astressin-2b and antalarmin

Ischemic stroke is the second leading cause of death worldwide. Therefore, exploring effective and emerging molecular targets for ischemic stroke is a primary task of basic and clinical research. The aim of the present study was to investigate the function of corticotropin-releasing factor (CRF) in ischemic stroke and its related mechanisms, to provide a reference for the treatment of ischemic stroke. CRF, antalarmin, or astressin-2B were used to activate or block the CRF1 (CRF receptor 1) or CRF2 (CRF receptor 2) in BV2 cells and adult male mice, thus constructing a distal middle cerebral artery occlusion (dMCAO) model. CRF not only accelerated microglial activity by promoting transcription and production of inflammatory factors, but also promoted the transformation of activated BV2 cells from a neuroprotective phenotype (M2) to cytotoxic phenotype (M1), and these effects were mediated by the TLR4/NF-κB signaling pathway. These effects can be blocked by antalarmin but not by astressin-2B. CRF significantly aggravated the neurological deficit, increased infarction volume, and exacerbated neuronal injuries. Additionally, CRF significantly improved the levels of TNF-α and phospho-NF-κB in the ischemia penumbra. Finally, CRF significantly increased the number of CD16/Iba-1-positive cells and decreased the number of CD206/Iba-1-positive cells in the ischemia penumbra. These results provide evidence of the proinflammatory role of CRF in an ischemic stroke model and a possible underlying mechanism, which may facilitate the elucidation of potential treatment approaches for ischemic stroke.

Topics: Animals; Corticotropin-Releasing Hormone; Disease Models, Animal; Inflammation; Ischemic Stroke; Male; Mice; Microglia; Neurons; NF-kappa B; Peptide Fragments; Peptides, Cyclic; Phosphorylation; Pyrimidines; Pyrroles; Receptors, Corticotropin-Releasing Hormone

The aim of our study was to determine the role of corticotropin-releasing factor (CRF), the urocortins (Ucn1, Ucn2 and Ucn3) and their receptors (CRF

Topics: Animals; Behavior, Animal; Corticotropin-Releasing Hormone; Male; Mice; Peptide Fragments; Peptides, Cyclic; Pyrimidines; Pyrroles; Receptors, Corticotropin-Releasing Hormone; Social Behavior; Urocortins

Corticotropin-releasing hormone release is the final common pathway of stress-associated neuroendocrine responses. This study tested how corticotropin-releasing hormone modulates airway vagal preganglionic neurons. Airway vagal preganglionic neurons in neonatal rats were retrogradely labeled with fluorescent dye and identified in medullary slices, and their responses to corticotropin-releasing hormone (200nmolL

Topics: 6-Cyano-7-nitroquinoxaline-2,3-dione; Animals; Animals, Newborn; Autonomic Fibers, Preganglionic; Bicuculline; Corticotropin-Releasing Hormone; Excitatory Amino Acid Antagonists; Excitatory Postsynaptic Potentials; Female; GABA-A Receptor Antagonists; Male; Medulla Oblongata; Neurons; Peptide Fragments; Peptides, Cyclic; Pyrimidines; Pyrroles; Rats; Rats, Sprague-Dawley; Receptors, Corticotropin-Releasing Hormone; Sodium Channel Blockers; Synapses; Tetrodotoxin; Vagus Nerve

