Central action of adrenomedullin to prevent ethanolinduced gastric injury through vagal pathways in rats

1998 ◽  
Vol 274 (6) ◽  
pp. R1783-R1788 ◽  
Author(s):  
Hiroshi Kaneko ◽  
Terunori Mitsuma ◽  
Hirofumi Nagai ◽  
Shozaburo Mori ◽  
Takashi Iyo ◽  
...  
Keyword(s):  
Wistar Rats ◽  
Protective Action ◽  
Gastric Injury ◽  
Central Action ◽  
Gastric Lesions ◽  
Protective Mechanisms ◽  
Calcitonin Gene ◽  
Intracisternal Injection ◽  
Specific Receptors ◽  
The Brain

Adrenomedullin (AM), belongs to the calcitonin gene-related peptide (CGRP) family and interacts with AM and CGRP1 receptors. Specific AM receptors and immunoreactivity are present in the rat brain. The effect of intracisternal injection of rat AM on ethanol-induced gastric lesions was studied in conscious Wistar rats. The peptide was injected intracisternally or intravenously under short anesthesia 20 min before intragastric injection of 70% ethanol. Corpus lesions were determined 1 h after ethanol. Intracisternal AM (75, 150, and 300 pmol) dose-dependently inhibited ethanol-induced gastric lesions by 40–72% and rat α-CGRP (150 pmol ic) by 76%. Intravenous AM (300 pmol) had no effect. The CGRP1 receptor antagonist CGRP-(8—37) (9.6–19.2 nmol ic) dose-dependently inhibited the protective effect of intracisternal α-CGRP but not that of AM. Subdiaphragmatic vagotomy and peripheral injection of atropine, indomethacin, or N G-nitro-l-arginine methyl ester (l-NAME) prevented AM protective action. l-Arginine but not d-arginine blockedl-NAME action. These data suggest that both AM and CGRP act in the brain to prevent ethanol-induced gastric lesions through interaction with their specific receptors. AM action may involve vagal cholinergic-dependent modulation of prostaglandins and nitric oxide protective mechanisms.

scholarly journals Actions of crude hydroalcoholic extract of Pfaffia sp on gastrointestinal tract

2003 ◽  
Vol 46 (3) ◽  
pp. 355-360 ◽  
Author(s):  
Cristina Setim Freitas ◽  
Maria Fernanda Rodrigues de Paula ◽  
Lia Rieck ◽  
Maria Consuelo Andrade Marques
Keyword(s):  
Gastrointestinal Tract ◽  
Acid Secretion ◽  
Restraint Stress ◽  
Wistar Rats ◽  
Protective Action ◽  
Folk Medicine ◽  
Gastric Lesions ◽  
Hydroalcoholic Extract ◽  
Female Wistar Rats ◽  
Duodenal Lumen

The plants that compound the Pfaffia genus are used in folk medicine to treat gastric disturbances. This study examined the effects of a crude hydroalcoholic extract of Pfaffia sp on the gastrointestinal tract. Female Wistar rats were pretreated orally (p.o.) with the hydroalcoholic extract of Pfaffia (0.5, 1 and 2 g.kg-1) before the induction of ulcer with hypothermic restraint stress (HRS), ethanol (ET) or indomethacin (IND). Control animals received water (C) or ranitidine (60mg/kg) p.o. The hydroalcoholic extract of Pfaffia (0.5, 1 and 2 mg.kg-1) protected rats against HRS and ET - induced ulcers, but was not able to protect the gastric mucosa against IND - induced ulcers. When injected into the duodenal lumen, the hydroalcoholic extract of Pfaffia inhibited basal and stimulated acid secretion in pylorus-ligated rats. These results indicate that this plant has a protective action against gastric lesions of the mucosa involving the reduction of gastric acid secretion.

