Experimental study on the effect of An-pressing and Rou-kneading Huantiao (GB 30) on certain brain nuclei of pleasure circuits in rats with chronic neuralgia / 针灸推拿医学（英文版）

Objective:To explore the central neurobiological mechanisms of pleasure effect on rats with neuralgia treated by tuina manipulations of An-pressing and Rou-kneading Huantiao (GB 30).Methods:A total of 64 male Sprague-Dawley (SD) rats were used in this study.Eighteen rats were randomly selected as a normal group,and the other 46 rats were used to duplicate the chronic constriction injury (CCI) model.Ten rats failed in modeling and 36 rats succeeded.These 36 rats were then randomly divided into a model group and a tuina group,with 18 rats in each group.The rats in the normal group and the model group did not receive any interventions,while those in the tuina group received An-pressing and Rou-kneading Huantiao (GB 30),1 min for each time,once a day,3 weeks in total.Heating tests were evaluated to observe the change of pain-sensitivity score before intervention,1 week after intervention,2 weeks after intervention,and 3 weeks after intervention.After 1 week of intervention,2 weeks of intervention,and 3 weeks of intervention,6 rats were randomly selected from each group respectively for brain extraction.The change of Nissl's body and β-endorphin in the accumbens nucleus as well as amygdaloid nucleus of pleasure circuits,and pro-opiomelanocortin (POMC) in the arcuate nucleus were analyzed by methods of histochemistry and molecular biology.Results:After modeling,the pain-sensitivity scores of the tuina group and the model group were statistically different from the score of the normal group (both P＜0.05).After An-pressing and Rou-kneading Huantiao (GB 30) for one week,the pain-sensitivity score of the tuina group had statistical difference compared with that of the model group (P＜0.05).At each different time point:the amounts of Nissl's body in accumbens nucleus and amygdaloid nucleus of the tuina group were significantly more than those of the model group (all P＜0.01).Besides,the numbers of β-endorphin immunoreactive cells in the accumbens nucleus and amygdaloid nucleus of the rats in the tuina group were significantly higher than those in the model group (all P＜0.01),and so was the expression of POMC in arcuate nucleus (all P＜0.01).Conclusion:An-pressing and Rou-kneading Huantiao (GB 30),where the sciatic nerve is ligated,can reduce pain-sensitivity score and increase pain tolerance value of rats with chronic neuralgia.It can increase the activity of neurons in accumbens nucleus and amygdaloid nucleus of pleasure circuits,which indicates that the analgesia effect of tuina therapy may correlate with pleasure effect,and also reveals a part of neurobiological mechanisms of neuralgia.

Changes of ionized calcium binding adapter molecule 1 and pro-opiome-lanocortin expression in arcuate nucleus of hypothalamus induced by substantia nigra lesion with 6-hydroxydopamine / 中国病理生理杂志

AIM:To observe the expression of tyrosine hydroxylase (TH), ionized calcium binding adapter molecule 1 (Iba1) and pro-opiomelanocortin (POMC) in rat arcuate nucleus (Arc) of hypothalamus induced by substantia nigra (SN) lesion with 6-hydroxydopamine (6-OHDA).METHODS:According to the random number table, 20 SD rats were randomly divided into 6-OHDA group and control group.6-OHDA was injected into the bilateral SN of the rats in 6-OHDA group, and the same volume of saline was injected into the same position of the rats in control group.After 6 weeks, the rats were sacrificed and the brains were obtained.Immunofluorescence staining and Western blot were used to detect TH expression in the SN, and TH, Iba1 and POMC expression in the Arc.RESULTS:Compared with control group, no significant change of body weight in 6-OHDA group was observed, but the weight of retroperitoneal fat decreased from (7.550±0.670) g to (3.895±0.465) g (P<0.01).The number of TH immunoreactive neurons in SN decreased from 56±5 to 14±2 (P<0.05), and the TH protein level decreased from 0.75±0.11 to 0.41±0.09 (P<0.01).In the Arc, the number of TH immunoreactive neurons decreased from 21±2 to 10±3 (P<0.05), the number of Iba1 immunoreactive neurons increased from 12±2 to 30±5 (P<0.05), and the number of POMC immunoreactive neurons increased from 16±4 to 31±2 (P<0.05).In the hypothalamus, the TH protein level decreased from 0.35±0.05 to 0.21±0.02 (P<0.01), the Iba1 protein level increased from 0.23±0.06 to 0.51±0.04 (P<0.01), and the POMC protein level increased from 0.37±0.05 to 0.65±0.03 (P<0.01).CONCLUSION:The changes of TH, Iba1 and POMC expression in Arc of 6-OHDA-treated rats may involved in the fat loss in Parkinson's disease.

Reactive oxygen species signaling influences feeding behaviour.