Recent studies have provided convincing evidences for co-morbidity between opioid addiction and obsessive-compulsive disorder (OCD), and the involvement of the corticotrophin-releasing factor (CRF) in the effects of morphine-withdrawal. Some scanty evidences also point towards the role of CRF in OCD and related disorders. But, no evidence indicated the role of CRF in morphine withdrawal associated obsessive-compulsive behavior (OCB). Therefore, the present study investigated the role of CRF in morphine-withdrawal induced OCB in mice. Marble-burying behavior in mice was used to assess OCB as this model has good predictive and face validity. The results revealed that acute morphine dose dependently attenuated the marble burying behavior, whereas withdrawal of chronic morphine was associated with significant rise in marble burying behavior. This indicates the differential effect of acute morphine and chronic morphine-withdrawal on OCB. Further, acute treatment with CRF receptor antagonists like antalarmin (2 and 4 μg/mouse, i.c.v.) or astressin-2B (3 and 10 nmol/mouse, i.c.v.) dose dependently attenuated the peak morphine-withdrawal induced increase in marble burying behavior. Moreover, concomitant treatment with antalarmin (4 μg/mouse, i.c.v.) or astressin-2B (10 nmol/mouse, i.c.v.) along with morphine blocked the morphine-withdrawal associated exacerbation of OCB. These results indicate that OCB associated with morphine withdrawal state is partly mediated by the activation of central CRF receptors.

Topics: Animals; Behavior, Animal; Disease Models, Animal; Dose-Response Relationship, Drug; Male; Mice; Morphine; Motor Activity; Narcotics; Obsessive-Compulsive Disorder; Peptide Fragments; Peptides, Cyclic; Pyrimidines; Pyrroles; Receptors, Corticotropin-Releasing Hormone; Substance Withdrawal Syndrome

CRH and its related peptides urocortins (UCN) have been identified in placenta and implicated to play pivotal roles in the regulation of pregnancy and parturition in humans. The objectives of present study were to investigate the effects of endogenous CRH and its related peptides in the regulation of steroid production in placenta. Placental trophoblasts were isolated from term placenta tissues and cultured for 72 h. Estradiol (E(2)) and progesterone (P(4)) contents in culture media were determined by radioimmunoassay. Treatment of cultured trophoblasts with CRH or UCNI antibody showed decreased E(2), whereas increased P(4) production. Treatment of cells with CRH receptor type 1 antagonist antalarmin or CRH receptor type 2 (CRH-R2) antagonist astressin-2b also decreased E(2) but increased P(4) production. Knockdown of CRH receptor type 1 or CRH-R2 cells showed a decrease in E(2) production and an increase in P(4) production. In CRH-R2 knockdown cells, CRH stimulated GTP-bound Gαs protein and phosphorylated phospholipase C-β3. Adenylyl cyclase and protein kinase A inhibitors blocked CRH-induced increased E(2) production but not decreased P(4) production. PLC inhibitor U73122 and protein kinase C inhibitor chelerythrine blocked the effects of CRH on E(2) and P(4) production in CRH-R2 knockdown cells. UCNIII, the specific CRH-R2 agonist, stimulated GTP-bound Gαi protein and phosphorylated phospholipase C-β3 expression. Both U73122 and chelerythrine blocked UCNIII-induced increased E(2) production and decreased P(4) production. We suggest that CRH and its related peptides might be involved in changes in the progesterone to estrogen ratio during human pregnancy.

Topics: Adult; Benzophenanthridines; Cells, Cultured; Enzyme Inhibitors; Estradiol; Estrenes; Female; Humans; Peptide Fragments; Peptides, Cyclic; Placenta; Pregnancy; Progesterone; Protein Kinase C; Pyrimidines; Pyrroles; Pyrrolidinones; Receptors, Corticotropin-Releasing Hormone; Signal Transduction; Trophoblasts