Mechanisms by which endogenous glucocorticoid protects against indomethacin-induced gastric injury in rats

2002 ◽  
Vol 283 (5) ◽  
pp. G1082-G1089 ◽  
Author(s):  
Ludmila Filaretova ◽  
Akiko Tanaka ◽  
Tohru Miyazawa ◽  
Shinichi Kato ◽  
Koji Takeuchi
Keyword(s):  
Gastric Motility ◽  
Protective Action ◽  
Microvascular Permeability ◽  
Gastric Injury ◽  
Functional Disorders ◽  
Gastric Lesions ◽  
Inhibitory Effects ◽  
Glucose Levels ◽  
Blood Glucose Levels ◽  
Adrenalectomized Rats

We investigated the mechanisms underlying the protective action of glucocorticoids against indomethacin-induced gastric lesions. One-week adrenalectomized rats with or without corticosterone replacement (4 mg/kg sc) were administered indomethacin (25 mg/kg sc), and gastric secretion (acid, pepsin, and mucus), motility, microvascular permeability, and blood glucose levels were examined. Indomethacin caused gastric lesions in sham-operated rats, with an increase in gastric motility and microvascular permeability as well as a decrease in mucus secretion. Adrenalectomy significantly worsened the lesions and potentiated these functional disorders. Glucose levels were lowered by indomethacin in sham-operated rats, and this response was enhanced by adrenalectomy. The changes observed in adrenalectomized rats were prevented by supplementations of corticosterone at a dose mimicking the indomethacin-induced rise in corticosterone, whereas the protective effect of corticosterone was attenuated by RU-38486, a glucocorticoid receptor antagonist. We conclude that the gastroprotective action of endogenous glucocorticoids may be provided by their support of glucose homeostasis and inhibitory effects on enhanced gastric motility and microvascular permeability as well as maintaining the production of mucus.

Intracisternal PYY increases gastric mucosal resistance: role of cholinergic, CGRP, and NO pathways

1999 ◽  
Vol 277 (3) ◽  
pp. G555-G562 ◽  
Author(s):  
Hong Yang ◽  
Keishi Kawakubo ◽  
Yvette Taché
Keyword(s):  
Peptide Yy ◽  
Antisense Oligodeoxynucleotide ◽  
Intragastric Administration ◽  
Gastric Lesions ◽  
Protective Mechanisms ◽  
Gastroprotective Effect ◽  
Calcitonin Gene ◽  
Cgrp Receptor Antagonist ◽  
Synthase Inhibitor

The influence of intracisternal injection of peptide YY (PYY) on gastric lesions induced by ethanol was studied in urethan-anesthetized rats. Gastric lesions covered 15–22% of the corpus as monitored 1 h after intragastric administration of 45% ethanol (5 ml/kg) in intracisternal vehicle control groups. PYY, at doses of 23, 47, or 117 pmol 30 min before ethanol, decreased gastric lesions by 27%, 63%, and 59%, respectively. Thyrotropin-releasing hormone (TRH) receptor antisense oligodeoxynucleotide pretreatment (intracisternally, 48 and 24 h before intracisternal PYY) did not influence the gastroprotective effect of intracisternal PYY (47 pmol) but abolished that of intracisternal TRH analog RX-77368 (4 pmol). RX-77368 (2.6 pmol) and PYY (6 pmol) were ineffective when injected intracisternally alone but reduced ethanol lesions by 44% when injected simultaneously. Atropine (subcutaneously), the calcitonin gene-related peptide (CGRP) receptor antagonist CGRP-(8—37) (intravenously), or the nitric oxide (NO) synthase inhibitor N G-nitro-l-arginine methyl ester (l-NAME, intravenously) completely abolished the gastroprotective effect of intracisternal PYY (47 pmol), whereas indomethacin (intraperitoneally) had no effect. The l-NAME action was reversed by l-arginine but not by d-arginine (intravenously). These results suggest that intracisternal PYY acts independently of medullary TRH to decrease ethanol-induced gastric lesions. The PYY action involves vagal cholinergic-mediated CGRP/NO protective mechanisms.

scholarly journals 0.1T magnetic resonance image in the study of experimental hydrocephalus in rats. Accuracy of the method in the measurements of the ventricular size

