Strategic Aspects of NPY-Based Monoclonal Antibodies for Diagnosis and Treatment of Breast Cancer.

Immunotherapy emerges as a treatment strategy for breast cancer marker, diagnosis and treatment. In this review, monoclonal antibodies (mAbs)-based passive and peptide vaccines as active immunotherapy approaches like activation of B-cells and T-cells are studied. Passive immunotherapy is mAbs-based therapy effective against tumor cells, which acts by targeting HER2, IGF 1R, VEGF, BCSC and immune checkpoints. Neuropeptide Y (NPY) and GPCR are the areas of interest to target BC metastases for on-targeting therapeutic action. Neuropeptide S (NPS) or NPS receptor 1, acts as a biomarker for Neuroendocrine tumors (NET), mostly characterized by synaptophysin and chromogranin-A expression or Ki-67 proliferation index. The protein fusion technologies arise as a promising avenue in plant expression systems for increased recombinant Ab accumulation and cost-efficient purification. Recently, mAbs-based immunotherapy effectiveness is appreciated as a novel therapeutic combination of chemotherapy and immunotherapy to reduce the side effects and improve therapeutic responsiveness. Synthetic drug resistance will be overcome by mAbs-based therapy through several clinical trials and detection methods need to be optimized for accuracy and precision. Pharmacokinetic attributes need to be accessed for preferred receptor-agonist activity without ligand accumulation.

Neuroimmunomodulation in the mucosa of the alimentary tract / Neuroimmun-moduláció az emésztocsatorna nyálkahártyájában.

Neuropeptides synthetised in the enteric nervous system can change the function of the immunocells and play a role in inflammatory processes. In our review the effects of inflammation on the neuropeptide content of nerves and immune cells were compared. Inflamed tissue samples (human gastritis and animal models with experimental colitis and streptozotocin-induced diabetes mellitus) were examined. The number and contacts of neuropeptide-containing nerves and immune cells were studied using immunohistochemistry, confocal laser microscopy and electronmicroscopy. In inflammation, the number of substance P, vasoactive intestinal polypeptide and neuropeptide Y nerve fibres was increased significantly in parallel with the strongly increased number of immunocompetent cells (p<0.001). In inflammatory diseases, a large number of lymphocytes and mast cells were also positive for these neuropeptides. Very close morphological relationship between substance P and neuropeptide Y immunoreactive nerve fibres and immunocells could be demonstrated only in inflamed mucosa. Some of the substance P immunoreactive immunocells were also immunoreactive for tumor necrosis factor alpha and nuclear factor kappa B in the case of inflammation. The increased number of tumor necrosis factor alpha and nuclear factor kappa B immunoreactive immune cells correlated with the increased number of substance P-containing nerve fibres. Substance P, vasoactive intestinal polypeptide and neuropeptide Y released from nerve fibres and immunocells can play a role in inflammation. Our results suggest that using substance P antagonists or vasoactive intestinal polypeptide and neuropeptide Y peptides might be a novel therapeutic concept in the management of inflammation. Orv Hetil. 2020; 161(35): 1436-1440.

Development of monoclonal mouse antibodies that specifically recognize pancreatic polypeptide.

Pancreatic polypeptide (PP) is a 36-amino acid peptide encoded by the Ppy gene, which is produced by a small population of cells located in the periphery of the islets of Langerhans. Owing to the high amino acid sequence similarity among neuropeptide Y family members, antibodies against PP that are currently available are not convincingly specific to PP. Here we report the development of mouse monoclonal antibodies that specifically bind to PP. We generated Ppy knockout (Ppy-KO) mice in which the Ppy-coding region was replaced by Cre recombinase. The Ppy-KO mice were immunized with mouse PP peptide, and stable hybridoma cell lines producing anti-PP antibodies were isolated. Firstly, positive clones were selected in an enzyme-linked immunosorbent assay for reactivity with PP coupled to bovine serum albumin. During the screening, hybridoma clones producing antibodies that cross-react to the peptide YY (PYY) were excluded. In the second screening, hybridoma clones in which their culture media produce no signal in Ppy-KO islets but detect specific cells in the peripheral region of wild-type islets, were selected. Further studies demonstrated that the selected monoclonal antibody (23-2D3) specifically recognizes PP-producing cells, not only in mouse, but also in human and rat islets. The monoclonal antibodies with high binding specificity for PP developed in this study will be fundamental for future studies towards elucidating the expression profiles and the physiological roles of PP.