CRH has been implicated as a mediator of stress-induced effects on the hypothalamus-pituitary-gonad axis, acting via CRH receptors in various brain regions. We investigated whether the effects of restraint stress on the secretion of gonadotropins on the morning of proestrus are mediated by the CRH-R1 or CRH-R2 receptors in the oval subdivision of the anterolateral BST, the central amygdala, the locus coeruleus (LC), or the A1 and A2 neuron groups in the medulla. At proestrus morning, rats were injected with antalarmin (a CRH-R1 antagonist), asstressin2-B (a CRH-R2 antagonist) or vehicles. Thirty minutes after the injection, the animals were placed into restraints for 30 min, and blood was sampled for 2 h. At the end of the experiment, the brains were removed for immunofluorescence analyses. Restraint stress increased the levels of FSH and LH. Antalarmin blocked the stress-induced increases in FSH and LH secretion, but astressin2-B only blocked the increase in FSH secretion. LC showed intense stress-induced neuronal activity. FOS/tyrosine-hydroxylase coexpression in LC was reduced by antalarmin, but not astressin2-B. The CRH-R1 receptor, more than CRH-R2 receptor, appears to be essential for the stimulation of the hypothalamus-pituitary-gonad axis by acute stress; this response is likely mediated in part by noradrenergic neurons in the LC. We postulate that the stress-induced facilitation of reproductive function is mediated, at least in part, by CRH action through CRH-R1 on noradrenaline neurons residing in the LC that trigger GnRH discharge and gonadotropin secretion.

Topics: Animals; Corticotropin-Releasing Hormone; Female; Follicle Stimulating Hormone; Locus Coeruleus; Luteinizing Hormone; Neurons; Peptide Fragments; Peptides, Cyclic; Proestrus; Pyrimidines; Pyrroles; Rats; Rats, Wistar; Receptors, Corticotropin-Releasing Hormone; Restraint, Physical; Stress, Physiological; Tyrosine 3-Monooxygenase

Stressful events are determinants of relapse in recovering cocaine addicts. Excessive cocaine use may increase susceptibility to stressor-induced relapse through alterations in brain corticotropin-releasing factor (CRF) regulation of neurocircuitry involved in drug seeking. We previously reported that the reinstatement of cocaine seeking by a stressor (footshock) is CRF dependent and is augmented in rats that self-administered cocaine under long-access (LgA; 6 h daily) conditions for 14 d when compared with rats provided shorter daily cocaine access [short access (ShA) rats; 2 h daily]. Further, we have demonstrated that reinstatement in response to intracerebroventricular CRF administration is heightened in LgA rats. This study examined the role of altered ventral tegmental area (VTA) responsiveness to CRF in intake-dependent increases in CRF- and stress-induced cocaine seeking. Bilateral intra-VTA administration of CRF (250 or 500 ng/side) produced reinstatement in LgA but not ShA rats. In LgA rats, intra-VTA CRF-induced reinstatement was blocked by administration of the CRF-receptor type 1 (CRF-R1) antagonist antalarmin (500 ng/side) or CP-376395 (500 ng/side), but not the CRF-R2 antagonist astressin-2B (500 ng or 1 μg/side) or antisauvagine-30 (ASV-30; 500 ng/side) into the VTA. Likewise, intra-VTA antalarmin, but not astressin-2B, blocked footshock-induced reinstatement in LgA rats. By contrast, neither intra-VTA antalarmin nor CP-376395 altered food-reinforced lever pressing. Intra-VTA injection of the CRF-R1-selective agonist cortagine (100 ng/side) but not the CRF-R2-selective agonist rat urocortin II (rUCN II; 250 ng/side) produced reinstatement. These findings reveal that excessive cocaine use increases susceptibility to stressor-induced relapse in part by augmenting CRF-R1-dependent regulation of addiction-related neurocircuitry in the VTA.

Topics: Aminopyridines; Analysis of Variance; Animals; Behavior, Addictive; Behavior, Animal; Cocaine; Conditioning, Operant; Corticotropin-Releasing Hormone; Dopamine Uptake Inhibitors; Dose-Response Relationship, Drug; Drug Synergism; Extinction, Psychological; Flavonoids; Food Preferences; Glucosides; Male; Peptide Fragments; Peptides, Cyclic; Pyrimidines; Pyrroles; Rats; Rats, Sprague-Dawley; Receptors, Corticotropin-Releasing Hormone; Reinforcement, Psychology; Self Administration; Stress, Psychological; Ventral Tegmental Area