2012 ◽  
Vol 27 (11) ◽  
pp. 768-772 ◽  
Author(s):  
Samuel Caputo de Castro ◽  
Hélio Rubens Machado ◽  
Carlos Henrique Rocha Catalão ◽  
Betina Aisengart de Siqueira ◽  
Ana Leda Bertoncini Simões ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Magnetic Resonance Image ◽  
Wistar Rats ◽  
Ventricular Size ◽  
Resonance Imaging ◽  
Experimental Hydrocephalus ◽  
Intracisternal Injection ◽  
The Difference ◽  
Magnetic Resonance Imaging Mri ◽  
The Brain

PURPOSE: To investigate the accuracy of 1.0T Magnetic Resonance Imaging (MRI) to measure the ventricular size in experimental hydrocephalus in pup rats. METHODS: Wistar rats were subjected to hydrocephalus by intracisternal injection of 20% kaolin (n=13). Ten rats remained uninjected to be used as controls. At the endpoint of experiment animals were submitted to MRI of brain and killed. The ventricular size was assessed using three measures: ventricular ratio (VR), the cortical thickness (Cx) and the ventricles area (VA), performed on photographs of anatomical sections and MRI. RESULTS: The images obtained through MR present enough quality to show the lateral ventricular cavities but not to demonstrate the difference between the cortex and the white matter, as well as the details of the deep structures of the brain. There were no statistically differences between the measures on anatomical sections and MRI of VR and Cx (p=0.9946 and p=0.5992, respectively). There was difference between VA measured on anatomical sections and MRI (p<0.0001). CONCLUSION: The parameters obtained through 1.0T MRI were sufficient in quality to individualize the ventricular cavities and the cerebral cortex, and to calculate the ventricular ratio in hydrocephalus rats when compared to their respective anatomic slice.

Vagal mechanisms underlying gastric protection induced by chemical activation of raphe pallidus in rats

1998 ◽  
Vol 275 (5) ◽  
pp. G1056-G1062 ◽  
Author(s):  
Hiroshi Kaneko ◽  
Jonathan Kaunitz ◽  
Yvette Taché
Keyword(s):  
Acid Secretion ◽  
Kainic Acid ◽  
Chemical Activation ◽  
Mucosal Blood Flow ◽  
Gastric Mucosal Blood Flow ◽  
Inhibitory Effect ◽  
Gastric Injury ◽  
Gastric Lesions ◽  
Calcitonin Gene ◽  
Raphe Pallidus

Peripheral mechanisms involved in kainic acid injected into the raphe pallidus (Rpa)-induced gastric protection were investigated in urethan-anesthetized rats. Gastric mucosal blood flow (GMBF), acid secretion, and gastric injury induced by intragastric ethanol (60%) were measured in response to kainic acid (25 pg) injected into the Rpa. Kainic acid reduced ethanol-induced gastric lesions by 57%. The protective effect was blocked by vagotomy, capsaicin deafferentation, and intravenous injection of the calcitonin gene-related peptide (CGRP) antagonist CGRP-(8—37) and NG-nitro-l-arginine methyl ester (l-NAME).l- but notd-arginine reversed thel-NAME action. Kainic acid injected into the Rpa, unlike outside sites, increased basal GMBF but not acid secretion. Indomethacin unmasked an acid secretory response to kainic acid. These results show that kainic acid injected into the Rpa at a dose that did not stimulate acid secretion, due to the inhibitory effect of prostaglandins, protects against ethanol-induced gastric injury through vagal-dependent activation of CGRP contained in capsaicin-sensitive afferents and nitric oxide-mediated gastric vasodilatory mechanisms.