Gastrointestinal neuroendocrine peptides/amines in inflammatory bowel disease.

Inflammatory bowel disease (IBD) is a chronic recurrent condition whose etiology is unknown, and it includes ulcerative colitis, Crohn's disease, and microscopic colitis. These three diseases differ in clinical manifestations, courses, and prognoses. IBD reduces the patients' quality of life and is an economic burden to both the patients and society. Interactions between the gastrointestinal (GI) neuroendocrine peptides/amines (NEPA) and the immune system are believed to play an important role in the pathophysiology of IBD. Moreover, the interaction between GI NEPA and intestinal microbiota appears to play also a pivotal role in the pathophysiology of IBD. This review summarizes the available data on GI NEPA in IBD, and speculates on their possible role in the pathophysiology and the potential use of this information when developing treatments. GI NEPA serotonin, the neuropeptide Y family, and substance P are proinflammatory, while the chromogranin/secretogranin family, vasoactive intestinal peptide, somatostatin, and ghrelin are anti-inflammatory. Several innate and adaptive immune cells express these NEPA and/or have receptors to them. The GI NEPA are affected in patients with IBD and in animal models of human IBD. The GI NEPA are potentially useful for the diagnosis and follow-up of the activity of IBD, and are candidate targets for treatments of this disease.

Cross-talk between innate cytokines and the pancreatic polypeptide family in acute pancreatitis.

BACKGROUND AND AIM: Low-grade inflammation persists in patients with acute pancreatitis (AP) after hospital discharge, and is linked to metabolic disorders. Neuropeptide Y (NPY) is well recognized as an important mediator of inflammation in these patients but the role of the other two structurally similar peptides, pancreatic polypeptide (PP) and peptide YY (PYY), in inflammation has been sparsely investigated. The aim was to investigate the association between PYY, PP, NPY and circulating levels of innate cytokines in patients after AP. METHODS: Fasting blood samples were collected to measure PYY (ng/mL), PP (ng/mL), NPY (pg/mL), interleukin-6 (IL-6) (ng/mL), monocyte chemoattractant protein (MCP) 1 (ng/mL), and tumour necrosis factor (TNF) α (ng/mL). Modified Poisson regression analysis and linear regression analyses were conducted. Age, sex, ethnicity, obesity, diabetes, aetiology, time from 1st attack of AP, recurrence, severity, physical activity, and smoking were adjusted for in several statistical models. P<0.05 was considered statistically significant. RESULTS: A total of 93 patients were recruited. Peptide YY was significantly associated (p<0.001) with IL-6, MCP-1, and TNFα in the unadjusted and all adjusted models. Pancreatic polypeptide was significantly associated (p<0.001) with IL-6, MCP-1, and TNFα in the unadjusted and at least one adjusted model. Peptide YY and PP together contributed 22.2%, 72.7%, and 34.6% to the variance of IL-6, MCP-1, and TNFα, respectively. Neuropeptide Y was not significantly associated with any of the three cytokines. CONCLUSIONS: Peptide YY and PP are associated with circulating innate pro-inflammatory cytokines in patients after AP and cumulatively contribute to nearly half of the variance of IL-6, MCP-1, and TNFα. Future research is warranted to investigate the signaling pathways that underlie these associations.

Chemical Coding of Sensory Neurons Supplying the Hip Joint Capsule in the Sheep.

