[Abnormal expression of Wnt3a and inhibiting role of its molecular-targeted intervening in hepatocellular carcinoma].

Objective: To investigate the Wnt3a expression in tissues of HCC and its gene knockout on effects of HepG2 cell proliferation or xenograft tumor growth. Methods: Hepatic Wnt3a expressions in 87 HCC and their matched surrounding tissues were observed by tissue microarray and immunohistochemistry for analyzing its clinicopathological characteristics; Wnt3a-knockout HepG2 cell lines were established by Crispr/cas9-sgRNA system and genomic cleavage efficiency was verified at gene level by surveyor assay. The relative proteins were confirmed by Western blotting; Cell Counting Kit-8 assay was used to examine cell proliferation after knocking-out Wnt3a successfully, and the nude mice HepG2 cell xenograft tumors delete that the relationship between Wnt3a and HCC growth. Results: The positive Wnt3a with brown staining particles was mainly distributed in cytosol and membrane of hepatocytes. The incidence of hepatic Wnt3a expression in cancerous tissues (95.4%) was significantly higher (χ (2) = 47.754, P < 0.001) than that in their surrounding tissues (49.4%). The high Wnt3a expression was 70.1% in the HCC and only 14.9% in the surrounding tissues. High Wnt3a expression was associated with poorly-differentiated grade, liver cirrhosis, HBV infection, portal vein invasion, TNM stage and 5-year survival rate. After knocked-out by Crispr/cas9-sgRNA system successfully, Wnt3a expression was down-regulated significantly at gene or protein level. Key molecule ß-catenin in cytoplasma was obviously inhibited. HepG2 cell lines proliferation was suppressed in time-dependent manner. The nude mice HepG2 cell xenograft tumors confirmed that the knock-out of Wnt3a could significantly supressed HCC growth with slower speed (t = 6.418, P < 0.001), smaller volume(869.4 ± 222.5 mm(3) vs 355.0 ± 99.9 mm(3), t = 5.168, P < 0.001), and lighter weight (0.88 ± 0.20 g vs 0.35 ± 0.11 g, t = 5.628, P < 0.001)compared with the control group. Conclusion: Abnormal expression of Wnt3a could be expected as a promising target for HCC gene therapy.

[Clinical values of Wnt3a as a novel biomarker in diagnosis and prognosis of hepatocellular carcinoma].

Objective: To explore Wnt3a expression in HCC tissues and serum, and to discuss its clinical diagnostic and prognostic value. Methods: The Wnt3a expressions were detected in a total of 186 patients (HCC, liver cirrhosis and chronic Hepatitis) and 40 controls by Elisa, comparing with AFP to evaluate its clinical diagnosis value. Wnt3a expressions in 80 HCC and surrounding tissues were analyzed by IHC, to explore its prognostic value. Results: Wnt3a with brown staining was mainly distributed in cytosol and of hepatocyte membrane. The higher expression (3-6 scores) was 71.3% in HCC, 13.8% in surrounding tissues, associated with poorly-differentiated grade, liver cirrhosis, HBV infection, higher TNM stage (P<0.05) and 5-year survival rate (P<0.001), identified as independent predictive factors for poor HCC outcome and closely related with lower five-year survival rate. Serum average Wnt3a levels were significantly higher (P<0.001) in the HCC group than those in any other groups of benign liver diseases, with about 4.0, 9.2 and 26.7 times higher than that in the liver cirrhosis, chronic hepatitis and normal control group. Wnt3a expression in HCC were closely related to AFP concentration, liver cirrhosis HBV infection, poor differentiation, TNM stagingand extra- hepatic metastasis (P<0.05). The sensitivity, specificity, accuracy, positive predictive value and negative predictive values were 92.5, 94.3, 93.2, 96.1 and 89.3% at 800 ng/L as cutoff value for Wnt3a. Combining Wnt3a and AFP test, the total sensitivity could rise to 96.3%. The area under ROC curve in Wnt3a (0.994)was higher than in AFP (0.710). Conclusions: Wnt3a as a critical signal molecule in the Wnt pathway is a new specific marker for HCC diagnosis and prognosis.

[Abnormal expression of insulin-like growth factor-I receptor and inhibitory effect of its transcription intervention on nude mice xenograft tumor].