Reactive Oxygen Species (ROS) are not just by products of substrate oxidation but also chemicals that are involved in intracellular signaling when they are generated transiently and moderately. This review explores the intracellular signaling aspects of reactive oxygen species in influencing feeding behaviour. Substrates like glucose and lipids stimulate generation of reactive oxygen species mainly through mitochondria and to some extent through the NADPH oxidases. The level of ROS generated in hypothalamic neurons like NPY/AgRP and POMC neurons, under the influence of substrate level, directly influences the activity of these neurons and subsequently affect the downstream neurons located in other parts of the hypothalamus like the ventromedial nucleus (VMN), the paraventricular nucleus (PVN) and the lateral hypothalamus. Activation of POMC neuronal population is driven by increase ROS level whereas activation of NPY/AgRP neurons occurs when ROS level is reduced. The activation of these neurons will determine the feeding behaviour which will either be satiety if POMC neurons are activated or increase food intake if NPY/AgRP neurons are activated.

Role of Reactive Oxygen Species in Hypothalamic Regulation of Energy Metabolism

To understand the etiology of metabolic disorders, including obesity and type II diabetes, it is essential to gain better insight into how stored and available energy sources are monitored by the central nervous system. In particular, a comprehension of the fine cellular interplay and intracellular mechanisms that enable appropriate hypothalamic and consequent endocrine and behavioral responses to both circulating hormonal and nutrient signals remains elusive. Recent data, including those from our laboratories, raised the notion that reactive oxygen species (ROS) generation is not merely a by-product of substrate oxidation, but it plays a crucial role in modulating cellular responses involved in the regulation of energy metabolism. These review summarizes the published recent data on the effect of ROS levels in the regulation of neuronal function, including that of hypothalamic melanocortin neurons, pro-opiomelanocortin and neuropeptide Y-/agouti related peptide-neurons, in the modulation of food intake.

Prevalence of RsaI Polymorphism in the 5’ Untranslated Region (UTR) of Proopiomelanocortin (POMC) Gene and its Association with Obesity in the Kampar Health Clinic Cohort, Malaysia

The pandemic of obesity is of great concern as its associated co-morbidities are devastating; causing lifelong burden to individual’s health and is economically costly to a country. Factors that lead to obesity are a combination of environmental and genetic factors. The Pro-opiomelanocortin (POMC) gene resides in chromosome 2p23.3, and its protein is composed of 241 amino acids which is responsible for the production of polyhormones that regulate appetite and food intake. The study aimed to investigate the prevalence of the RsaI single nucleotide polymorphism (SNP) site in the 5’-untranslated region (UTR) of POMC and its possible association with obesity among 302 multi-ethnic Malaysian subjects (142 obese, 160 non-obese; 120 males, 182 females) from the Kampar Health Clinic. Subjects were recruited by convenience sampling with informed consent and socio-demographic data as well as anthropometric measurements were taken. Subjects were genotyped by polymerase chain reaction - restriction fragment length polymorphism (PCR-RFLP) analysis using DNA extracted from blood. The distribution of the RsaI genotypes was significantly different among the different ethnicities, but the mutated RsaI (- / -) genotype was rare as it only occurred in 8.9% of the subjects. With the frequency of the RsaI (-) allele of 0.31, it was associated with the percentage of skeletal muscles (p<0.05), but not with obesity, gender, ethnicity and related anthropometric measurements. In conclusion, the 5’-UTR RsaI SNP in POMC may not be associated with obesity in the Kampar Health Clinic cohort; however, it could lead to the down-regulation of skeletal muscle build-up of up to 0.71%.

Intracerebroventricular Injection of Metformin Induces Anorexia in Rats

BACKGROUND: Metformin, an oral biguanide insulin-sensitizing agent, is well known to decrease appetite. Although there is evidence that metformin could affect the brain directly, the exact mechanism is not yet known. METHODS: To evaluate whether metformin induces anorexia via the hypothalamus, various concentrations of metformin were injected into the lateral ventricle of rats through a chronically implanted catheter and food intake was measured for 24 hours. The hypothalamic neuropeptides associated with regulation of food intake were also analyzed following 1 hour of intracerebroventricular (ICV) injections of metformin. RESULTS: An ICV injection of metformin decreased food intake in a dose-dependent manner in unrestrained conscious rats. Hypothalamic phosphorylated AMP-activated protein kinase (pAMPK) increased by 3 microg with metformin treatment, but there was no further increase in pAMPK with increases in metformin dosage. The hypothalamic phosphorylated signal transducer and activator of transcription 3 (pSTAT3) increased by 3 microg with metformin treatment, but, there was no further increase in pSTAT3 level following increases of metformin dosage. Hypothalamic proopiomelanocortin was elevated with metformin treatment, while neuropeptide Y was not significantly changed. CONCLUSION: Our results suggest that metformin induces anorexia via direct action in the hypothalamus and the increase in pSTAT3, at least in part, is involved in the process. However, hypothalamic pAMPK appears not to contribute to metformin-induced appetite reduction in normal rats. Further studies exploring new pathways connecting metformin and feeding regulation are needed.

