RESUMO
The gut microbiota affects the host's metabolic phenotype, impacting health and disease. The gut-brain axis unites the intestine with the centers of hunger and satiety, affecting the eating behavior. Deregulation of this axis can lead to obesity onset. Litter size reduction is a well-studied model for infant obesity because it causes overnutrition and programs for obesity. We hypothesize that animals raised in small litters (SL) have altered circuitry between the intestine and brain, causing hyperphagia. We investigated vagus nerve activity, the expression of c-Fos, brain-derived neurotrophic factor (BDNF), gastrointestinal (GI) hormone receptors, and content of bacterial phyla and short-chain fatty acids (SCFAs) in the feces of adult male and female Wistar rats overfed during lactation. On the 3rd day after birth, litter size was reduced to 3 pups/litter (SL males or SL females) until weaning. Controls had normal litter size (10 pups/litter: 5 males and 5 females). The rats were killed at 5 months of age. The male and female offspring were analyzed separately. The SL group of both sexes showed higher food consumption and body adiposity than the respective controls. SL animals presented dysbiosis (increased Firmicutes, decreased Bacteroidetes) and had increased vagus nerve activity. Only the SL males had decreased hypothalamic GLP-1 receptor expression, while only the SL females had lower acetate and propionate in the feces and higher CCK receptor expression in the hypothalamus. Thus, overfeeding during lactation differentially changes the gut-brain axis, contributing to hyperphagia of the offspring of both sexes.
Assuntos
Eixo Encéfalo-Intestino , Hiperfagia/microbiologia , Tamanho da Ninhada de Vivíparos , Adiposidade , Animais , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Feminino , Peptídeo 1 Semelhante ao Glucagon/metabolismo , Hiperfagia/metabolismo , Hiperfagia/fisiopatologia , Hipotálamo/metabolismo , Hipotálamo/fisiologia , Masculino , Proteínas Proto-Oncogênicas c-fos/metabolismo , Ratos , Ratos Wistar , Receptores da Colecistocinina/metabolismo , Nervo Vago/metabolismo , Nervo Vago/fisiologiaRESUMO
Cholecystokinin (CCK), the most abundant brain neuropeptide, is involved in relevant behavioral functions like memory, cognition, and reward through its interactions with the opioid and dopaminergic systems in the limbic system. CCK excites neurons by binding two receptors, CCK1 and CCK2, expressed at low and high levels in the brain, respectively. Historically, CCK2 receptors have been related to the induction of panic attacks in humans. Disturbances in brain CCK expression also underlie the physiopathology of schizophrenia, which is attributed to the modulation by CCK1 receptors of the dopamine flux in the basal striatum. Despite this evidence, neither CCK2 receptor antagonists ameliorate human anxiety nor CCK agonists have consistently shown neuroleptic effects in clinical trials. A neglected aspect of the function of brain CCK is its neuromodulatory role in mental disorders. Interestingly, CCK is expressed in pivotal inhibitory interneurons that sculpt cortical dynamics and the flux of nerve impulses across corticolimbic areas and the excitatory projections to mesolimbic pathways. At the basal striatum, CCK modulates the excitability of glutamate, the release of inhibitory GABA, and the discharge of dopamine. Here we focus on how CCK may reduce rather than trigger anxiety by regulating its cognitive component. Adequate levels of CCK release in the basal striatum may control the interplay between cognition and reward circuitry, which is critical in schizophrenia. Hence, it is proposed that disturbances in the excitatory/ inhibitory interplay modulated by CCK may contribute to the imbalanced interaction between corticolimbic and mesolimbic neural activity found in anxiety and schizophrenia.
Assuntos
Ansiedade , Colecistocinina , Esquizofrenia , Humanos , Receptor de Colecistocinina B , Receptores da ColecistocininaRESUMO
OBJECTIVE: This study evaluated the effect of a protein, the isolated Trypsin Inhibitor (TTI) from Tamarindus indica L. seed, as a CCK secretagogue and its action upon food intake and leptin in obese Wistar rats. METHODS: Three groups of obese rats were fed 10 days one of the following diets: Standard diet (Labina®) + water; High Glycemic Index and Load (HGLI) diet + water or HGLI diet + TTI. Lean animals were fed the standard diet for the 10 days. Food intake, zoometric measurements, plasma CCK, plasma leptin, relative mRNA expression of intestinal CCK-related genes, and expression of the ob gene in subcutaneous adipose tissue were assessed. RESULTS: TTI decreased food intake but did not increase plasma CCK in obese animals. On the other hand, TTI treatment decreased CCK-1R gene expression in obese animals compared with the obese group with no treatment (p = 0.027). Obese animals treated with TTI presented lower plasma leptin than the non-treated obese animals. CONCLUSION: We suggest that TTI by decreasing plasma leptin may improve CCK action, regardless of its increase in plasma from obese rats, since food intake was lowest.
