Animals ; Humans ; Leptin ; genetics ; physiology ; Liver Cirrhosis ; etiology ; RNA, Messenger ; analysis ; Receptors, Cell Surface ; analysis ; physiology ; Receptors, Leptin ; Transforming Growth Factor beta ; genetics ; Transforming Growth Factor beta1

OBJECTIVETo investigate serum leptin level and its relationship with bone mineral density in obese children from Changsha City.

METHODSOne hundred and nineteen obese children and 103 normal children aged 7 to 12 years from five primary schools of Changsha City were enrolled. Obesity was assessed based on the body mass index (BMI). Dual energy X-ray absorptiometry (DEXA) was used to determine bone mineral density (BMD) and body composition. Serum leptin level was measured using enzyme-linked immunosorbent assay (ELISA).

RESULTSThe obesity group had higher height, weight, BMI, waist circumference and waist to hip ratio (WHR) compared with the normal group (p<0.01). BMD, bone mineral content (BMC), lean mass (LM), fat mass (FM), percentage of body fat (%BF) and leptin concentration in the obesity group were significantly higher than those in the normal group (p<0.01). Serum leptin level was positively correlated with BMD, BMC, LM and FM (r=0.528-0.903, p<0.01). Multiple stepwise regression analysis indicated that BMI and %BF were independent influencing factors for serum leptin level.

CONCLUSIONSObese children have higher serum leptin level. Serum leptin concentration is significantly correlated with BMD and body composition. BMI and %BF are independent influencing factors for serum leptin level in children.

Body Composition ; Bone Density ; Child ; Female ; Humans ; Leptin ; blood ; Male ; Obesity ; blood ; Regression Analysis ; Sex Characteristics

OBJECTIVE: The primary aim of this study was to further characterize the acute effects of amitriptyline (AMI) and escitalopram (ESC) on serum levels of ghrelin, leptin, cortisol and prolactin in healthy humans. METHODS: Eleven healthy male participants received a single dose of AMI 75 mg, ESC 10 mg, or placebo (PLA) at 9:00 PM in a double blind, randomized, controlled, repeated measures study separated by one week. Fasting morning serum levels (7:00 AM) of ghrelin, leptin, cortisol and prolactin were assessed. RESULTS: A repeated measures multivariate analysis of variance revealed a significant main effect for the factor condition (AMI, ESC, PLA). Subsequent univariate analyses demonstrated significant condition effects for ghrelin and cortisol. Post-hoc analyses demonstrated a significant reduction of ghrelin levels after AMI in comparison to PLA, and a significant reduction of cortisol levels after AMI in comparison to both ESC and PLA. Other contrasts did not reach statistical significance. CONCLUSION: Administration of a single dose of AMI, but not of ESC, leads to a significant reduction in morning serum ghrelin and cortisol levels. No effects on leptin and prolactin levels were observed. The differential impact of AMI and ESC on hormones might contribute to different adverse effect profiles of both substances.
Amitriptyline* ; Citalopram* ; Fasting ; Ghrelin ; Healthy Volunteers* ; Humans ; Hydrocortisone ; Leptin ; Male ; Multivariate Analysis ; Prolactin ; Weight Gain

OBJECTIVETo evaluate the role of leptin in neointimal formation and related mechanisms.

METHODSFemoral arterial injury was induced in wild-type (Wt, n = 10), leptin-deficient (Lep(-)/-, n = 12), and leptin receptor-deficient (LepR(-)/-, n = 10) mice. Leptin treatment studies (tail vein injection of adenovirus expressing murine leptin on the RSV promoter, ad-leptin) were performed on Lep(-)/- (n = 5) and LepR(-)/- (n = 4) mice. Intimal (I) and medial (M) areas were measured and the ratio of I/M was calculated. Smooth muscle cells were detected by smooth muscle alpha-actin staining using an alpha-actin monoclonal antibody. Cellular proliferation was analyzed with BrdU Staining Kit and the number of BrdU-positive cells was counted manually. Plasma leptin level was measured by ELISA.

RESULTSThe I/M ratio of Lep(-)/- and LepR(-)/- mice was significantly lower than that in Wt separately (Lep(-)/- vs. Wt = 0.80 +/- 0.14 vs. 1.50 +/- 0.22, P < 0.01; LepR(-)/- vs. Wt = 0.55 +/- 0.20 vs. 1.50 +/- 0.22, P < 0.05). Plasma leptin level was significantly increased in Lep(-)/- and LepR(-)/- mice post leptin treatment. I/M was significantly increased in Lep(-)/- mice receiving ad-leptin compared with untreated Lep(-)/- mice (P < 0.05), while I/M was similar between LepR(-)/- mice with and without ad-leptin treatment (P > 0.05). The changes on number of positive alpha-actin and BrdU stained smooth muscle cells were consistent with the neointimal formation findings in various groups.

