sex steroids, while only weak correlation was recorded between serum and testicular concentrations of major sex steroids testosterone and estradiol. It points to importance of measurement of intratesticular steroids in combination with examination of sperm parameters for assessment of testicular function and spermatogenesis., J. Heráček, V. Sobotka, L. Kolátorová, J. Kočárek, R. Hampl., and Obsahuje bibliografii
Omentin is a novel adipokine with insulin-sensitizing effects expressed predominantly in visceral fat. We investigated serum omentin levels and its mRNA expression in subcutaneous adipose tissue (SCAT) of 11 women with type 2 diabetes mellitus (T2DM), 37 obese non-diabetic women (OB) and 26 healthy lean women (C) before and after various weight loss interventions: 2-week very-low-calorie diet (VLCD), 3-month regular exercise and laparoscopic sleeve gastrectomy (LSG). At baseline, both T2DM and OB groups had decreased serum omentin concentrations compared with C group while omen tin mRNA expression in SCAT did not significantly differ among the groups. Neither VLCD nor exercise significantly affected serum omentin concentrations and its mRNA expression in SCAT of OB or T2DM group. LSG significantly increased serum omen tin levels in OB group. In contrast, omentin mRNA expression in SCAT was significantly reduced after LSG. Baseline fasting serum omentin levels in a combined group of the studied subjects (C, OB, T2DM) negatively correlated with BMI, CRP, insulin, LDL-cholesterol, triglycerides and leptin and we re positively related to HDL- cholesterol. Reduced circulating omentin levels could play a role in the etiopathogenesis of obesity and T2DM. The increase in circulating omentin levels and the decrease in omentin mRNA expression in SCAT of obese women after LSG might contribute to surgery-induced metabolic improvements and sustained reduction of body weight., M. Urbanová ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
The aim of our study was to measure serum concentrations of fibroblast growth factor 19 (FGF-19) in patients with obesity (OB), obesity and type 2 diabetes mellitus (T2DM) and healthy subjects (C) at baseline and after selected interventions. We measured serum FGF-19 levels and other biochemical and hormonal parameters in 29 OB and 19 T2DM females and 30 sex- and age-matched control subjects. The interventions were acute hyperinsulinemia during isoglycemic-hyperinsulinemic clamp (n=11 for T2DM and 10 for C), very-low calorie diet (VLCD, n=12 for OB) and 3 months treatment with PPAR- α agonist fenofibrate (n=11 for T2DM). Baseline serum FGF-19 levels were significantly lower in OB relative to C group (132.1±12.7 vs. 202.2±16.7 pg/ml, p<0.05), while no significant difference was observed between T2DM and OB or control group. Acute hyperinsulinemia tended to decrease FGF-19 levels in both healthy and T2DM subjects. Three weeks of VLCD in OB group had no significant effect on FGF-19, whereas three months of fenofibrate treatment markedly reduced FGF-19 levels in T2DM patients (194.58±26.2 vs. 107.47±25.0 pg/ml, p<0.05). We conclude that FGF-19 levels in our study were at least partially dependent upon nutritional status, but were not related to parameters of glucose metabolism or insulin sensitivity., M. Mráz ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
Salivary cortisol reflects the free fraction of serum cortisol. Monitoring salivary cortisol may be a promising alternative method for assessing serum cortisol in some clinical situations. We aimed to compare the reliability of salivary vs. serum cortisol during ACTH test. 84 subjects (mean age 63.2; 24-89 years; n=66 males) suspected for adrenocortical insufficiency underwent an ACTH test. Patients were divided based on peak serum cortisol into hypocortical group with cortisol <500 nmol/l and to reference group cortisol >500 nmol/l. Median serum cortisol levels in reference gr oup were 445, 766, and 902 nmol/l at 0, 30, and 60 minutes, respecti vely, and in hypocortical group were 256, 394, and 453 nmol/l. Median salivary cortisol levels were 19.02, 40.02, and 62.1 nmol/l in reference group, and 9.60, 14.08, and 13.28 nmol/l in hypoco rtical group. Obtained values showed good correlation between serum and salivary cortisol (p<0.0001). The percentage of explained variability R 2 (coefficient of determination for linear model) representing a measure of agreement betwee n experimental values and predictions for repeated measur es ANOVA, was significantly higher (p=0.021) for serum cortisol (R 2 =93.4 %) when compared to the salivary cortisol (R 2 =89.3 %). A stronger discriminating power of serum versus salivary cortisol suggests that it seems to be slightly, but statistically significantly more appropriate marker of adrenocortical reserve in ACTH test., M. Kosák ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