Assuntos
Depressores do Apetite/farmacologia , Ingestão de Alimentos/efeitos dos fármacos , Leptina/sangue , Obesidade , Proteínas de Vegetais Comestíveis/farmacologia , Receptores da Colecistocinina/genética , Tamarindus/química , Animais , Depressores do Apetite/isolamento & purificação , Depressores do Apetite/uso terapêutico , Regulação para Baixo/efeitos dos fármacos , Expressão Gênica/efeitos dos fármacos , Masculino , Obesidade/sangue , Obesidade/tratamento farmacológico , Obesidade/genética , Proteínas de Vegetais Comestíveis/isolamento & purificação , Ratos , Ratos Wistar , Receptores da Colecistocinina/metabolismo , Resposta de Saciedade/efeitos dos fármacos , Sementes/químicaRESUMO
The purpose of this study was to assess the effect of the non-selective cholecystokinin receptor antagonist proglumide on the antinociceptive activity of ketorolac and meloxicam in non-diabetic and diabetic rats. Streptozotocin (60 mg/kg) injection caused hyperglycemia which was maintained for 2 weeks. Formalin-evoked flinching was increased in diabetic rats as compared to non-diabetic rats. Local peripheral ipsilateral, but not contralateral, administration of ketorolac and meloxicam produced antinociception in non-diabetic and diabetic rats. However, the antinociceptive effect of both drugs was significantly reduced in diabetic animals. Proglumide was ineffective by itself and it did not affect the antinociception induced by the cyclooxygenase inhibitors in non-diabetic rats. Contrariwise, proglumide reduced formalin-induced nociception and it increased ketorolac- or meloxicam-induced antinociception in diabetic rats. These results suggest that peripheral cholecystokinin plays an important role in diabetes-induced sensitization as well as in the reduction of the antinociceptive effects of ketorolac and meloxicam in diabetic rats. The combination of cholecystokinin receptor antagonists and ketorolac or meloxicam may be a useful strategy to reduce nociception in diabetic patients.
Assuntos
Analgésicos/farmacologia , Inibidores de Ciclo-Oxigenase/farmacologia , Diabetes Mellitus Experimental/fisiopatologia , Formaldeído/efeitos adversos , Proglumida/farmacologia , Prostaglandina-Endoperóxido Sintases/metabolismo , Animais , Anti-Inflamatórios não Esteroides/farmacologia , Comportamento Animal/efeitos dos fármacos , Sinergismo Farmacológico , Cetorolaco/farmacologia , Masculino , Meloxicam , Ratos , Ratos Wistar , Receptores da Colecistocinina/antagonistas & inibidores , Tiazinas/farmacologia , Tiazóis/farmacologiaRESUMO
This work analyzes the role of cholecystokinin (CCK) receptors, dynorphin A1â17 and descending facilitation originated in the rostral ventromedial medulla (RVM) on secondary allodynia and hyperalgesia in formalin-injected rats. Formalin injection (50 µL, 1%, s.c.) produced acute nociception (lasting 1 h) and long-term secondary allodynia and hyperalgesia in ipsilateral and contralateral hind paws (lasting 1-12 days). Once established, intra-RVM administration of lidocaine at day 6, but not at 2, reversed secondary allodynia and hyperalgesia in rats. The injection of YM022 (CCK2 receptor antagonist), but not lorglumide (CCK1 receptor antagonist), into the RVM or spinal cord reversed both nociceptive behaviors. Pre-treatment with lidocaine, lorglumide or YM022 did not prevent the development of secondary allodynia or hyperalgesia regardless of the administration route. Formalin injection increased dynorphin content in the dorsal, but not the ventral, spinal cord sections at day 6. Moreover, intrathecal administration of dynorphin antiserum reversed, but was unable to prevent, secondary allodynia and hyperalgesia in both hind paws. These results suggest that formalin-induced secondary allodynia and hyperalgesia are maintained by activation of descending facilitatory mechanisms which are dependent on CCK2 receptors located in the RVM and spinal cord. In addition, data suggest that spinal dynorphin A1â17 and CCK play an important role in formalin-induced secondary allodynia and hyperalgesia.