Immunohistochemical properties of nerve fibres supplying the joint capsule were previously described in many mammalian species, but the localization of sensory neurons supplying this structure was studied only in laboratory animals, the rat and rabbit. However, there is no comprehensive data on the chemical coding of sensory neurons projecting to the hip joint capsule (HJC). The aim of this study was to establish immunohistochemical properties of sensory neurons supplying HJC in the sheep. The study was carried out on 10 sheep, weighing about 30-40 kg. The animals were injected with a retrograde neural tracer Fast Blue (FB) into HJC. Sections of the spinal ganglia (SpG) with FB-positive (FB+) neurons were stained using antibodies against calcitonin gene-related peptide (CGRP) substance P (SP), pituitary adenylate cyclase-activating peptide (PACAP), nitric oxide synthase (n-NOS), neuropeptide Y (NPY), vasoactive intestinal polypeptide (VIP), Leu-5-enkephalin (Leu-Enk), galanin (GAL) and vesicular acetylcholine transporter (VACHT). The vast majority of FB+ neurons supplying HJC was found in the ganglia from the 5th lumbar to the 2nd sacral. Immunohistochemistry revealed that most of these neurons were immunoreactive to CGRP or SP (80.7 ± 8.0% or 56.4 ± 4.8%, respectively) and many of them stained for PACAP or GAL (52.9 ± 2.9% or 50.6 ± 19.7%, respectively). Other populations of FB+ neurons were those immunoreactive to n-NOS (37.8 ± 9.7%), NPY (34.6 ± 6.7%), VIP (28.7 ± 4.8%), Leu-Enk (27.1 ± 14.6) and VACHT (16.7 ± 9.6).

[Changes in neuropeptide Y and substance P immunoreactive nerve fibres and immunocompetent cells in hepatitis]. / Neuropeptid Y és P anyag immunreaktív idegrostok és immunkompetens sejtek változása hepatitisben.

Neuropeptide Y and substance P were thought to play a role in the function of immune cells and in amplification or elimination of the inflammatory processes. In hepatitis the number of both neuropeptide Y and substance P immunoreactive nerve fibres are increased, where the increase of neoropeptide Y is significant. A large number of lymphocytes and mast cells are also stained for neuropeptide Y and substance P. Very close associations (less than 1 µm) were observed between neuropeptide Y immunoreactive nerve fibres and immune cells stained also with neuropeptide Y. Some immune cells were also found to be immunoreactive for tumor necrosis factor-α and NF-κB. Some of the SP IR immunocells were also stained for TNF-α and nuclear factor kappaB. Based on these data it is hypothesized that neuropeptid Y and substance P released from nerve fibres and immune cells play a role in inflammation and elimination of inflammation in hepatitis.

Neuroimmunomodulation in human autoimmune liver disease.

Bidirectional interaction between immune and nervous systems is considered an important biological process in health and disease. However, little is known about the mechanisms involved in their interaction in the human liver. This study examines the distribution of intrahepatic NPY, SP immunoreactive (IR) nerve fibers and their antomical relationship with immunocells containing tumor necrosis factor-α (TNF-α) and nuclear factor κB (NF-κB) in patients with autoimmune hepatitis. Liver specimens were obtained from control liver and autoimmune hepatitis patients. The immunoreactivity was determined by immunohisto- and immunocytochemistry and confocal laser microscopy. In hepatitis, the number of NPY-IR and SP-IR nerve fibers increased significantly. These IR nerve fibers were in very close contact with the lymphocytes. In healthy controls, no NPY-IR, SP-IR or NF-κB IR lymphocytes and only a few TNF-α positive cells, were observed. In hepatitis, some of the lymphocytes showed immunoreactivity for SP and NPY in the portal area. Fluorescent double-labeled immunostaining revealed that in these cells NPY did not colocalize with TNF-α or NF-κB. However, some of the SP fluorescence-positive immune cells exhibited immunostaining for p65 of NF-κB, where their labeling was detected in the nuclei. Under the electronmicroscope, these cells could be identified (lymphocytes, plasmacells and mast cells). The gap between the IR nerve fibers and immunocells was 1 µm or even less. Overexpression of SP in lymphocytes may amplify local inflammation, while NPY may contribute to liver homeostasis in hepatitis. Neural immunomodulation (SP antagonists and NPY) might be a novel therapeutic concept in the management of liver inflammation.

The neuropeptides α-MSH and NPY modulate phagocytosis and phagolysosome activation in RAW 264.7 cells.

