a1_Leptin regulates energy homeostasis and body weight by balancing energy intake and expenditure. It was recently reported that leptin, released into the gut lumen during the cephalic phase of gastric secretion, is capable of initiating intestinal nutrient absorption. Vagal afferent neurons also express receptors for both CCK and leptin, which are believed to interact in controlling food intake. The present study was undertaken to investigate the central and peripheral effects of leptin on gastric emptying rate. Under anesthesia, male Sprague-Dawley rats (250-300 g) were fitted with gastric Gregory cannulas (n=12) and some had additional cerebroventricular cannulas inserted into their right lateral ventricles. Following recovery, the rate of gastric emptying of saline (300 mOsm/kg H2O) was determined after instillation into the gastric fistula (3 ml, 37°C, containing phenol red, 60 mg/l as a non-absorbable dilution marker). Gastric emptying rate was determined from the volume and phenol red concentrations recovered after 5 min. Leptin, injected intraperitoneally (ip; 10, 30, 60, 100 μg/kg) or intracerebroventricularly (icv; 5, 15 μg/rat) 15 min before the emptying, delayed gastric emptying rate of saline at the dose of 30 μg/kg or 15 μg/rat (p<0.001). When CCK 1 receptor blocker L-364,718 (1 mg/kg, ip), CCK 2 receptor blocker L-365,260 (1 mg/kg, ip) or adrenergic ganglion blocker bretylium tosylate (15mg/kg, ip) was administered 15 min before ip leptin (30 μg/kg) injections, leptin-induced delay in gastric emptying was abolished only by the CCK 1 receptor blocker (p<0.001)., a2_However, the inhibitory effect of central leptin on gastric emptying was reversed by adrenergic blockade, but not by either CCK antagonists. Our results demonstrated that leptin delays gastric emptying. The peripheral effect of leptin on gastric motility appears to be mediated by CCK 1 receptors, suggesting the release of CCK and the involvement of vagal afferent fibers. On the other hand, the central effect of leptin on gastric emptying is likely to be mediated by adrenergic neurons. These results indicate the existence of a functional interaction between leptin and CCK receptors leading to inhibition of gastric emptying and short-term suppression of food intake, providing an additional feedback control in producing satiety., B. Çakir, Ö. Kasimay, E. Devseren, B. Ç. Yeğen., and Obsahuje bibliografii a bibliografické odkazy
Obesity in children is accompanied by increased circulating leptin concentrations. Girls have higher leptin concentrations than boys. The aim of our study was to compare serum leptin levels before and after a five-week weight reduction program and to study the relationship of leptin levels, serum total cholesterol, and androgens (testosterone, dehydroepiandrosterone, dehydroepiandrosterone sulphate) in 33 obese boys (age: 12.71.97 years, BMI: 30.46±4.54) and 66 obese girls (age: 12.7±2.51 years, BMI: 29.31±4.62). We found that serum leptin concentrations in obese children were significantly decreased after a weight reduction program (before 20.79±9.61 ng/ml, after 13.50±8.65 ng/ml in girls; before 12.25±10.09 ng/ml and after 5.18±3.56 ng/ml in boys, p<0.0001 in both genders). Leptin levels correlated positively with the body mass index before and after weight reduction. There was a positive association in obese boys and a negative one in obese girls between leptin levels and the WHR (waist to hip circumference ratio). Serum leptin also shows a strong relationship to fat distribution (p = 0.02 in boys, p<0.0001 in girls). No significant correlation was found between leptin concentrations and total cholesterol or androgens. We confirmed that leptin is a sensitive parameter of body composition and weight reduction in obese children., R. Pilcová, J. Šulcová, M. Hill, P. Bláha, L. Lisá., and Obsahuje bibliografii
Atherogenesis involves the migration of leukocytes into vascular subendothelial space, a process mediated by endothelial and leukocyte cell adhesion molecules. Endothelial molecules are assessed indirectly via serum levels, but leukocyte molecules can be assessed directly. We have therefore hypothesized that leukocyte adhesion molecules are altered to a greater degree in hypercholesterolemia than serum endothelial adhesion molecules. We examined 29 subjects with hypercholesterolemia and 27 controls at baseline and after 12 weeks of atorvastatin treatment (20 mg/day). Expression of leukocyte integrins CD11a, CD11b, CD18, and CD49d and of L-selectin was measured by flow cytometry. Serum ICAM-1, E-selectin and von Willebrand factor were measured by ELISA. Expression of leukocyte adhesion molecules was significantly higher in patients at baseline than in the controls, except for CD11a. Expression significantly decreased after atorvastatin in most adhesion molecules except for CD11b. In contrast, there was no effect of hypercholesterolemia and/or atorvastatin on the serum endothelial molecules. Leukocyte but not endothelial adhesion molecules were influenced by hypercholesterolemia and by lipid lowering treatment. Leukocyte molecules may therefore be a more sensitive marker of atherogenesis than endothelial molecules. Our results support the role of increased leukocyte adhesiveness in atherogenesis., T. Štulc, M. Vrablík, Z. Kasalová, I. Marinov, H. Svobodová, R. Češka., and Obsahuje bibliografii a bibliografické odkazy