Objective: To investigate the expression of insulin-like growth factor-I receptor (IGF-IR) in liver cancer and the inhibitory effect of its transcription intervention on nude mice xenograft tumor. Methods: A total of 40 patients with primary liver cancer were enrolled, and 40 samples of cancer lesions, peri-cancerous tissues (with a distance of 2 cm to the margin of cancer lesion), or distal liver tissues (with a distance of 5 cm to the margin of cancer lesion), with a weight of 200 mg, were collected after surgery. Some of these samples were used for pathological examination, and the rest were stored at -85°C. A total of 18 BALB/c nude mice aged 4-6 weeks with a body weight of 18-20 g (9 male and 9 female mice) were randomly divided into control group, negative control group, and co-intervention group, with 6 mice in each group, and fed under specific pathogen-free conditions. The cell line was cultured in the dimethyl sulfoxide complete medium containing 10% fetal bovine serum in a CO2incubator at 37°C. When the cell confluence reached 90% after cell inoculation, shRNA was divided into co-intervention group, negative control group, and untreated control group and were transfected to hepatoma cells using PolyJetTM transfection reagent. Stable cell clones obtained by G418 screening and used for the in vivo study. Immunohistochemistry, Western blotting, and quantitative real-time PCR were used to analyze the expression of IGF-IR in the human hepatoma tissue and cell line. The IGF-IR shRNA eukaryotic expression plasmids were established and screened for the most effective sequence; they were transfected to PLC/PRF/5 hepatoma cells, and the CCK-8 assay was used to analyze the changes in cell proliferation. The stable cell line screened out by G418 was inoculated to establish the subcutaneous xenograft tumor in nude mice. The tumor growth curve was plotted and histological examination was performed. Graphpad Prism 5.0 and SPSS 18.0 were used for plotting and data analysis; the variance test and Q test were used for comparison of means between multiple samples, the t-test was used for comparison of means between any two samples, the chi-square test or Fisher's exact test was used for comparison of rates between samples, and a rank correlation analysis was performed for expression intensity. Results: The liver cancer group had a significantly higher positive rate of IGF-IR than the peri-cancerous group and distal tissue group (82.5% vs 42.5%/10%,χ2= 13.653 and 42.29, bothP< 0.01), as well as significantly higher expression intensity than these two groups (Z= 4.771 and 6.579, bothP< 0.01). IGF-IR was not significantly expressed in the L02 cell line and was strongly expressed in the PLC/PRF/5 hepatoma cells, and the expression intensity of IGF-IR in the PLC/PRF/5 hepatoma cells was 4 and 5 times that in Bel-7404 cells and HepG2 cells, respectively. After the PLC/PRF/5 hepatoma cells were transfected with shRNA4 with the best co-intervention effect, the mean inhibition rate of tumor cell growth reached 63.9% at 72 hours, and the mean inhibition rate of IGF-IR transcription reached 59.6%. Tumor cells were arrested in G1 phase, and there was a significant increase in apoptosis rate. As for the subcutaneous hepatoma xenograft in nude mice, the intervention group had significantly slower tumor growth than the blank control group and negative control group (143±24 mm3 vs 372±46 mm3/350±50 mm3,t= 10.776 and 9.142, bothP< 0.01); the intervention group had significantly downregulated IGF-IR expression, which was significantly lower than that in the blank control group and negative control group (t= 11.184 and 9.450, bothP< 0.01). Conclusion: Intervention of IGF-IR transcription can effectively inhibit the growth of xenograft tumor in nude mice, suggesting that IGF-IR gene might become a new potential target for the treatment of liver cancer.

[Role of inhibition of nuclear factor-kappa B gene transcription by specific miRNA in reversing multi-drug resistance of liver cancer].