Within the immunosuppressive ocular microenvironment, there are constitutively present the immunomodulating neuropeptides alpha-melanocyte stimulating hormone (α-MSH) and neuropeptide Y (NPY) that promote suppressor functionality in macrophages. In this study, we examined the possibility that α-MSH and NPY modulate phagocytic activity in macrophages. The macrophages treated with α-MSH and NPY were significantly suppressed in their capacity to phagocytize unopsonized Escherichia coli and Staphylococcus aureus bioparticles, but not antibody-opsonized bioparticles. The neuropeptides significantly suppressed phagolysosome activation, and the FcR-associated generation of reactive oxidative species as well. This suppression corresponds to neuropeptide modulation of macrophage functionality within the ocular microenvironment to suppress the activation of immunogenic inflammation.

Neuropeptide Y induces secretion of high-mobility group box 1 protein in mouse macrophage via PKC/ERK dependent pathway.

Despite increasing evidence highlighting the role of NPY in the modulation of inflammatory reaction, surprisingly little is known about the direct effects of NPY on the release of proinflammatory mediators. In the present work, we have evaluated the effects of NPY on the release of TNF-α, IL-1ß, IL-6 and HMGB1 mediators in peritoneal macrophages. Our results demonstrate for the first time that NPY can directly induce active HMGB1 release and cytoplasmic translocation, while the production of TNF-α, IL-1ß and IL-6 is not affected. PKC and ERK pathway inhibitors can abolish the promotive effect of NPY on HMGB1 secretion. Thus, our results indicate that NPY might impact on the innate immune system by directly potentiating the HMGB1 release from the macrophage.

Potential role of neurogenic inflammatory factors in the pathogenesis of vitiligo.

BACKGROUND: Vitiligo is a highly complex multifactorial condition of the skin that has an unclear mechanism of pathogenesis. OBJECTIVE: This review summarizes the role of various neurogenic inflammatory factors significantly upregulated in vitiligo. METHODS: A literature review was conducted of all pertinent data regarding neuropeptides that are altered in vitiligo and their possible role in the destruction of melanocytes. RESULTS: The close associations between the skin, immune system, and nervous system, along with specific changes demonstrated in vitiligo patients, support a pathogenic mechanism of vitiligo that involves neuroimmunologic factors, the release of which can be governed by mental stress. CONCLUSION: Neuropeptides and nerve growth factors are critical regulators of emotional response and may precipitate the onset and development of vitiligo in certain predisposed individuals. More studies are required to investigate whether a direct link exists between genetics, mental stress, and neurogenic factors in vitiligo.

Localized retinal neuropeptide regulation of macrophage and microglial cell functionality.

The functionality of immune cells is manipulated within the ocular microenvironment to protect the sensitive and non-regenerating light-gathering tissue from the collateral damage of inflammation. This is mediated partly by the constitutive presence of immunomodulating neuropeptides. Treating primary resting macrophages with soluble factors produced by the posterior eye induced co-expression of Arginase1 and NOS2. The neuropeptides alpha-melanocyte stimulating hormone and Neuropeptide Y alternatively activated the macrophages to co-express Arginase1 and NOS2 like myeloid suppressor cells. Similar co-expressing cells were found within healthy, but not in wounded retinas. Therefore, the healthy retina regulates macrophage functionality to the benefit of ocular immune privilege.

[Neuroimmuno-modulation in gastric mucosa]. / Neuroimmunmoduláció a gyomornyálkahártyában.

UNLABELLED: Several neuropeptides were supposed to take place in the protection of gastric mucosa and play role in the development of gastritis. AIM OF THE STUDY: To investigate morphological relationship between nerve fibres and immunocytes, to find out if these cells synthetize some neuropeptides and if there is there any co-existence with TNF-α and NFκ-B. METHODS: Immunohistochemical, confocal laser microscopic methods were used to investigate nerve fibres, immunocompetent cells in control and gastritis mucosa. RESULTS: The number of neuropeptide-containing nerve fibres increased significantly. In control stomach the number of lymphocytes, plasma cells, and mast cells was low and showed no immunoreactivity for neuropeptide antibodies. However, in gastritis, some of the immunocompetent cells were immunoreactive for SP and for NPY. Some of the SP immunoreactive cells showed also positive reaction for TNF-α and NFκ-B. The distance between nerve fibres and immunocytes was 1 µm or less. CONCLUSIONS: The increase of neuropeptides released from nerve fibres and immunocompetent cells can take part in neurogenic inflammation and generate chronic gastritis.