Polychlorinated biphenyl induced hepatocyte alterations

1987 ◽  
Vol 45 ◽  
pp. 716-717
Author(s):  
D.N. Collins ◽  
J.N. Turner ◽  
K.O. Brosch ◽  
R.F. Seegal
Keyword(s):  
Lipid Droplets ◽  
Wistar Rats ◽  
Homovanillic Acid ◽  
Polychlorinated Biphenyl ◽  
Corn Oil ◽  
Environmental Pollutants ◽  
Short Term ◽  
Pcb Congeners ◽  
Urinary Levels ◽  
The Brain

Polychlorinated biphenyls (PCBs) are a ubiquitous class of environmental pollutants with toxic and hepatocellular effects, including accumulation of fat, proliferated smooth endoplasmic recticulum (SER), and concentric membrane arrays (CMAs) (1-3). The CMAs appear to be a membrane storage and degeneration organelle composed of a large number of concentric membrane layers usually surrounding one or more lipid droplets often with internalized membrane fragments (3). The present study documents liver alteration after a short term single dose exposure to PCBs with high chlorine content, and correlates them with reported animal weights and central nervous system (CNS) measures. In the brain PCB congeners were concentrated in particular regions (4) while catecholamine concentrations were decreased (4-6). Urinary levels of homovanillic acid a dopamine metabolite were evaluated (7).Wistar rats were gavaged with corn oil (6 controls), or with a 1:1 mixture of Aroclor 1254 and 1260 in corn oil at 500 or 1000 mg total PCB/kg (6 at each level).

Activation of astroglial CB1R mediates cerebral ischemic tolerance induced by electroacupuncture

2021 ◽  
pp. 0271678X2199439
Author(s):  
Cen Yang ◽  
Jingjing Liu ◽  
Jingyi Wang ◽  
Anqi Yin ◽  
Zhenhua Jiang ◽  
...  
Keyword(s):  
Endocannabinoid System ◽  
Artery Occlusion ◽  
Ischemic Tolerance ◽  
Protective Mechanisms ◽  
Promising Therapeutic Approach ◽  
Subsequent Activation ◽  
Cerebral Ischemic ◽  
Cerebral Artery Occlusion ◽  
The Brain

There are no effective treatments for stroke. The activation of endogenous protective mechanisms is a promising therapeutic approach, which evokes the intrinsic ability of the brain to protect itself. Accumulated evidence strongly suggests that electroacupuncture (EA) pretreatment induces rapid tolerance to cerebral ischemia. With regard to mechanisms underlying ischemic tolerance induced by EA, many molecules and signaling pathways are involved, such as the endocannabinoid system, although the exact mechanisms have not been fully elucidated. In the current study, we employed mutant mice, neuropharmacology, microdialysis, and virus transfection techniques in a middle cerebral artery occlusion (MCAO) model to explore the cell-specific and brain region-specific mechanisms of EA-induced neuroprotection. EA pretreatment resulted in increased ambient endocannabinoid (eCB) levels and subsequent activation of ischemic penumbral astroglial cannabinoid type 1 receptors (CB1R) which led to moderate upregulation of extracellular glutamate that protected neurons from cerebral ischemic injury. These findings provide a novel cellular mechanism of EA and a potential therapeutic target for ischemic stroke.

scholarly journals Modafinil Effects on Behavior and Oxidative Damage Parameters in Brain of Wistar Rats

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Felipe Ornell ◽  
Samira S. Valvassori ◽  
Amanda V. Steckert ◽  
Pedro F. Deroza ◽  
Wilson R. Resende ◽  
...  
Keyword(s):  
Oxidative Damage ◽  
Open Field ◽  
Wistar Rats ◽  
Thiobarbituric Acid ◽  
Protein Carbonyl ◽  
Behavioral Changes ◽  
Protein Damage ◽  
Behavioral Parameters ◽  
Carbonyl Formation ◽  
The Brain