CONCLUSIONSMice lacking leptin or the leptin receptor were protected from neointimal formation following vascular injury. Leptin treatment increased neointimal formation in Lep(-)/- but not in LepR(-)/- mice, suggesting leptin receptor activation and vascular smooth muscle cell proliferation played a pivotal role on neointimal formation post-injury in this model, giving an evidence that high plasma leptin level is a risk factor for neointimal formation.

Actins ; analysis ; Animals ; Cell Proliferation ; Leptin ; blood ; Male ; Mice ; Mice, Inbred C57BL ; Mice, Knockout ; Muscle, Smooth, Vascular ; pathology ; Receptors, Leptin ; metabolism ; Tunica Intima ; pathology

OBJECTIVESome research has shown that C-reactive protein (CRP), leptin, soluble leptin receptor (sLR) and blood lipids are involved in the development of obesity. This study aimed to investigate the changes of leptin resistance, blood lipids and inflammatory response before and after the exercise therapy in children with obesity.

METHODSFifty-one obese children at ages of 12 years received an exercise therapy for 2 months. The levels of serum leptin, sLR, triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and high-sensitivity C-reactive protein (hs-CRP) were measured before and after the exercise therapy. Forty normal children served as the control group.

RESULTSCompared with the control group, serum levels of leptin, TG, TC, LDL-C and hs-CRP and the body mass index (BMI) in the obese group increased (p<0.01), while the serum level of sLR decreased significantly (p<0.05). The levels of hs-CRP, leptin, TC, TG, LDL-C and BMI in the obese group were significantly reduced after the exercise therapy (p<0.05). In the obese group, the serum leptin level was positively correlated with the levels of blood lipids and hs-CRP (p<0.05); serum levels of leptin and hs-CRP were negatively correlated with the sLR level (p<0.05); the hs-CRP level was positively correlated with the levels of blood lipids (p<0.01).

CONCLUSIONSLeptin resistance and the changes of blood lipids and inflammatory response are found in children with obesity. Exercise therapy can partially improve these changes.

Body Mass Index ; C-Reactive Protein ; analysis ; Child ; Exercise Therapy ; Female ; Humans ; Leptin ; blood ; Lipids ; blood ; Male ; Obesity ; blood ; therapy ; Receptors, Leptin ; blood

In order to explore the effect and underlying mechanism of hypoxia on body weight, the effect of intermittent moderate hypoxia on high-fat diet-induced obesity was observed in mice, and the role of leptin in hypoxic effect was identified. Healthy Kunming mice were divided randomly into 4 groups (n=20 in each group). The control group: the mice were fed normally under the normal oxygen pressure. Hypoxia group: the mice were fed normally, and given intermittent moderate hypoxia training. Obesity group: the mice were fed diet rich in fat and sugar under the normal oxygen pressure. Hypoxia + obesity group: the mice were fed diet rich in fat and sugar, and given intermittent moderate hypoxia training. After 40 d of feeding and training, the body weight of mice was determined, and the average increasing rate of body weight in each group was calculated and normalized with food intake. Meanwhile, plasma leptin level was measured with ELISA method, and fatty degeneration and leptin receptor expression in liver were observed by Sudan III staining and immunohistochemistry, respectively. The obesity mouse model was successfully established with increases in body weight, plasma leptin level and distribution of adipocytes in the liver. The average body weight and density of adipocytes in the liver in hypoxia and hypoxia + obesity groups decreased obviously, while plasma leptin level and leptin receptor expression in the liver were increased. It is suggested that intermittent moderate hypoxia reduces body weight through elevating plasma leptin level and/or enhancing leptin receptor expression in the liver.
Adipocytes ; cytology ; Animals ; Body Weight ; Female ; Hypoxia ; metabolism ; pathology ; Immunohistochemistry ; Leptin ; blood ; Liver ; chemistry ; Mice ; Mice, Obese ; Obesity ; metabolism ; pathology ; Receptors, Leptin ; analysis

OBJECTIVETo determine the changes in the expression of leptin and its receptor in the lungs of mice with varying degrees of asthma before and after budesonide treatment.

METHODSForty Balb/c mice were randomly assigned into 4 groups with 10 animals in each. One group received no treatment (control group) and the other groups were challenged with either nebulized ovalbumin (OVA) for three days (3-day group) or seven days (7-day group), or with nebulized ovalbumin followed by budesonide administration (treatment group). Changes in airway inflammation were observed using hematoxylin-eosin staining. The protein and mRNA levels of leptin and its receptor in lung tissues were determined using immunohistochemistry/Western blot and real-time PCR, respectively.