In rats, the basic licking rhythm is generated by the central pattern generator located in the brainstem. Nevertheless, the licking frequency can be regulated between abou 7.5 and 4 Hz by changing the drinking conditions. If these conditions are kept constant, the licking frequency can be influenced only to a minor degree by factors such as deprivation level, type of solution, and phase of the session. The aim of our study was to compare the licking frequency of rats at different levels of vigilance. We investigated spontaneous licking of rats by an electrical lick sensor; parallel behavior monitoring was also performed. Animals kept in a stable environment and showing a lower level of vigilance licked at a rate of 5.96 Hz, fully vigilant rats licked significantly more rapidly at a frequency 6.57 Hz. The fastest rate of licking (6.49 Hz and 6.82 Hz, respectively) was encountered in alert rats under a mild stress caused by the presence of a second animal in the experimental box. The vigilance level is thus another factor affecting the licking rate of rats that should be taken into account in behavioral licking experiments., O. Vajnerová, E. Bielavská, P. Jiruška, G. Brožek., and Obsahuje bibliografii
The cyclical effects of hormones during the menstrual cycle (MC) are not just responsible for driving ovulation, but also have significant influence on dietary intake and appetite, as well as psychological and behavioral changes. The aim of our study was to describe changes and relationships between the MC and selected steroids, adipokines and food intake-related hormones. Twenty-seven women with regular menstrual cycles were included in the study, and their hormonal spectrum was measured in regular intervals starting from the first day of their cycle. Classical changes in gonadotropins, estrogens and progesterone during the menstrual cycle are accompanied by less striking but significant changes in 17-hydroxyprogesterone and testosterone. No significant changes show dehydroepiandrosterone and its 7-oxygenated metabolites. Adipokines show a tendency to increase during ovulation, while ghrelin and resistin decrease. There is also a remarkable association of sex hormone-binding globulin on the day of the cycle. Our results demonstrate that changes to adipokines during the menstrual cycle are not substantial, but nonetheless can play a role in the changes of food intake described in the literature. Precise descriptions of physiological changes in healthy women are important in helping us understand the significance of the changes accompanying various pathological states., M. Šrámková, M. Dušková, J. Vítků, J. Včelák, P. Matucha, O. Bradnová, J. de Cordeiro, L. Stárka., and Obsahuje bibliografii
The aim of this study was to determine the effect and mechanism of low concentration of lidocaine on subthreshold membrane potential oscillations (SMPO) and burst discharges in chronically compressed dorsal root ganglion (DRG) neurons. DRG neurons were isolated by enzymatic dissociation method. SMPO, burst discharges and single spike were elicited by whole cell patch-clamp technique in current clamp mode. Persistent Na+ current (INaP) and transient Na+ current (INaT) were elicited in voltage clamp mode. The results showed that SMPO was suppressed and burst discharges were eliminated by tetrodotoxin (TTX, 0.2 μ mol/l) in current clamp mode, INaP was blocked by 0.2 μ mol/l TTX in voltage clamp mode. SMPO, burst discharges and INaP were also suppressed by low concentration of lidocaine (10 μ mol/l) respectively. However, single spike and INaT could only be blocked by high concentration of lidocaine (5 mmol/l). From these results, it is suggested that INaP mediates the generation of SMPO in injured DRG neurons. Low concentration of lidocaine (10 μ mol/l) suppresses SMPO by selectively inhibiting INaP, but not INaT, in chronically compressed DRG neurons., H. Dong, Y.-H. Fan, Y.-Y. Wang, W.-T. Wang, S.J. Hu., and Obsahuje bibliografii a bibliografické odkazy
