Effects of morphine withdrawal on catecholaminergic neurons on heart right ventricle; implication of dopamine receptors

2001 ◽  
Vol 79 (10) ◽  
pp. 885-891 ◽  
Author(s):  
M V Milanés ◽  
M T Marín ◽  
M L Laorden
Keyword(s):  
Right Ventricle ◽  
Receptor Antagonist ◽  
Dopamine Receptors ◽  
Biochemical Analysis ◽  
Sch 23390 ◽  
Receptor Activation ◽  
Morphine Withdrawal ◽  
Dopamine Turnover ◽  
Catecholaminergic Neurons ◽  
The Right

The purpose of our study was to examine the effects of D1-and D2-dopamine receptors blockade on the changes in the ventricular content of catecholamines in rats withdrawn from morphine. Rats were given morphine by subcutaneous (sc) implantation of morphine pellets for 5 days. On the eighth day, morphine withdrawal was induced by sc administration of naloxone (1 mg/kg), and rats were killed 30 min later. Pretreatment with SCH 23390 (dopamine D1, D5 receptor antagonist) 15 min prior to naloxone administration suppressed some the behavioural signs of morphine withdrawal, whereas eticlopride (dopamine D2, D3, D4 receptor antagonist) did not. In addition, biochemical analysis indicate that SCH 23390 completely abolished the withdrawal-induced increase in noradrenaline and dopamine turnover in the right ventricle. By contrast, eticlopride did not block the hyperactivity of catecholaminergic neurons in the heart during morphine withdrawal. These data suggest that the hyperactivity of catecholaminergic neurons in the heart during morphine withdrawal is dependent upon D1 dopamine receptor activation. In addition, our results exclude the involvement of D2 dopamine receptors.Key words: morphine withdrawal, right ventricle, catecholaminergic activity.

Dopamine D-1/D-5 Receptor Activation Is Required for Long-Term Potentiation in the Rat Neostriatum In Vitro

2001 ◽  
Vol 85 (1) ◽  
pp. 117-124 ◽  
Author(s):  
J.N.D. Kerr ◽  
J. R. Wickens
Keyword(s):  
Receptor Antagonist ◽  
Learning And Memory ◽  
Sch 23390 ◽  
Long Term Potentiation ◽  
Receptor Activation ◽  
Striatal Neurons ◽  
Theoretical Understanding ◽  
Endogenous Dopamine ◽  
Term Potentiation

Dopamine and glutamate are key neurotransmitters involved in learning and memory mechanisms of the brain. These two neurotransmitter systems converge on nerve cells in the neostriatum. Dopamine modulation of activity-dependent plasticity at glutamatergic corticostriatal synapses has been proposed as a cellular mechanism for learning in the neostriatum. The present research investigated the role of specific subtypes of dopamine receptors in long-term potentiation (LTP) in the corticostriatal pathway, using intracellular recording from striatal neurons in a corticostriatal slice preparation. In agreement with previous reports, LTP could be induced reliably under Mg2+-free conditions. This Mg2+-free LTP was blocked by dopamine depletion and by the dopamine D-1/D-5 receptor antagonist SCH 23390 but was not blocked by the dopamine D-2 receptor antagonist remoxipride or the GABAA antagonist picrotoxin. In dopamine-depleted slices, the ability to induce LTP could be restored by bath application of the dopamine D-1/D-5 receptor agonist, SKF 38393. These results show that activation of dopamine D-1/D-5 receptors by either endogenous dopamine or exogenous dopamine agonists is a requirement for the induction of LTP in the corticostriatal pathway. These findings have significance for current understanding of learning and memory mechanisms of the neostriatum and for theoretical understanding of the mechanism of action of drugs used in the treatment of psychotic illnesses and Parkinson's disease.