The effects of modafinil (MD) on behavioral and oxidative damage to protein and lipid in the brain of rats were evaluated. Wistar rats were given a single administration by gavage of water or MD (75, 150, or 300 mg/kg). Behavioral parameters were evaluated in open-field apparatus 1, 2, and 3 h after drug administration. Thiobarbituric acid reactive substances (TBARS) and protein carbonyl formation were measured in the brain. MD increased locomotor activity at the highest dose 1 and 3 h after administration. MD administration at the dose of 300 mg/kg increased visits to the center of open-field 1 h after administration; however, 3 h after administration, all administered doses of MD increased visits to the open-field center. MD 300 mg/kg increased lipid damage in the amygdala, hippocampus, and striatum. Besides, MD increased protein damage in the prefrontal cortex, amygdala, and hippocampus; however, this effect varies depending on the dose administered. In contrast, the administration of MD 75 and 300 mg/kg decreased the protein damage in the striatum. This study demonstrated that the MD administration induces behavioral changes, which was depending on the dose used. In addition, the effects of MD on oxidative damage parameters seemed to be in specific brain region and doses.

IMMUNOHISTOCHEMICAL STUDIES OF BLOOD BRAIN BARRIER AFTER ADMINISTRATION OF ABHRAK BHASM IN WISTAR RATS

2021 ◽  
pp. 13-19
Author(s):  
Amita Singh ◽  
Raj Kumar ◽  
S. K. Kannaujia ◽  
Manikrishna Manikrishna ◽  
N. P. Singh
Keyword(s):  
Blood Brain Barrier ◽  
Wistar Rats ◽  
Brain Parenchyma ◽  
Brain Barrier ◽  
Major Constituent ◽  
Control Group ◽  
Blood Brain ◽  
Biological Studies ◽  
Immunohistochemical Studies ◽  
The Brain

Abhrak bhasma (AB) is a type of bhasma prepared from repeated incineration of mineral mica with decoctions of about 72 herbs. The particle size of Abhrak bhasm has been shown to be in the range of 29-88 nanometers and Fe, Ca, Si, Mg and K are found to be as major constituent. Many drugs developed to treat Central Nervous System (CNS) disorders are unable to reach the brain parenchyma in therapeutically relevant concentrations. The blood brain barrier protects brain parenchyma from the uctuation of plasma composition, from pathogenic agents and maintains homeostasis of the brain parenchyma by restricting non-specic ux of ions, peptides, proteins and even cells into and out the brain. Immunohistochemistry is being widely employed as a tool for biological studies. This study is conducted to examine the change in the continuity of Blood brain barrier by using immunohistochemistry, once Abhrak bhasm drug is given in experimental animal and also to examine the histology of organs. In this study a total of 30 adult albino Wistar rats of approximately 4 months age (approx. 150-200 gms) of either sex selected randomly to see the effect of Abhrak bhasm, an ayurvedic drug on Wistar rats. The rats were weighed, marked and divided into 5 groups each consisting of six animals. In normal control group (Group E), no drug was administered and in rest of the four treated groups (Group-A,B,C,D), Abhrak bhasm @ 36 mg/kg B.wt. was administered orally once in each rat. Brain, liver, kidneys,spleen and blood samples were collected in 10% formalin solution after euthanizing the rats at 0.5,2,6 & 12 hours of Abhrak bhasma drug intervention. The alterations in any of the biochemical parameters are within the tolerable limits of liver and kidney since the dose of abhrak bhasm did not affect liver and kidneys. In the present study, the increase in ALP level may be the result of alterations in metabolisms that occurred without any signicant alteration in histology of liver. After applying the immunohistochemistry with the research markers GFAP, CD 34, S 100, GLUT-1 and RECA-1 on the rats in groups A,B,C and D, there was no change in the intensity of immunohistochemistry, with respect to control. While on applying the Occludin, the intensity of immunohistochemistry was reduced in all the treatment groups as compared to the control group. On the basis of ndings of present study it can be concluded that the therapeutic dose of Abhrak bhasma causes changes at the level of tight junctions present in blood brain barrier in rats which is shown by immunohistochemistry with occludin research marker. There is no toxic effect of drug on different organs of rats as no signicant changes in histology of organs are seen. More studies need to be done to check the permeability of blood brain barrier for Abhrak bhasma drug, like calculating its concentration in brain tissues and other vital organs of rat.

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