Previous studies have reported a decreased incidence of delayed graft function after cadaveric transplantation with the use of lidocaine pretreatment of the donor. We evaluated the effects of lidocaine on prolonged cold ischemia and reperfusion injury in a canine model of isolated kidney perfusion (IPK). The purpose of this study was to evaluate the renal function of isolated perfused canine kidneys after 48 h of cold storage with Euro-Collins (EC) solution or EC solution plus lidocaine. Isolated perfused canine kidneys were randomized into four groups which contained six kidneys: I) cold flush with EC solution and immediately reperfused, II) cold flush with EC solution plus lidocaine and immediately reperfused, III) 48 h of cold storage with EC and reperfusion, IV) 48 h of cold storage with EC solution plus lidocaine and reperfusion. The measured renal functions were glomerular filtration rate, urine production, perfusate flow, urinary lactic dehydrogenase (ULDH), Na reabsorptive capacity, and tissue MDA levels. Histological examination was performed after reperfusion. The tubular functions of kidneys preserved with EC solution containing lidocaine were better when compared with the kidneys preserved with EC alone. Tubular injury marker levels (ULDH) in group IV were significantly lower than in group III and lidocaine also reduced lipid peroxidation during reperfusion. This is in agreement with the histological results. The results of the present study can be taken as evidence of the cytoprotective effect of lidocaine, which may therefore be accepted as a useful agent for kidney preservation., N. Erkasap, E. Ates, S. Erkasap, Z. Kaygisiz., and Obsahuje bibliografii
During the early postnatal age environmental signals underlie the development of sensory systems. The visual system is considered as an appropriate system to evaluate role of sensory experience in postnatal development of sensory systems. This study was made to assess the effect of visual deprivation on strategy of arm selection in navigation of radial arm maze. Six-week-old light- (LR, control) and dark-reared (DR) rats were trained for correct choices and adjacent arms tasks. Our results showed that both the LR and DR animals equally selected correct arms. In the adjacent arms task, however, the control group significantly outperformed the DR animals. While the LR males and females displayed some differences in performing the tasks, no sex dependency was found in the performance of the DR group. These findings indicate that the lack of visual experience is likely to influence the strategy selection as well as sex differences. Thus the difference in the performance of LR and DR animals seems to be due to the male rather than female behavior., M. Salami., and Obsahuje bibliografii a bibliografické odkazy
Obesity is linked to a wide range of serious illnesses. In addition to the important impact on the health of the individual, obesity also has a substantial impact on the economy. Disruption of physiological day-night cycles could contribute to the increased incidence of obesity. According to the American National Sleep Federation, the percentage of the people who reported a sleep duration of six hours or less increased from 12 to 37 % over ten years. Insufficient sleep leads not only to an increase of the total calorie intake but changes the meal preference in favor of palatable foods and meals with high carbohydrate content. A decrease of leptin and increase of ghrelin levels caused by sleep deficiency can also play a role. In addition to the higher caloric intake, the timing of food consumption should be taken into account. The same meal eaten during the night versus the day is associated with increased postprandial glucose and triglyceride levels. The gut microbiome has also been recently understood as an endocrine system, with links between the gut microbiome and circadian rhythm changes possibly influencing increased obesity., B. Rácz, M. Dušková, L. Stárka, V. Hainer, M. Kunešová., and Obsahuje bibliografii
Lipasin is a recently identified lipokine expressed predominantly in liver and in adipose tissue. It was linked to insulin resistance in mice and to type 1 and type 2 diabetes (T1D, T2D) in humans. No metabolic studies concerning lipasin were performed yet in rats. Therefore, we used rat model of T2D and insulin resistance, Goto-Kakizaki (GK) rats, to determine changes of lipasin expression in liver and in white adipose tissue (WAT) over 52 weeks in the relation to glucose tolerance, peripheral tissue insulin sensitivity and adiposity. GK rats were grossly glucose intolerant since the age of 6 weeks and developed peripheral insulin resistance at the age of 20 weeks. Expression of lipasin in the liver did not differ between GK and Wistar rats, declining with age, and it was not related to hepatic triacylglycerol content. In WAT, the lipasin expression was significantly higher in Wistar rats where it correlated positively with adiposity. No such correlation was found in GK rats. In conclusion, lipasin expression was associated neither with a mild age-related insulin resistance (Wistar), nor with severe genetically-based insulin resistance (GK)., M. Cahová, D. Habart, T. Olejár, Z. Berková, Z. Papáčková, H. Daňková, A. Lodererova, M. Heczková, F. Saudek., and Obsahuje bibliografii