In this study, we tested the effect of urocortin 1 (Ucn1) on the contractility of gallbladder smooth muscle (GBSM) strips from guinea pigs and studied the involvement of corticotropin-releasing factor (CRF) receptors in this effect. The effect of Ucn1 on the isometric contractions of non-contracted and acetylcholine (Ach)-contracted GBSM, and the effects of CRF-R antagonists antalarmin and astressin 2B on the effect of Ucn1 were studied. In addition, the expression of receptors for CRF-R1 and CRF-R2 in guinea pig gallbladder were investigated using reverse transcription - polymerase chain reaction (RT-PCR). Ucn1 dose-dependently inhibited the contractility of GBSM. Moreover, Ucn1 decreased the resting tension, the mean contractile amplitude, and the contractile frequency in both non-contracted and Ach-contracted strips of GBSM. Furthermore, Ucn1 induced rightward shift of the Ach concentration-response curve of Ach in Ach-contracted strips. This inhibitory effect of Ucn1 on both non-contracted and Ach-contracted strips was inhibited by astressin 2B, but not by antalarmin. RT-PCR demonstrated that the CRF-R2, but not CRF-R1 receptor subtype is expressed in the muscularis muscle of guinea pig gallbladder. In conclusion, Ucn1 has an inhibitory effect on the contractility of GBSM of guinea pig, mediated through stimulating CRF-R2 receptors in GBSM. More studies are needed to clarify the intracellular signaling events involved in this effect.

Topics: Acetylcholine; Animals; DNA, Complementary; Dose-Response Relationship, Drug; Drug Evaluation, Preclinical; Gallbladder; Guinea Pigs; In Vitro Techniques; Male; Muscle Contraction; Muscle, Smooth; Muscles; Peptide Fragments; Peptides, Cyclic; Pyrimidines; Pyrroles; Receptors, Corticotropin-Releasing Hormone; Signal Transduction; Urocortins

Local or 'Immune' Corticotropin-Releasing Hormone (CRH) is secreted in peripheral tissues and plays a direct immunomodulatory role as an endocrine or paracrine mediator of inflammation. The present study was undertaken to determine whether CRH affects the endothelial redox state. Accordingly, intracellular reactive oxygen species (ROS) content and peroxynitrite levels, endothelial nitric oxide synthase (eNOS) activity and nitric oxide (NO) levels as well as catalase activity, superoxide dismutase (SOD) activity and glutathione (GSH) levels were measured in the presence or absence of selective CRH receptor-1 and CRH receptor-2 inhibitors in endothelial EAhy926 cells exposed in vitro in 10(-7) M CRH for 2 h. CRH acting through both receptors induced a significant increase of ROS content (p < 0.001), catalase activity (p < 0.001) and SOD activity (p < 0.001), accompanied by a simultaneous significant decrease of eNOS activity and NO levels (p < 0.001), as well as a significant increase in nitrotyrosine (peroxynitrite) levels (p < 0.05). The data indicate that CRH may act as a regulator of pro-inflammatory mechanisms inducing adaptation of endothelial cell function to local stress.

Topics: Antioxidants; Catalase; Cell Line; Corticotropin-Releasing Hormone; Culture Media, Conditioned; Endothelial Cells; Glutathione; Humans; Nitrates; Nitric Oxide; Nitric Oxide Synthase Type III; Nitrites; Peptide Fragments; Peptides, Cyclic; Pyrimidines; Pyrroles; Reactive Oxygen Species; Receptors, Corticotropin-Releasing Hormone; Superoxide Dismutase; Tyrosine