Objective: To investigate the reversal effect of inhibition of nuclear factor-kappa B (NF-κB) gene transcription by specific miRNA on multi-drug resistance (MDR)of liver cancer. Methods: The expression of P-glycoprotein (P-gp) and NF-κB in hepatoma cells, drug-resistant HepG2/ADM cells, and liver cells (LO2 cells) was analyzed. Specific NF-κB miRNA plasmids were constructed, screened, and transfected into HepG2 or HepG2/ADM cells. Western blot was used to measure the concentrations of P-gp and NF-κB, and FQ-PCR was used to measure gene expression; Cell Counting Kit-8 assay was used to measure cell proliferation and the influence of drugs on cell proliferation; flow cytometry and Annexin-V-PE/7-ADD double staining were used to observe cell cycle and apoptosis. The t-test was used to compare means between groups, and a one-way analysis of variance was used to compare means between multiple groups. Results: After being treated by adriamycin, hepatoma cells showed increased expression of P-gp and an increased level of NF-κB phosphorylation. At 24, 48, and 72 hours, the resistance index of the HepG2/ADM cells (IC50 = 4.166, 1.522, and 1.380 µmol/L) was 8.519, 6.874, and 6.166 times that of the HepG2 cells (IC50 = 0.489, 0.221, and 0.224 µmol/L). The HepG2/ADM cells showed significantly higher relative mRNA expression (∆ct value) of mdr1 and NF-κB than the HepG2 cells (3.310±0.154/2.580±0.040 vs 0.084±0.038/0.6067±0.032, both P < 0.01). After being transfected with miRNA1, the HepG2/ADM cells showed significantly lower mRNA expression of mdr1 than the cells in the miRNA-negative group (2-∆∆ct = 0.326±0.011 vs 0.804±0.057, t = 14.262, P < 0.01), as well as significant reductions in the expression of intracellular t-p65, nuclear p-p65, and P-gp compared with the cells in the miRNA-negative group (P < 0.01), with inhibited cell proliferation, G1 phase arrest, and increased apoptosis. Conclusion: Abnormal expression of MDR1/P-gp is closely associated with MDR, and inhibition of NF-κB activation by specific miRNA can significantly inhibit MDR1/P-gp gene transcription and reverse MDR of liver cancer.

Comparative analysis of platelet 5-HT concentrations in Han and Li patients with post-traumatic stress disorder.

We investigated the role of serotonin (5-HT) in the pathogenesis of post-traumatic stress disorder (PTSD) by determining the platelet 5-HT concentrations in Li and Han patients with PTSD in Hainan Province, China. Li and Han control groups of the same sample size have no statistical differences in gender and age distribution compared to those in the PTSD groups who were also examined. The platelet 5-HT concentrations were determined by high-performance liquid chromatography. In addition, the patients and controls were evaluated by the impact of event scale-revised (IES-R). IES-R showed that the total and sub-scale scores of three factors (avoidance, intrusion, and hyperarousal) of Li patients with PTSD were significantly higher than those of Han patients with PTSD. Scores of both PTSD groups were higher than those of their respective control groups. The platelet 5-HT concentration of the Li patients with PTSD (120.56 ± 118.05 ng/10(9) platelets) was lower than that of the Han patients with PTSD (271.43 ± 181.66 ng/10(9) platelets) and that of both Li and Han control groups (338.54 ± 156.46, 350.58 ± 169.19 ng/10(9) platelets, respectively). Differences existed in symptoms of PTSD in terms of avoidance, intrusion, and hyperarousal in the Li and Han patients with PTSD. The diminished 5-HT activity in patients with PTSD may be relevant to biochemical changes in the brain and body. The differences in these factors between ethnic groups could be due to their customs, social status, and culture.

Losartan reduces insulin resistance by inhibiting oxidative stress and enhancing insulin signaling transduction.

BACKGROUND: Inhibition of the rennin-angiotensin system (RAS) could reduce insulin resistance in patients with hypertension and diabetic kidney disease (DKD), but whether the effect of losartan on insulin resistance is associated with reduction of oxidative stress and enhancement of insulin signaling transduction has not been fully elucidated. METHODS: 130 patients with type 2 DKD were randomly assigned into 2 groups, the losartan group (n=65, 100 mg orally daily for 12 months) and the amlodipine group (n=65, 10 mg orally daily for 12 months). Oxidative stress markers in plasma, urine concentrations of 8-hydroxy-2'-deoxyguanosine (8-OHdG) and nitrotyrosine (NT) as well as SOD activity were measured by ELISA. After in vitro treatment with different doses of losartan (10, 100 µmol/L) or amlodipine for 48 h, the size of H2O2-induced adipocytes and glucose consumption were measured. Western blot was performed to investigate IRS-1 serine phosphorylation level as well as the protein expressions of phosphorylated insulin receptor (pIR), phosphatidylinositol 3- kinase (PI3K) and insulin receptor substrate 1 (IRS-1) in 3T3-L1 adipocytes. RESULTS: After 12-month treatment, there were no significant differences in systolic and diastolic blood pressures decreases, plasma fasting blood glucose and HbA1c between the 2 groups. Compared with amlodipine group, fasting blood insulin levels and insulin resistance index (HOMA-IR) were significantly decreased in losartan group, and in addition, the circulating levels of 8-OHdG and NT were significantly decreased in losartan group, while the serum SOD activity was enhanced. There were significant positively correlations of HOMA-IR with inflammatory oxidative stress markers. In vitro study showed that losartan could increase glucose uptake in 3T3-L1 adipocytes (P<0.01) and decrease adipocyte size (P<0.01), while amlodipine can't. Losartan can also enhance adiponectin (P<0.05) and decrease TNF-α (P<0.05) and IL-6 (P<0.01) secretion, while amlodipine can't. The protein expressions of pIR, IRS-1 and PI3K were significantly increased after treatment with losartan (P<0.01), while the level of IRS-1 serine phosphorylation was decreased (P<0.01), which could be blocked by specific PI3K inhibitor wortmannin. CONCLUSIONS: These results suggest that the effect of losartan on insulin resistance is associated with the reduction of oxidative stress and inflammation in patients with type 2 DKD as well as the activation of insulin signal pathway in insulin-resistance 3T3-L1 adipocytes through modulation of PI3K pathway. (Clinical Trials. gov number, NCT 00774904).