Assuntos
Formaldeído/farmacologia , Hiperalgesia/induzido quimicamente , Receptores da Colecistocinina/fisiologia , Animais , Dinorfinas/metabolismo , Feminino , Soros Imunes , Bulbo/efeitos dos fármacos , Bulbo/fisiopatologia , Ratos , Ratos Wistar , Medula Espinal/metabolismoRESUMO
Cholecystokinin (CCK) influences gastrointestinal motility, by acting on central and peripheral receptors. The aim of the present study was to determine whether CCK has any effect on isolated duodenum longitudinal muscle activity and to characterize the mechanisms involved. Isolated segments of the rat proximal duodenum were mounted for the recording of isometric contractions of longitudinal muscle in the presence of atropine and guanethidine. CCK-8S (EC50: 39; 95% CI: 4.1-152 nM) and cerulein (EC50: 58; 95% CI: 18-281 nM) induced a concentration-dependent and tetrodotoxin-sensitive relaxation. Nomeganitro-L-arginine (L-NOARG) reduced CCK-8S- and cerulein-induced relaxation (IC50: 5.2; 95% CI: 2.5-18 microM) in a concentration-dependent manner. The magnitude of 300 nM CCK-8S-induced relaxation was reduced by 100 microM L-NOARG from 73 +/- 5.1 to 19 +/- 3.5% in an L-arginine but not D-arginine preventable manner. The CCK-1 receptor antagonists proglumide, lorglumide and devazepide, but not the CCK-2 receptor antagonist L-365,260, antagonized CCK-8S-induced relaxation in a concentration-dependent manner. These findings suggest that CCK-8S and cerulein activate intrinsic nitrergic nerves acting on CCK-1 receptors in order to cause relaxation of the rat duodenum longitudinal muscle.
Assuntos
Ceruletídeo/farmacologia , Colecistocinina/farmacologia , Duodeno/efeitos dos fármacos , Contração Muscular/efeitos dos fármacos , Óxido Nítrico Sintase/antagonistas & inibidores , Fragmentos de Peptídeos/farmacologia , Receptores da Colecistocinina/fisiologia , Animais , Relação Dose-Resposta a Droga , Duodeno/fisiologia , Masculino , Ratos , Ratos WistarRESUMO
Cholecystokinin (CCK) influences gastrointestinal motility, by acting on central and peripheral receptors. The aim of the present study was to determine whether CCK has any effect on isolated duodenum longitudinal muscle activity and to characterize the mechanisms involved. Isolated segments of the rat proximal duodenum were mounted for the recording of isometric contractions of longitudinal muscle in the presence of atropine and guanethidine. CCK-8S (EC50: 39; 95 percent CI: 4.1-152 nM) and cerulein (EC50: 58; 95 percent CI: 18-281 nM) induced a concentration-dependent and tetrodotoxin-sensitive relaxation. Nomeganitro-L-arginine (L-NOARG) reduced CCK-8S- and cerulein-induced relaxation (IC50: 5.2; 95 percent CI: 2.5-18 æM) in a concentration-dependent manner. The magnitude of 300 nM CCK-8S-induced relaxation was reduced by 100 æM L-NOARG from 73 ± 5.1 to 19 ± 3.5 percent in an L-arginine but not D-arginine preventable manner. The CCK-1 receptor antagonists proglumide, lorglumide and devazepide, but not the CCK-2 receptor antagonist L-365,260, antagonized CCK-8S-induced relaxation in a concentration-dependent manner. These findings suggest that CCK-8S and cerulein activate intrinsic nitrergic nerves acting on CCK-1 receptors in order to cause relaxation of the rat duodenum longitudinal muscle.
