OBJECTIVEConditioned taste preference (CTP) is a taste learning reflex by which an animal learns to prefer a substance which tastes not well and has been studied with much interest in recent years. However, the neural substrates of CTP are less known. This study aimed to determine the possible neural path- ways of CTP and whether serum leptin level and the leptin receptor (OB-Rb) in the hind brain are involved following CTP formation.

METHODSWe established CTP of quinine in rats with a 2-bottle preference test. The serum leptin concentrations were detected, the expression of c-fos in the rat brain was tested to determine the nuclei in relation with establishment of CTR Finally, the OB-Rb mRNA expression was examined by RT-qPCR assay in parabrachial nucleus (PBN) and the nucleus of the solitary tract (NST) of the hind brain.

RESULTSCompared with control group, the level of serum leptin was higher in the CTP group (4.58 ± 0.52 vs 1.67 ± 0.25 µg/L, P < 0.01); increased c-fos positive cells were found in the anterior hypothalamus (AH, 221.75 ± 4.96 vs. 178.50 ± 6.63 cells/mm², P < 0.05), the basal lateral amygdala (BLA, 70.75 ± 6.17 vs 56.50 ± 3.62 cells/ mm², P < 0.05) and the nucleus of the solitary tract (NST, 41.25 ± 1.32 vs 32.50 ± 1.02 cells/mm², P < 0.05). But in ventromedial nucleus of the hypothalamus (VMH, 20.75 ± 2.73 vs 38.5 ± 1.54 per 1 mm², P < 005), PBN (21.50 ± 2.24 vs 36.25 ± 1.49 cells/mm², P < 0.05) and the central nucleus of the amygdala (CeA, 22.25 ± 1.53 vs 35.50 ± 2.11 cells/mm², P < 0.05), the number of c-fos positive cells was decreased in the CTP group. In addition, we found OB-Rb mRNA expression in PBN of CTP group rats was higher than that of control group (0.95 ± 0.055 vs 0.57 ± 0.034, P < 0.05), while there was no significant difference of OB-Rb mRNA expression in NST between the two groups.

CONCLUSIONNuclei AH, BLA, NST, VMH, PBN and CeA participate in the formation of CTP. Leptin and its receptor in PBN may be involved in the formation and maintenance of CTP.

Animals ; Conditioning (Psychology) ; Leptin ; blood ; Rats ; Receptors, Leptin ; physiology ; Rhombencephalon ; physiology ; Taste ; physiology

OBJECTIVETo observe effects of acupuncture on BMI, WHR and serum levels of leptin and neuropeptide Y in simple obesity Uigur patients to research the mechanism of acupuncture in slimming.

METHODSThirty simple obesity Uigur patients were treated with body acupuncture combined with electroacupuncture. Two courses later, their therapeutic effects were observed. And the above indexes were determined before and after treatment.

RESULTSThe clinical total effective rate was 80.00%, and BMI, WHR, and the serum leptin level decreased (P < 0. 001).

CONCLUSIONUigur patients of simple obesity possibly exist resistance of leptin and acupuncture can decrease the peripheral leptin content.

Acupuncture Therapy ; Electroacupuncture ; Humans ; Leptin ; blood ; Neuropeptide Y ; Obesity ; therapy

AIMTo determining whether the level of serum leptin altered and whether the expression of leptin receptor immunoreactivity changed following taste stimuli.

METHODSAfter intraoral infusions of chemical solutions, which included 3 mol/L sucrose, 5 mmol/L sodium saccharin, 0.1 mol/L NaCl, 0.01 mol/L HCl, 1 mmol/L quinine H2SO4 and 0.1 mol/L monosodium glutamate, serum leptin concentration were measured by using rat leptin RIA kit. Immunohistochemistry ABC method was used for brain sections with high-specify-goat antiserum against leptin receptors.

RESULTSComparing with the control group (intraoral infusion of distilled water), the level of serum leptin only in sweet group (sucrose an d saccharin) raised (P < 0.05). Many neuronal cell bodies and dendritic processes showed leptin receptors immunoreactivity (LR-IR) in many brain regions, such as amygdala, hypothalamus, parabrachial nucleus and nucleus of the solitary tract, which had intense relationship with taste and feeding. But the number of positive-stained cells showed no difference in aforementioned brain regions between the taste stimuli group and the control group.

CONCLUSIONAfter intraoral stimuli of sweet substances, the serum leptin concentration increased. LR-IR cells exist in amygdala which plays a critical role in the initiation and guidance of feeding. This findings led us study possible effects of leptin on taste responses. Probably, leptin influences food intake through the sense of taste.

Animals ; Brain ; physiology ; Eating ; Female ; Leptin ; blood ; metabolism ; Male ; Rats ; Rats, Sprague-Dawley ; Receptors, Leptin ; blood ; Taste

Animals ; Biomarkers ; blood ; Fatty Liver ; blood ; etiology ; Humans ; Leptin ; blood ; Obesity ; blood ; complications

OBJECTIVETo compare the slimming effects of electroacupuncture of different frequencies.