Effect of Geranium Essential Oil on Food Intake via Olfactory Stimulus / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Recently, obesity has become one of the major health problems in our society. To overcome this problem, keeping a balance between food intake and energy expenditure is very important. Many natural substances including essential oils have been suggested for their potential effect on reducing weight. This study was performed to evaluate whether aroma inhalation of essential oil has a role in appetite regulation and works on the central nervous system through the olfactory stimulus. MATERIALS AND METHOD: Food intake was measured after 30 minutes of treatment with essential oil in overnight fasted Sprague-Dawley rats. In the control group, saline was used instead of essential oil. Changes in pro-opiomelanocortin (POMC) and neuropeptide Y (NPY) mRNA expression levels in the hypothalamus were measured following 30 minutes of treatment with geranium essential oil using real-time polymerase chain reaction. RESULTS: Of the seven essential oils, geranium significantly decreased the amount of food intake compared to the control group. Geranium essential oil significantly increased POMC mRNA expression in the hypothalamus, but did not change the NPY mRNA expression. The increased POMC mRNA expression was reversed by treatment with xylocaine, which blocks the olfactory perception. CONCLUSION: These results suggest that geranium essential oil has anorexic effect through the activation of POMC neurons in the hypothalamus via olfactory stimulus.

Associação de POMC, NPY e IRS2 hipotalâmicos com padrões de comportamento alimentar em ratos Wistar normais e sobrepeso / Association of POMC, NPY and hypothalamic IRS2 with patterns of eating behavior in overweight and normal Wistar rats

O comportamento alimentar de uma espécie é determinado por um conjunto de características filogenéticas, ontogenéticas, e epigenéticas, e regulado por fatores internos e externos ao organismo. Os fenômenos naturais que regem a vida no nosso planeta são periódicos em sua maioria, e a oferta de alimentos não é exceção. Cada safra é seguida de uma entressafra, e este ritmo sincroniza diversos outros ritmos, exógenos e endógenos, capazes de determinar a sobrevivência de espécies. Uma das estratégias adaptativas mais primitivas e bem sucedidas na dinâmica oscilatória da natureza, é o acúmulo de reservas. Nossa espécie, nos últimos 50 anos, vive uma situação de grande oferta de alimentos, período este extremamente pequeno, se visto sob a ordem de grandeza da evolução humana. Este fenômeno tem sido determinante na prevalência do depósito de energia e em decorrência, do surgimento da obesidade e suas consequentes patologias. O hipotálamo está intimamente associado à homeostase energética e ao comportamento alimentar. No núcleo arqueado hipotalâmico encontram-se populações neuronais orexigênicas e anorexigênicas, dentre as quais, as que expressam os neuroreceptores POMC, NPY e o substrato de receptor de insulina IRS2. A modificação da expressão destas proteínas tem sido associada à alterações do comportamento alimentar, bem como à impressão e programação metabólica, capazes de induzir obesidade em ratos adultos. A correlação desta circuitaria neuronal com o comportamento alimentar, porém, ainda não está suficientemente compreendida. A detecção do estado de fome-saciedade nos ratos, fundamental no estudo da neurofisiologia relacionada ao comportamento alimentar, vem sendo obtida via de regra, por meio de procedimentos complexos de observação comportamental. O presente estudo contribui para o conhecimento de padrões de alimentação determinados por condições nutricionais, e sua relação com a expressão neurofisiológica hipotalâmica dos neurônios POMC, NPY e IRS2 ...

The feeding behavior of a specie is determined by a group of phylogenetic, ontogenetic, and epigenetic features, and regulated by internal and external factors to the organism. The natura phenomena that govern life in our planet are mainly periodic, and the food stocks is not an exception. Each harvest is followed by a time between harvests, and this rhythm synchronizes other several exogenous and endogenous rhythms, capable of determining the survival of species. One of the most primitive strategies of adaptative evolution of species, and what usually happens regarding the oscillatory dynamics of nature, is the reserve accumulation. Our species, in the last 50 years, has been living a situation of great food offer, such period is exremely small if analysed under the greatness order of the human evolution. This phenomenon has been decisive in the prevalence of the energy deposit and, in consequence, determining the appearance of obesity and its consequent pathologies. The hypothalamus is intimately associated to the energy homeostasis and the feeding behavior. In the arcuate nucleous are orexigenic and anorexigenic neuronal populations, that express the neuroreceptors POMC, NPY and insulin receptor substratum IRS2. The modification of these proteins expression, has been associated to alterations of the feeding behavior, as well as to the metabolic imprinting and programming, capable to induce obesity in adult rats. The correlation of this neuronal circuits with the alimentary behavior, however, it is not yet sufficiently understood. The detection of the hunger-satiation state in the rat, crucial in the neurophysiology studies related to the alimentary behavior, has been obtained through complex procedures of behavioral observation. The present study contributed to the knowledge of certain feeding patterns for nutritional conditions, and its relationship with the neurophysiological expression of POMC, NPY and IRS2 neurons. Using the metabolic programming ...