The actions of neuropeptide AF (NPAF), on the hypothalamic-pituitary-adrenal (HPA) axis, behavior and autonomic functions were investigated. NPAF (0.25, 0.5, 1, 2 nmol) was administered intracerebroventricularly to rats, the behavior of which was monitored by means of telemetry, open-field (OF) observations and elevated plus-maze (EPM) tests. The temperature and heart rate were recorded by telemetry, and the plasma ACTH and corticosterone levels were used as indices of the HPA activation. The dopamine release from striatal and amygdala slices after peptide treatment (100 nM and 1 microM) was measured with a superfusion apparatus. To establish the transmission of the HPA response, animals were pretreated with the corticotrophin-releasing hormone (CRH) receptor antagonist antalarmin or astressin 2B (0.5 nmol). In the OF test, the animals were pretreated with antalarmin or haloperidol (10 microg/kg), while in the EPM test they were pretreated with antalarmin or diazepam (1 mg/kg). NPAF stimulated ACTH and corticosterone release, which was inhibited by antalarmin. It activated exploratory locomotion (square crossings and rearings) and grooming in OF observations, and decreased the entries to and the time spent in the open arms during the EPM tests. The antagonists inhibited the locomotor responses, and also attenuated grooming and the EPM responses. NPAF also increased spontaneous locomotion, and tended to decrease the core temperature and the heart rate in telemetry, while it augmented the dopamine release from striatal and amygdala slices. These results demonstrate, that acute administration of exogenous NPAF stimulates the HPA axis and behavioral paradigms through CRH and dopamine release.

Topics: Adrenocorticotropic Hormone; Animals; Anti-Anxiety Agents; Behavior, Animal; Body Temperature; Brain; Central Nervous System Agents; Corticosterone; Diazepam; Dopamine; Dopamine Antagonists; Haloperidol; Heart Rate; Hypothalamo-Hypophyseal System; In Vitro Techniques; Male; Motor Activity; Oligopeptides; Peptide Fragments; Peptides, Cyclic; Pituitary-Adrenal System; Pyrimidines; Pyrroles; Rats; Rats, Wistar; Receptors, Corticotropin-Releasing Hormone

The actions of individual corticotropin-releasing hormone (CRH) receptor (CRHR1 and CRHR2) were studied on the hyperthermia caused by urocortin 1, urocortin 2 and urocortin 3 in rats. Urocortin 1, urocortin 2 or urocortin 3 was injected into the lateral brain ventricle in conscious rats and the colon temperature was measured at different times following injection, up to 6h. In order to study the possible role of CRH receptors, the animals were treated with a urocortins together with the urocortin receptor inhibitors CRF 9-41, antalarmin and astressin 2B to influence the action of urocortins in initiating hyperthermia. Urocortin 1 at a dose of 2microg caused an increase in colon temperature, maximal action being observed in body temperature at 3h. CRH 9-41 and antalarmin, CRHR1 receptor antagonists, prevented the urocortin-induced increase in colon temperature while astressin 2B (CRHR2 receptor antagonist) was ineffective. Urocortin 2 at a dose of 2microg showed a byphasic action in increase in colon temperature having the first peak between 30 min and 1h and the second peak at 4h following treatment. CRF (9-41) and antalarmin was ineffective while astressin 2B fully blocked the action of urocortin 2. Urocortin 3 in a dose of lmicrog increased colon temperature; the maximal effect was observed at 2h. CRF (9-41) and antalarmin was ineffective while astressin 2B fully blocked the action of urocortin 3. The results demonstrated that urocortin 1, 2 or 3 when injected into the lateral brain ventricle caused increases in body temperature is mediated by urocortin receptors. The action of urocortin 1 is mediated by CRHR1 receptor, while in the action of urocortin 2 and urocortin 3 CRHR2 receptor is involved.

Topics: Animals; Body Temperature; Colon; Corticotropin-Releasing Hormone; Hyperthermia, Induced; Injections, Intraventricular; Male; Peptide Fragments; Peptides, Cyclic; Pyrimidines; Pyrroles; Rats; Rats, Wistar; Receptors, Corticotropin-Releasing Hormone; Urocortins