Efficacy and safety of gabapentin for treatment of postherpetic neuralgia: a meta-analysis of randomized controlled trials.

BACKGROUND: Postherpetic neuralgia (PHN) is a common type of neuropathic pain occurring after resolution of herpes zoster rash. Although gabapentin is a widely used treatment, some disagreements exist about its efficacy and safety. Meta-analysis was performed to better evaluate the efficacy and safety of gabapentin for management of PHN. METHODS: Randomized, double-blind, placebo-controlled trials of gabapentin to treat PHN were identified by searching MEDLINE, EMBASE, and CENTRAL databases. Searches were restricted to studies published in English. RESULTS: Seven trials involving a total of 2039 participants were identified. Pooled analysis showed that gabapentin reduced PHN-related pain significantly more than placebo (mean difference, MD=-0.89, 95% CI -1.58 to -0.18, P<0.001). Gabapentin reduced pain below baseline by at least 50% in significantly more patients than did placebo (RR=1.59, 95% CI 1.35 to 1.88, P<0.001). Gabapentin was significantly more likely than placebo to lead patients to rate their global impression of change as "much improved" or "very much improved" (RR=1.82, 95% CI 1.41 to 2.35, P=0.003). Gabapentin also improved sleep quality significantly more than did placebo (MD=-0.62, 95% CI -0.67 to -0.57, P<0.001). On the other hand, patients given gabapentin were significantly more likely to experience dizziness, somnolence, peripheral edema, ataxia or gait disturbance and diarrhea. Subgroup analysis on formulation of gabapentin showed that gabapentin enacarbil had similar efficacy of pain relief with other formulations while it may be superior to others in term of compliance and safety. CONCLUSION: This meta-analysis indicates that gabapentin is an effective and well-tolerated treatment for patients with PHN.

Type II alveolar epithelial cells and interstitial fibroblasts express connective tissue growth factor in IPF.

Connective tissue growth factor (CTGF) is a growth and chemotactic factor for fibroblasts encoded by an immediate early gene that is transcriptionally activated by transforming growth factor-beta. Previous studies have shown that both CTGF messenger ribonuclear acid (mRNA) and protein are expressed in renal fibrosis and bleomycin-induced pulmonary fibrosis in mice. The aim of the present study was to investigate the localization of CTGF protein and its mRNA expression in the fibrotic lung tissue of patients with idiopathic pulmonary fibrosis (IPF). Using human fibrotic lung tissue obtained from eight autopsy cases and four biopsy cases with IPF, immunohistochemical staining, in situ hybridization, and reverse transcription-polymerase chain reaction (RT-PCR) were performed. The cellular immunoreactivity for CTGF was markedly increased in the lung tissue of patients with IPF, compared to normal lungs. The immunolocalization of CTGF was confined predominantly to proliferating type II alveolar epithelial cells and activated fibroblasts. In the normal lung, type II alveolar epithelial cells stained for CTGF were sparsely distributed. CTGF mRNA was localized in proliferating type II alveolar epithelial cells and activated fibroblasts in the interstitium of fibrotic lung tissues. RT-PCR analysis showed that CTGF mRNA was expressed at a higher level in fibrotic lungs than in normal lungs. In both an autocrine and a paracrine manner, type II alveolar epithelial cells and activated fibroblasts may play a critical role in pulmonary fibrosis by producing connective tissue growth factor which modulates fibroblast proliferation and extracellular matrix production.