Modulation of granulocyte functions by peptide YY in the rat: age-related differences in Y receptors expression and plasma dipeptidyl peptidase 4 activity.

It has been acknowledged that aging exerts detrimental effects on cells of the innate immune system and that neuropeptides, including neuropeptide Y (NPY) and NPY-related peptides fine-tune the activity of these cells through a receptor specific mechanism. The present study investigated the age-dependent potential of peptide YY (PYY) to modulate different granulocyte functions. The PYY reduced the carrageenan-elicited granulocyte accumulation into the air-pouch of aged (24 months) rats, and markedly decreased the phagocytosis of zymosan, as well as the H(2)O(2) production, when applied in vivo (20 microg/air-pouch). The anti-inflammatory effect of PYY was less prominent in adult (8 months) and young (3 months) rats. However, the proportions of granulocytes expressing Y1, Y2 and Y5 receptor subtypes were significantly lower in both aged and young rats when compared to adult rats. Furthermore, the aging was found to be associated with the diminished dipeptidyl peptidase 4 (DP4, an enzyme converting the NPY and PYY to Y2/Y5 receptor selective agonists) activity in plasma. In conclusion, the diverse age-related anti-inflammatory effect of PYY in rats originates from different expression levels of Y1, Y2, and Y5 receptor subtypes in addition to different plasma DP4 activity.

Marked sympathetic component in the perivascular innervation of the dorsal paratendinous tissue of the patellar tendon in arthroscopically treated tendinosis patients.

During the recent years, a few studies have shed new light on the innervation patterns of the human patellar tendon, but the area of the loose paratendinous connective tissue dorsal to the proximal tendon proper has yet not been investigated. That is a drawback, since this is the area targeted in promising treatment regimens of chronic painful patellar tendinosis, namely sclerosing Polidocanol injection therapy, and a new surgical method conforming to ultrasound and color Doppler guided arthroscopic shaving, directed at neovessels found in the region. The present study thus aimed at investigating the paratendinous area dorsal to the proximal patellar tendon proper in seven patients being operated for tendinosis. Biopsies were collected through the new arthroscopic technique, approaching the tendon from the dorsal side. Samples were investigated using immunohistochemistry with antibodies delineating general (PGP 9.5), sensory (SP/CGRP), and sympathetic (TH/NPY) nerve patterns, and also antibodies against alpha1- and alpha2A-adrenoreceptors. Both small and large blood vessels had a marked perivascular innervation (PGP 9.5). Surprisingly, this perivascular innervation was found only to a very limited extent to correspond to sensory nerves, while there were marked immunoreactions for sympathetic markers. Adrenoreceptor immunoreactions frequently occurred in blood vessel walls. In conclusion, this study demonstrates, for the first time, the innervation patterns of the area dorsal to the patellar tendon in man. It shows that the area investigated is under marked influence by the sympathetic nervous system. Thus, sympathetic effects are likely to occur for blood vessels of the area, which is interesting since color Doppler has revealed that vessels of this area ("neovessels") display a pathologically high blood flow in tendinosis. The findings are discussed in relation to aspects of vascular regulation, and to pain symptoms of tendinosis.

Short-term cold exposure may cause a local decrease of neuropeptide Y in the rat hypothalamus.

Neuropeptide Y (NPY) is an orexigenic and hypothermic peptide. To understand its role in hypothermic conditions, male rats were placed in a 24 degrees C or 4 degrees C air chamber for 1.5 h. The expression of c-Fos protein, and NPY mRNA and protein, was analyzed in the hypothalamus 1 h-2 h later. The cold treatment increased the number of c-Fos-immunoreactive cells in the paraventricular hypothalamic nucleus (PVN) and arcuate nucleus (ARC). At the same time it decreased the density of NPY-immunoreactive components in the PVN, dorsomedial hypothalamic nucleus and ARC, as well as of NPY transcripts in the PVN and ARC. No colocalization of c-Fos with NPY was detected. These results suggest that short-term cold exposure should reduce indirectly NPY production in some hypothalamic nuclei to facilitate thermogenesis without inducing feeding behavior.