Programação do processo fome-saciedade de animais desnutridos no início da lactação: papel do NPY/AgRP e POMC / Programming hunger-satiety process of malnourished animals in early lactation: role of NPY/AgRP and POMC

A modulação do processo fome-saciedade é um fator determinante para o crescimento normal dos sistemas metabólicos. Tem sido demonstrado que variações nutricionais nos períodos pré e pós-natal induzem modificações nas projeções e/ou contatos dos circuitos neuronais hipotalâmicos, gerando uma "reprogramação" deste sistema que envolve mecanismos de interação da ação primária de hormônios como leptina em neurônios orexigênico (NPY/AgRP) anorexigênicos (POMC) no núcleo arqueado, para regular o comportamento alimentar. O objetivo deste trabalho foi estudar a programação do processo fome-saciedade no núcleo arqueado hipotalâmico, em curto e longo prazos, em animais que foram desnutridos no início da lactação. Para isso, utilizamos ratos Wister desnutridos nos primeiros 10 dias de lactação com a utilização de dieta materna com 0% de proteína e que foram submetidos a novo período de desnutrição protéica na fase adulta (60 dias de idade) por 3 dias. Para o estudo do processo fome-saciedade, as variáveis avaliadas foram peso corporal, razão peso corporal / consumo alimentar, conteúdos de receptores de leptina (Ob-Rb) e de neuropeptídeos hipotalâmicos (NPY/AgRP e POMC). Observamos que ao final de 10 dias de desnutrição na lactação, os animais desnutridos apresentaram menor peso corporal (FD - fêmea desnutrida, 50% e MD - macho desnutrido, 53%) e aumento dos conteúdos de Ob-Rb (FD: 121,67% e MD: 132,73%), NPY/AgRP (FD: 32,31% e MD: 115,62%) e POMC (FD: 71,2% e MD: 26,58%). Aos 60 dias de vida, os animais desnutridos apresentaram maior razão peso corporal / consumo alimentar e não evidenciamos diferença nos conteúdos de Ob-Rb, NPY/AgRP e POMC (p<-0,05). Aos 63 dias de vida, fêmeas (FDD) e machos desnutridos (MDD), após um segundo episódio de desnutrição, apresentaram redução de peso corporal (FDD: 12,4% e MDD: 10,75%) e consumo alimentar (FDD: 57,5% e MDD: 39,88%). O conteúdo dos neuropeptídeos orexigênicos (NPY/AgRP)...

The modulation of the hunger-satiety process is a determining factor for the normal growth of the metabolic systems. It has been demonstrated that nutritional variations during pre- and postnatal lead to modifications in projetions and/or contacts of hypothalamic neuronal circuits generating a "reprogramation" of this system, which involves mechanisms of interation of primary action of hormone as leptin in NPY/AgRP and POMC neurons in the arcuate nucleus, to regulate eating behavior. Our aim was to study the programation in the hunger-satiety process in the arcuate nucleus, in the short and long terms, in animals that were malnourished during the early lactation period. In the present study we used Wistar rats that were malnourished during the first 10 days of lactation (0% protein maternal diet) and that were submitted to new a period of malnutrition at adulthood (60 days-old) for 3 days. To study the hunger-satiety process, the variables evaluated were: body weight, body weight/food intake ratio, hypothalamic content of the leptin receptor (Ob-Rb) and the orexigenic NPY/AgRP and anorexigenic POMC neuropeptides. We observed at the end of 10 days of malnutrition during lactation, that the malnourished animals had lower body weight (MF - malnourished female, 50% and MM - malnourished male, 53%) and higher content of Ob-Rb (MF: 121,67% and MM: 132,73%), NPY/AgRP (MF: 32,31% e MM: 115,62%) and POMC (MF: 71,2% e MM: 26,58%). At 60 days, the malnourished animals had higher body weight/food intake ratio and showed no change in the Ob-Rb, NPY/AgRP and POMC content (p<-0,05). At 63 days of life, malnourished female and male after a second episode of malnutrition, had lower body weight (MMF: 12,4% and MMM: 10,75%) and food intake (MMF: 57,5% and MMM: 39,88%). The content of neuropeptides (NPY/AgRP) was significantly lower (MMF: 22,6% and MMM: 26,58%), while the content of Ob-Rb (MMF: 92,27% and MMM: 28%) and POMC neuropeptide (MMF: 22,34% and MMM:27,27%)...