Effects of pranlukast, a leukotriene receptor antagonist, on airway inflammation in mild asthmatics.

To determine the anti-inflammatory actions of pranlukast, a cysteinyl leuklotriene receptor antagonist, we measured exhaled nitric oxide (NO) concentrations and eosinophil ratio in induced sputum of three groups of mild asthmatics (n = 30): treated with bronchodilators alone, with bronchodilators and inhaled steroid (beclomethasone dipropionate; 400 microg/day), and bronchodilators and pranlukast (450 mg/day). Pranlukast (450 mg/day) reduced the eosinophil ratio in the induced sputum significantly (p < 0.01) without a major effect on the concentration of exhaled NO. Pranlukast also increased values of peak expiratory flow significantly (p < 0.05). Pranlukast may be useful for mild asthmatics, in part through its ability to suppress eosinophilic airway infiltration.

Inhibition of binding of E- and P-selectin to sialyl-Lewis X molecule suppresses the inflammatory response in hypersensitivity pneumonitis in mice.

The carbohydrate structure of sialyl-Lewis X (SLe(x)) can function as a ligand for E- and P-selectin, which play important roles in mediating the initial interactions of leukocytes with the endothelium in inflammatory responses. In this study we evaluated the effects of inhibiting E- and P-selectin function with the SLe(x) molecule on the inflammatory response in an experimental murine model of hypersensitivity pneumonitis (HP). Antigen exposure induced marked interstitial and especially perivascular and peribronchiolar infiltration with lymphocytes and granuloma formation, in murine lung sensitized with Saccaropolyspora rectivirgula. These pathologic changes were significantly suppressed with SLe(x) ganglioside analogues through a reduction in the numbers of lymphocytes in bronchoalveolar lavage fluid, as evidenced by the lung index and histologic scores indicating the severity of the inflammatory response. Using specific antibodies, we also evaluated the immunohistochemical localization of SLe(x) in mononuclear cells in granulomas, and of E- and P-selectin in vascular endothelium. Our findings suggest that the molecular interaction between SLe(x), and E- and P-selectin mediates lymphocyte recruitment into the lung parenchyma, which is critical for the inflammatory response in experimental murine models of HP.

Localization of nerve growth factor, trkA and P75 immunoreactivity in the hippocampal formation and basal forebrain of adult rats.

In the immunohistochemical staining of nerve growth factor, it has been reported that fixation-dependent lability of nerve growth factor hampers its localization. In the present study, we used two different polyclonal antibodies to immunostain nerve growth factor in rat brain tissue. We found that in paraformaldehyde-fixed (immersion- or perfusion-fixed) brains, nerve growth factor-like immunoreactivity was located primarily in the cytoplasmic membrane and fiber tract of hippocampal neurons and was sparse in cortical neurons. When fresh frozen brain sections were fixed in paraformaldehyde solution, nerve-growth factor-like immunoreactivity was distributed evenly in the cell body. However, when fresh frozen brain sections were fixed in acetone, immunoreactivity to nerve growth factor was present as discrete or confluent dense particles in the cell body, especially in the nuclear region. Also, when paraformaldehyde-perfusion-fixed brain sections were heat treated in salt solution before immunostaining, nerve growth factor-like immunoreactivity could be retrieved in the cytoplasmic and nuclear regions. The hippocampal formation, cerebral cortex and basal forebrain expressed nerve growth factor-like immunoreactivity. Double immunostaining in fresh frozen brains showed that the low-affinity nerve growth factor receptor (p75) co-expressed with nerve growth factor and trkA proto-oncogene in basal forebrain neurons. Our study shows that formaldehyde fixation can mask nerve growth factor antigen, and special treatment, such as heating, is needed to retrieve nerve growth factor antigen to permit immunohistochemical detection. For immunohistochemical study of nerve growth factor in rat brain tissue, successful immunostaining can be obtained by using fresh frozen brains to prevent the masking effect of fixatives or by using paraformaldehyde-fixed brains with heat treatment. It is likely that nerve growth factor is synthesized and accumulated mainly in the cell body but not in the fiber tracts, which is similar to the distribution of its messenger RNA. The co-existence of p75 with nerve growth factor and trkA in basal forebrain neurons suggests the role of low- and high-affinity receptors in regulating the trophic effect of nerve growth factor.