METHODSThe rats were randomly divided into a control group, a model group, an acupuncture group I (30 Hz), and an acupuncture group II (100 Hz). Acupoints selected were "Housanli" (ST 36), "Sanyinjiao" (SP 6), "Guanyuan" (CV 4), "Zhongwan" (CV 12). The changes of Lee's index, fat weight around the left kidney and the volume of the fat cell, blood lipids, insulin and leptin before and after treatment were compared.

RESULTSCompared with the model group, Lee's index, fat weight around the left kidney and the volume of the fat cell, blood lipids significantly changed in the two acupuncture groups (P<0.01), with the acupuncture group II being more change than that of the acupuncture group I (P<0.05); and compared with the model group, the leptin level decreased in the two acupuncture group (P<0.01) and the serum insulin level decreased (P<0.05) , with no significant difference between the acupuncture group I and the acupuncture group II (P>0.05).

CONCLUSIONElectroacupuncture of different frequencies has different effects on fat metabolism in fat rats, and electroacupuncture of 100 Hz has a better effect than 30 Hz on obesity.

Animals ; Electroacupuncture ; methods ; Insulin ; blood ; Leptin ; blood ; Lipids ; blood ; Obesity ; blood ; therapy ; Rats ; Rats, Sprague-Dawley

Adult ; Aged ; Anthracosis ; blood ; Humans ; Leptin ; blood ; Male ; Middle Aged ; Resistin ; blood

Adult ; Female ; Humans ; Leptin ; blood ; genetics ; Male ; Middle Aged ; Obesity ; blood ; RNA, Messenger ; blood

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

BACKGROUND/AIMS: Nonalcoholic fatty liver disease (NAFLD) comprises a large part of chronic liver diseases. Recently it was reported that adipokines are closely associated with the common risk factors for NAFLD, such as obesity, diabetes, dyslipidemia, and insulin resistance. We aimed to evaluate the changes in serum adiponectin, resistin and leptin concentrations related to alanine aminotransferase (ALT) elevations in Korean men with NAFLD. METHODS: We studies 38 men who were diagnosed with fatty liver by abdominal ultrasonography. None had a history of excessive alcohol consumption, autoimmune hepatitis, inherited or metabolic liver disease or viral hepatitis. The subjects were divided into two groups. One group had normal levels of ALT (n=28) and the other had increased ALT (n=10). We compared anthropometrical parameters, biochemical items and serum adipokine levels between these two groups. RESULTS: Serum adiponectin levels were lower in the increased ALT group than in the normal ALT group (3.89 +/- 1.77 vs 7.01 +/- 2.54 microgram/dL, P=0.001). But there were no significant differences in serum leptin and resistin levels between two groups (4.02 +/- 2.04 vs 3.26 +/- 1.41 ng/mL, p=0.245, 80.14 +/- 14.8 vs 80.5 +/- 11.34 ng/mL, P=0.937, respectively). Multiple linear regression analyses demonstrated that the serum adiponectin level is inversely correlated with serum ALT level and that the serum aspartate aminotransferase (AST) level is positively correlated with the serum ALT level. CONCLUSIONS: Our study shows that hypoadiponectinemia is associated with an ALT elevation in patients with NAFLD. Adiponectin may play an indirect role in the development of NAFLD.
Resistin/blood ; Middle Aged ; Male ; Leptin/blood ; Humans ; Fatty Liver/*blood ; Alanine Transaminase/*blood ; Aged ; Adiponectin/blood

OBJECTIVETo investigate the relationship between fasting serum levels of leptin, glucose, insulin resistance, lipids in simple obese children.

METHODSFasting serum levels of leptin and insulin (Fins) were measured by RIA in 42 obese and 42 normally-weighted children matched on age, sex and height, and their total cholesterol (TC), triglyceride (TG), high density lipoprotein-cholesterol (HDL-C) were analyzed with enzymatic methods. HOMA-IR and LDL-C were calculated.

RESULTSSerum level of leptin was (2.74 - 45.12) micro g/L and (0.53 - 10.18) micro g/L in obese and normally-weighted children, respectively, with an average level of leptin (log) significantly higher in obese group than that in control group (P < 0.001). Serum level of leptin was positively correlated with BMI, WHR and percentage of body fat. Of obese children, 83% were leptin resistant. Serum levels of TC, TG, LDL-C and insulin were significantly higher in obese leptin-resistant group than those in normally-weighted control group, but no significant difference in them between obese leptin-sensitive group and its normally-weighted control group was observed. Significantly higher serum levels of TG and lower HDL-C were observed in obese leptin-resistant group, as compared with those in obese leptin-sensitive group.

CONCLUSIONSA big difference in serum level of leptin between obese and normally-weighted children was found, suggesting most obese children were resistant to endogenous leptin. Leptin resistance correlated significantly with the risk of metabolic syndrome and cardiovascular disease, indicating serum level of leptin could be used as an indicator in screening obese children at high risk.

Blood Glucose ; metabolism ; Body Mass Index ; Child ; Cholesterol ; blood ; Female ; Humans ; Insulin Resistance ; Leptin ; blood ; Male ; Obesity ; blood ; Triglycerides ; blood