Assuntos
Animais , Masculino , Ratos , Ceruletídeo/farmacologia , Colecistocinina/farmacologia , Duodeno/efeitos dos fármacos , Contração Muscular/efeitos dos fármacos , Óxido Nítrico Sintase/antagonistas & inibidores , Fragmentos de Peptídeos/farmacologia , Receptores da Colecistocinina/fisiologia , Relação Dose-Resposta a Droga , Duodeno/fisiologia , Ratos WistarRESUMO
The etiology of functional dyspepsia is not known. The objective of the present study was to determine the characteristics of functional dyspepsia in Western Turkey. We divided 900 patients with functional dyspepsia into three subgroups according to symptoms: ulcer-like (UL), 321 (35.6 percent), motility disorder-like (ML), 281 (31.2 percent), and the combination (C) of these symptoms, 298 (33.1 percent). All patients were submitted to endoscopic evaluation, with two biopsies taken from the cardia and corpus, and four from the antrum of the stomach. All biopsy samples were studied for Helicobacter pylori (Hp) density, chronic inflammation, activity, intestinal metaplasia, atrophy, and the presence of lymphoid aggregates by histological examination. One antral biopsy was used for the rapid urease test. Tissue cagA status was determined by PCR from an antral biopsy specimen by a random sampling method. We also determined the serum levels of tumor necrosis factor-alpha (TNF-alpha) and gastrin by the same method. Data were analyzed statistically by the Kolmogorov-Smirnov test and by analysis of variance. Hp and cagA positivity was significantly higher in the UL subgroup than in the others. The patients in the ML subgroup had the lowest Hp and cagA positivity and Hp density. The ML subgroup also showed the lowest level of Hp-induced inflammation among all subgroups. The serum levels of TNF-alpha and gastrin did not reveal any difference between groups. Our findings show a poor association of Hp with the ML subgroup of functional dyspepsia, but a stronger association with the UL and C subgroups
Assuntos
Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Dispepsia , Infecções por Helicobacter , Helicobacter pylori , Análise de Variância , Dispepsia , Gastrinas , Infecções por Helicobacter , Reação em Cadeia da Polimerase , Receptores da Colecistocinina , Estatísticas não Paramétricas , Fator de Necrose Tumoral alfa , TurquiaRESUMO
In rats, the nematode Nippostrongylus brasiliensis induces an intestinal inflammation, but after the inflammation had resolved and the worm burden eliminated, morphological alterations of the intestinal wall, mainly consisting of mast cell hyperplasia and enteric nerve remodeling, persist for several weeks. Intestinal signals reaching the brain through the vagus nerve and involving neuropeptides such as CCK, play a role in the control of food intake. Our hypothesis was that neuroimmune alterations of the intestine may alter this control. This work was aimed to evaluate whether post-infection alterations of the intestinal wall may affect the satiety effects of CCK and further, the role of mast cells and their mediators, histamine and serotonin, in post-N. brasiliensis-infected rats. In basal conditions, food intake was not different in control and post-infected groups of rats. Post-infected rats were characterized by prolonged satiety effects of both CCK and histamine but not serotonin. The prolonged effect of CCK was reduced when mast cells were previously stabilized by ketotifen, which had no effect per se on food intake. No difference was observed in the increase of food intake induced by CCK-A and CCK-B receptor antagonists in both control and post-infected rats. Mast cell degranulation with compound 48/80 induced severe anorectic effects that lasted for less than 24h in post-infected rats and as long as 6 days in controls. Thus, in our experimental conditions, i.e., within 30-50 days post-N. brasiliensis infection, we observed an enhancement of the anorectic effect of exogenous CCK involving mast cell degranulation and histamine.
Assuntos
Colecistocinina/farmacologia , Nippostrongylus , Resposta de Saciedade/efeitos dos fármacos , Infecções por Strongylida/fisiopatologia , Animais , Benzodiazepinonas/farmacologia , Degranulação Celular/fisiologia , Devazepida/farmacologia , Ingestão de Alimentos/efeitos dos fármacos , Histamina/farmacologia , Antagonistas dos Receptores Histamínicos H1/farmacologia , Antagonistas de Hormônios/farmacologia , Cetotifeno/farmacologia , Masculino , Mastócitos/fisiologia , Compostos de Fenilureia/farmacologia , Ratos , Ratos Wistar , Receptores da Colecistocinina/antagonistas & inibidores , Serotonina/farmacologiaRESUMO
Blockade of cholecystokinin (CCK) receptors potentiates the morphine-induced disruption of maternal behavior. The present study was undertaken to determine whether treatment with lorglumide, a CCK1 antagonist during late pregnancy and early lactation can influence the maternal behavior during lactation. A possible influence of this treatment on general activity was also assessed. Twenty-seven female Wistar rats were pretreated with lorglumide (1.0mg/kg/day; sc) or saline for seven days, starting on the 17th d of pregnancy. After the withdrawal of this treatment, animals were acutely challenged with saline on day 5 and with morphine sulfate (3.0mg/kg; sc) on days 6,10, and 17 of lactation. Groups were pretreated with saline and challenged with saline (group SS) and morphine (group SM), pretreated with lorglumide and challenged with saline (group LS) and morphine (group LM). Animals were also tested for general activity on days 25 and 33 postpartum after an acute challenge with saline and morphine, respectively. Maternal behavior testing began 30 min after the acute injections at which time pups were placed throughout each mother's cage. Latencies for pup retrieval, grouping, crouching and for full maternal behavior responses were scored. Lorglumide pretreatment inhibited maternal behavior of LS vs SS group and potentiated the morphine-induced disruption of this behavior in all days of test (LM vs SM group). No significant differences were found in general activity on days 25 and 33 postpartum. These data suggest that blockade of CCK1 receptors during puerperal period has long-term implications for maternal behavior.