RESULTSThe two asthmatic groups showed more significant pathological changes in the airway than the control and the treatment groups. Mice that were challenged by OVA for seven days showed more marked pathological changes in the airway compared with mice challenged by OVA for three days. The protein and mRNA levels of leptin in the lung tissues of the 3-day group were significantly higher than those of the control group (P<0.01), but significantly lower than those of the 7-day group (P<0.01). The protein levels of leptin receptor in the lung tissues of the 3-day group were significantly lower than those of the control group (P<0.01). The treatment group showed increased protein levels of leptin receptor compared with the 7-day group (P<0.01). No significant difference was noted between the four groups with respect to the mRNA levels of leptin receptor in the lung tissues.

CONCLUSIONSLeptin is highly expressed whereas its receptor is lowly expressed in the lung tissues of asthmatic mice. Budesonide can increase the expression of leptin receptor, but has no significant impact on the expression of leptin.

Animals ; Asthma ; drug therapy ; metabolism ; pathology ; Blotting, Western ; Budesonide ; pharmacology ; Immunohistochemistry ; Leptin ; analysis ; genetics ; Lung ; chemistry ; pathology ; Male ; Mice ; Mice, Inbred BALB C ; RNA, Messenger ; analysis ; Receptors, Leptin ; analysis ; genetics

This study was performed to investigate the effect of peritoneal glucose load on plasma leptin concentrations in the continuous ambulatory peritoneal dialysis (CAPD) performed on 13 non-diabetic ESRD patients. Plasma leptin and insulin concentrations were measured for 2 hours during a single 2 liter exchange of 1.5% glucose-based dialysate (SPD, n = 6), for 7 days of daily peritoneal dialysis (DPD, n = 7). In DPD, standard full volume (2,000 ml x 4 times/day) exchange was performed immediately after operation. In SPD, plasma leptin and insulin concentrations remained unchanged during the study. In DPD, the plasma leptin concentration increased significantly after CAPD on the first day (PD1) (11.2 +/- 5.4 to 17.0 +/- 6.0 ng/mL, p < 0.05) and this elevation seemed to persist until 7 days after operation. After CAPD, there was no significant day-to-day variation in peritoneal glucose absorption (391-465 cal). Oral intake seemed to decrease on operation day (PD0) and PD1 and then increased slowly. Plasma insulin and glucose concentrations did not significantly change after CAPD. Changes of leptin concentration were significantly correlated with the changes of peritoneal glucose absorption at PD1. In conclusion, continuous peritoneal glucose load may affect plasma leptin concentrations in CAPD patients.
Adult ; Aged ; Female ; Glucose/metabolism* ; Human ; Leptin/analysis* ; Male ; Middle Age ; Peritoneal Dialysis, Continuous Ambulatory* ; Peritoneum/metabolism*

PURPOSE: Leptin is encoded by the ob gene and is involved in the control of food intake and energy expenditure. Recent studies have implicated leptin expression to be an indicator of tumor features and prognosis. The purpose of this study was to investigate the association of tissue expression of leptin with the clinicopathological characteristics and clinical outcomes in colorectal cancer patients. METHODS: Patients who had undergone a curative surgical resection for a colorectal adenocarcinoma from 2000 to 2004 were included in the study. Immunohistochemical analyses of leptin expression were performed, and clinicopathological parameters were evaluated. RESULTS: Clinical data and tumor tissues of 146 patients were evaluated. The mean age was 68.6 +/- 11.3 years, and 61.0% were men. Immunohistochemically, the rates of negative, weak, moderate, and strong leptin expression were 2.7% (4 of 146), 5.5% (8 of 146), 43.2% (63 of 146), and 48.6% (71 of 146), respectively. We compared the negative, weak, and moderate expression group (group A) with the strong expression group (group B). Leptin expression was inversely associated with nodal stage (P = 0.007) between the two groups. Leptin expression was not significantly associated with differentiation (P = 0.37), T stage (P = 0.16), and American Joint Committee on Cancer stage (P = 0.49), and no significant differences in the disease-free and the overall survivals (P = 0.78 and P = 0.61) were observed. CONCLUSION: Results demonstrated an inverse association of nodal stage with high leptin expression. Higher leptin expression level might predict better oncologic outcome. However, further studies are warranted to identify the exact role of leptin expression in colorectal cancer.
Adenocarcinoma ; Colorectal Neoplasms* ; Eating ; Energy Metabolism ; Humans ; Immunohistochemistry ; Joints ; Leptin* ; Male ; Prognosis ; Survival Rate ; Tissue Array Analysis

Adipose Tissue ; Animal Feed ; Animals ; Hypothalamus ; drug effects ; physiology ; Leptin ; pharmacology ; Male ; Mice ; Mice, Inbred Strains ; RNA ; analysis