Upregulation of protein-tyrosine nitration in the anterior horn cells of amyotrophic lateral sclerosis.

Spinal cords of sporadic cases with amyotrophic lateral sclerosis (ALS) and normal controls were immunohistochemically examined using antibodies for nitrotyrosine (NT), Cu/Zn superoxide dismutase (SOD), and nitric oxide synthase (NOS) of brain, endothelial, and inducible forms. Immunoreactivity for NT was densely detected in the motor neurons of ALS while it was not or was only minimally detected in those of controls. The staining was also found in the axons of motor neurons of ALS, but was not found in the controls. In contrast, although immunoreactivity for Cu/Zn SOD of the motor neurons was dense in the motor neurons, it was not different between the ALS and controls. Immunoreactivities for bNOS and eNOS in the motor neurons of ALS were stronger than those of controls, and were also found in degenerated axons in the anterior horn of ALS. However, the immunoreactivity for inducible NOS was only minimally detected in the motor neurons of ALS and controls, and was not detected in the degenerated axons of ALS. These results suggest that nitration of protein-tyrosine residue is upregulated in motor neurons of the spinal cord of ALS with selective increases of brain NOS- and endothelial NOS-like immunoreactivities.

Co-expression of TNF alpha and IL-1 beta in human acute pulmonary fibrotic diseases: an immunohistochemical analysis.

To clarify the involvement of TNF alpha and IL-1 beta in the initiation of fibrotic lung diseases, their localization was examined by immunohistochemistry. Fibrotic lung diseases observed were classified into acute and old pulmonary fibrotic changes. The acute fibrotic changes included adult respiratory distress syndrome, acute interstitial pneumonia and idiopathic pulmonary fibrosis with acute exacerbation. Acute pulmonary fibrotic changes histopathologically corresponded to a mixture of the exudative and proliferative phases of diffuse alveolar damage. Both TNF alpha and IL-1 beta were positive in the alveolar macrophages and proliferating type II pneumocytes in acute fibrotic changes. In contrast, positive cells for TNF alpha and IL-1 beta were sparse in the areas of old fibrotic change and in the normal tissue. These findings suggest that TNF alpha and IL-1 beta play an important role in the initiation of pulmonary fibrotic responses and in the architectural remodeling, irrespective of the etiology of fibrotic lung diseases.

Induction of nitrotyrosine-like immunoreactivity in the lower motor neuron of amyotrophic lateral sclerosis.

Spinal cords of sporadic cases with amyotrophic lateral sclerosis (ALS) and normal controls were immunohistochemically examined using antibodies for Cu/Zn superoxide dismutase (SOD) and nitrotyrosine (NT). Immunoreactivity for Cu/Zn SOD of the motor neurons was not different between the ALS and controls. In contrast, immunoreactivity for NT was densely detected in motor neurons of ALS but was not or was only minimally detected in those of controls. The staining was also found in the axons of motor neurons of ALS, but was not found in the controls. These results suggest that nitration of protein-tyrosine residue is upregulated in motor neurons of the spinal cord of ALS.

Identification of different mechanisms of action for increases of food intake and plasma ACTH concentration following 5-HT1a receptor subtype activation in rat brain.

Both food intake and pituitary ACTH release respond to activation of serotonergic 5-HT1a receptors. However, the effects of the 5-HT1a agonist 8-OH-DPAT on these two paradigms are probably mediated by different mechanisms. Ten micrograms of 8-OH-DPAT were microinjected into the rat paraventricular nuclei (PVN) of the hypothalamus and elicited an elevation of plasma ACTH concentration, but did not change food consumption when compared with controls. On the other hand, microinjection of the same dose of 8-OH-DPAT into the rat dorsal raphé nucleus increased food intake, but failed to alter plasma ACTH levels. This suggests that, among its various possible mechanisms of action, 8-OH-DPAT induces an increase of food intake in rats by activating presynaptic 5-HT1a autoreceptors in the raphé nuclei, where most serotonergic fibers originate, while its effect on plasma ACTH concentration occurs through activation of postsynaptic 5-HT1a receptors in the PVN, where some serotonergic fibers terminate.