[Changes of the different neuropeptide containing nerve elements in the inflamed human gall bladder]. / A küllözo neuropeptidtartalmú idegelemek számának változása humán gyulladt epehólyagban.

BACKGROUND, AIMS: The changes of different neuropeptide containing nerve elements might play a role in the pathogenesis of cholecystitis and the formation of gallstones, therefore the authors have investigated the density of the neuropeptide containing nerve fibres and immunocompetent cells in human gallbladder (control and cholecystitis). METHODS: The different neuropeptide containing nerve elements and immunocytes were detected by avidin-biotin-peroxidase (ABC) immunohistochemistry. RESULTS: In the control gallbladder the density of the different neuropeptide containing nerve fibres showed different pattern in all layers. In the inflamed gallbladder the number of the vasoactive intestinal polypeptide (VIP) positive nerve fibres increased significantly, very dense immunoreactive (IR) nerve fibres were located mainly in the tunica mucosa just below the epithelial lining. The number of the VIP IR nerve cell bodies was also increased. However, the number of the substance P (SP) IR nerve fibres was decreased significantly in the cholecystitis. The number of the neuropeptide Y (NPY) nerve fibres showed no changes, while their distribution was altered compared to the control. In the inflamed area the number of immunocompetent cells was strongly increased (being granulocytes, lymphocytes, plasma cells and mast cells) and some of them were also immunoreactive for SP, calcitonin gene-related peptide (CGRP) and VIP. Close contacts were detected between IR nerve fibres and the immunocytes in several cases. CONCLUSIONS: During inflammation the changes of the neuropeptide containing nerve fibres might alter the function (causing dilation) of the gall bladder, the activated immunocytes can also synthesize neuropeptides (SP, CGRP, VIP), so the released materials (cytokines, chemokines, histamine, as well as neuropeptides) might act in an autocrine and/or paracrine way influencing the function of the organ and of the immune system.

The chromogranin A fragment catestatin: specificity, potency and mechanism to inhibit exocytotic secretion of multiple catecholamine storage vesicle co-transmitters.

BACKGROUND: Secretory granules of chromaffin cells and neurons co-store and release, by exocytosis, the acidic soluble protein chromogranin A (human, CHGA; rodent, Chga) along with catecholamines, neuropeptides and adenosine triphosphate (ATP). CHGA serves as a pro-protein and upon proteolytic cleavage it generates active peptides, including catestatin (human CHGA352-372), first discovered in adrenal medullary chromaffin granules. Studies in our laboratory demonstrated that catestatin acts at the nicotinic acetylcholine receptor to inhibit catecholamine secretion. However, the specificity of catestatin to exert nicotinic-cholinergic antagonism among its co-transmitters is not clearly known, nor is the potential effect of catestatin on multiple vesicle co-transmitters understood. AIM: Here we probed the specificity of catestatin's actions among its co-transmitters: catecholamines, ATP, and neuropeptide Y (NPY). METHODS: We studied the effects of each transmitter on exocytotic secretion of its co-transmitters from PC12 chromaffin cells, stimulating secretion by triggering physiological pathways at multiple sites. RESULTS: We observed that, among chromaffin granule co-transmitters, only catestatin and NPY inhibited catecholamine release induced by nicotinic-cholinergic stimulation; catestatin was more than tenfold more potent than NPY in this setting. We also stimulated norepinephrine secretion by other chromaffin cell agonists: catestatin blocked norepinephrine release induced by nicotine, but not by other agents (such as membrane depolarization) acting at later stages in the secretory pathway, nor by agents acting on other receptor classes. By contrast, NPY acted less specifically, blocking norepinephrine release triggered by either nicotine or membrane depolarization. Catestatin inhibited nicotinic-cholinergic co-release of all classes of chromaffin granule co-transmitters: catecholamines, chromogranins, neuropeptides, and ATP. Naturally occurring variants of human catestatin (Gly364Ser and Pro370Leu) exhibited parallel changes in potency to inhibit secretion of catecholamines and ATP. CONCLUSION: We conclude that, among the chromaffin granule co-transmitters, catestatin acts as the most specific and potent inhibitor of physiological pathway (nicotinic-cholinergic) stimulated secretion. Furthermore, catestatin generally inhibits nicotinically triggered exocytotic release of multiple co-transmitters from chromaffin granules. The results have physiological and pharmacological implications for co-transmission in the sympathochromaffin system.