a1_The decreased oxidizability of plasma lipoproteins is related to the increased vitamin E intake and its association with a relatively lower incidence of coronary heart disease has been proposed. We investigated the effect of the in vivo vitamin E supplementation on the oxidizability of serum lipids in patients with ischemic heart disease and a moderate hypercholesterolemia. Thirty-two patients (16 males and 16 postmenopausal women) participated in this placebo-controlled, randomized trial. They were treated with 400 mg vitamin E/day for 6 weeks. The copper-induced serum lipid oxidizability ex vivo was assessed by measuring conjugated diene formation at 245 nm. We also measured vitamin E, malondialdehyde (MDA) and uric acid concentrations in the plasma. Because of observed significant differences in parameters of serum lipid oxidizability (lag time and maximal rate of oxidation), plasma a-tocopherol and MDA levels between male patients and postmenopausal women supplemented with vitamin E, the results were compared between both genders. Six weeks of vitamin E supplementation significantly increased plasma vitamin E levels (by 87 %) in male patients but in postmenopausal women only by 34 %. Concomitantly with increased plasma levels of vitamin E the decrease in plasma MDA levels was observed in male patients (decrease by 20 %; p=0.008), but in postmenopausal women the decrease did not attain statistical significance. Plasma uric acid levels were not apparently changed in placebo or vitamin E supplemented groups of patients. The changes in ex vivo serum lipid oxidizability after vitamin E, supplementation have shown a significantly prolonged lag time (by 11 %; p=0.048) and lowered rate of lipid oxidation (by 21 %; p=0.004) in male patients in comparison with postmenopausal women., a2_Linear regression analysis revealed a significant correlation between plasma vitamin E levels and the lag time (r=0.77; p=0.03) and the maximal rate of serum lipid oxidation (r=-0.70; p=0.05) in male patients. However, in postmenopausal women the correlations were not significant. We conclude that 400 mg vitamin E/day supplementation in patients with ischemic heart disease and a moderate hypercholesterolemia influenced favorably ex vivo serum lipid oxidation of male patients when compared with postmenopausal women. The observed differences between both genders could be useful in the selection of the effective vitamin E doses in the prevention of coronary heart disease., A. Nagyová, V. Mongiellová, Z. Krivošíková, P. Blažíček, V. Spustová, M. Gajdoš, R. Dzúrik., and Obsahuje bibliografii
Ghrelin is a new endogenous ligand for the growth hormone secretagogue receptor. It activates the release of growth hormone from the pituitary and it also participates in the regulation of energy homeostasis. The aim of the study was to characterize changes in serum ghrelin levels in obese subjects and their relationship to the serum levels of leptin and soluble leptin receptor. Eight obese patients (6 women and 2 men) with body mass index (BMI) 40.313.4 kg.m-2 and eight healthy controls (5 women and 3 men) with BMI 22.7±1.3 kg.m-2 were examined. The ghrelin serum levels (165.0±58.1 vs. 343.37±81.96; p<0.001) and soluble leptin receptor serum levels (7.25±3.44 vs. 21.80±4.99; p<0.0001) were significantly lower in obese patients. The leptin serum levels (23.45±12.90 vs. 6.41±2.96; p<0.005) were significantly higher compared to the lean subject group. In both measured groups the levels of serum leptin significantly positively correlated with BMI. We proved a significantly lower serum ghrelin levels in the group of obese patients in comparison with the control group., M. Rosická, M. Kršek, M. Matoulek, Z. Jarkovská, J. Marek, V. Justová, Z. Lacinová., and Obsahuje bibliografii