Changes in vasoconstrictor and vasodilator neurotransmitters in nerves supplying arterioles in developing colorectal polyps.

OBJECTIVE: To examine the changes that occur in the immunohistochemistry of vasoconstrictor and vasodilator transmitters in nerves supplying early and advanced colorectal polyps. SUBJECTS AND METHODS: We studied the perivascular innervation of submucosal arterioles of colorectal polyps (n = 18) and the innervation of the epithelial layer of polyps compared to normal controls (n=8), using immunohistochemical markers for the neurotransmitters; noradrenaline (NA) (marker used; tyrosine hydroxylase (TH)), neuropeptide Y (NPY), vasoactive intestinal polypeptide (VIP), substance P (SP), and calcitonin gene-related polypeptide (CGRP). (Advanced polyps; villous adenomas>1.5 cm, polyps with severe dysplasia or partial carcinoma). RESULTS: In submucosal arterioles there was a progressive decrease from controls through early polyps to advanced polyps in TH and NPY perivascular immunoreactivity (P<0.015 for both). VIP and SP immunoreactivity was higher in early polyps compared to controls, but markedly reduced in advanced polyps (P<0.05 for VIP). Sparse CGRP immunoreactivity was present in polyps only. Neural VIP and SP immunoreactivity in the lamina propria of polyp mucosa was more intense than in controls. CONCLUSION: There is a decrease in vasoconstrictor neurotransmitters NPY and NA (shown by TH) around submucosal arterioles of both early and advanced polyps, but an increase in the vasodilator neurotransmitters, particularly VIP, in early colorectal polyps. These results suggest a predominantly vasodilatory neural influence in early polyps, perhaps indicating a mechanism that maintains polyp growth.

Increased CRF-like and NPY-like immunoreactivity in adult rats exposed to nicotine during adolescence: relation to anxiety-like and depressive-like behavior.

OBJECTIVE: Recently, animal models have been developed that demonstrate that adolescent nicotine exposure produces neurobehavioral changes which persist into adulthood. This study further examined the impact of adolescent nicotine exposure on anxiety-like and depressive-like behavior, as well as on levels of corticotropin-releasing factor (CRF) and neuropeptide Y (NPY) in this model. METHODS: Male adolescent rats (35-40 days old) were administered nicotine using Nicoderm CQ patches (Smith-Kline Beecham). Behavior in the elevated plus maze (EPM) and forced swim test (FST) was assessed 2-3 weeks after exposure ended. Brain levels of CRF and NPY were then assessed 5-6 weeks after behavioral tests were completed. In addition, blood and brain levels of nicotine resulting from nicotine treatment were examined. RESULTS: After 5 days of exposure to 5 mg/kg/day nicotine, blood levels of nicotine averaged 66+/-5 ng/ml and brain nicotine levels averaged 52+/-4 ng/g. Rats exposed to nicotine displayed an anxiety-like profile in the EPM (i.e., decreased time spent in the open arms) and an antidepressant-like profile in the FST (i.e., less time spent immobile). Rats exposed to nicotine also had increased hypothalamic and frontal cortical CRF, increased hypothalamic and hippocampal NPY, and a decreased ratio of NPY to CRF in the amygdala. CONCLUSIONS: This study demonstrates that adolescent nicotine exposure produces lasting increases in anxiety-like behavior and may reduce depressive-like behavior. These behavioral changes also occurred in concert with alterations in CRF and NPY systems. Thus, lasting neurobehavioral changes associated with adolescent nicotine exposure may be related to allostatic changes in stress peptide systems.