Effects of dopamine in isolated rat colon strips

2005 ◽  
Vol 83 (6) ◽  
pp. 447-452 ◽  
Author(s):  
María J Aguilar ◽  
Luis Estañ ◽  
Inocencia Martínez-Mir ◽  
Manuel Martínez-Abad ◽  
Elena Rubio ◽  
...  
Keyword(s):  
Dopamine Receptors ◽  
Sch 23390 ◽  
Distal Colon ◽  
Dopamine Antagonists ◽  
Rat Colon ◽  
Spontaneous Motility ◽  
Relaxant Response ◽  
The Right ◽  
Isolated Rat ◽  
Isolated Rat Colon

The aim of the present work is to investigate the effects of dopamine on isolated rat colon strips, and whether dopamine receptors are involved in these effects. Experiments on spontaneous motility and under potassium contraction were performed with dopamine and isoprenaline, both in the absence and presence of antagonists (distal colon strips, isotonic recording, Tyrode solution, 31 °C, 1 g of resting tension). At higher concentration (10–4mol/L), dopamine abolished spontaneous motility of the rat colon and this effect was not modified by antagonists. In isolated rat colon strips that were depolarized with potassium, dopamine produced concentration-dependent relaxation, without significant differences in reserpinized rats. Preincubation with sulpiride or Sch 23390, dopamine antagonists, did not modify the effects of dopamine. Propranolol shifted the concentration-response curve to the right, though in a noncompetitive manner. Prazosin and yohimbine (α-antagonists) did not modify the response to dopamine. Isoprenaline produced a concentration-dependent relaxant response to the KCl-induced contraction antagonized by propranolol, but not by prazosin, in a noncompetitive manner. In conclusion, dopamine exhibits a relaxant effect on the isolated rat colon, which is not mediated by specific dopamine receptors or α-adrenoceptors but it may be mediated by atypical β-adrenoceptors. Key words: dopamine, isolated rat colon, dopamine receptors.

Control of the Subthalamic Innervation of Substantia Nigra Pars Reticulata by D1 and D2 Dopamine Receptors

2006 ◽  
Vol 95 (3) ◽  
pp. 1800-1811 ◽  
Author(s):  
Osvaldo Ibañez-Sandoval ◽  
Adán Hernández ◽  
Benjamin Florán ◽  
Elvira Galarraga ◽  
Dagoberto Tapia ◽  
...  
Keyword(s):  
Dopamine Receptors ◽  
Receptor Agonist ◽  
Sch 23390 ◽  
Receptor Activation ◽  
Skf 38393 ◽  
Projection Neurons ◽  
Patch Clamp Technique ◽  
D2 Dopamine Receptors ◽  
Endogenous Dopamine ◽  
Whole Cell Patch Clamp

The effects of activating dopaminergic D1 and D2 class receptors of the subthalamic projections that innervate the pars reticulata of the subtantia nigra (SNr) were explored in slices of the rat brain using the whole cell patch-clamp technique. Excitatory postsynaptic currents (EPSCs) that could be blocked by 6-cyano-7-nitroquinoxalene-2,3-dione and d-(−)-2-amino-5-phosphonopentanoic acid were evoked onto reticulata GABAergic projection neurons by local field stimulation inside the subthalamic nucleus in the presence of bicuculline. Bath application of ( RS)-2,3,4,5-tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine hydrochloride (SKF-38393), a dopaminergic D1-class receptor agonist, increased evoked EPSCs by ∼30% whereas the D2-class receptor agonist, trans-(−)-4aR-4,4a,5,6,7,8,8a,9-octahydro-5-propyl-1H-pyrazolo(3,4-g)quinoline (quinpirole), reduced EPSCs by ∼25%. These apparently opposing actions were blocked by the specific D1- and D2-class receptor antagonists: R-(+)-7-chloro-8-hydroxy-3-methyl-1-phenyl-2,3,4,5-tetra-hydro-1H-3-benzazepinehydrochloride (SCH 23390) and S-(−)-5-anino-sulfonyl- N-[(1-ethyl-2-pyrrolidinyl)-methyl]-2-methoxybenzamide (sulpiride), respectively. Both effects were accompanied by changes in the paired-pulse ratio, indicative of a presynaptic site of action. The presynaptic location of dopamine receptors at the subthalamonigral projections was confirmed by mean-variance analysis. The effects of both SKF-38393 and quinpirole could be observed on terminals contacting the same postsynaptic neuron. Sulpiride and SCH 23390 enhanced and reduced the evoked EPSC, respectively, suggesting a constitutive receptor activation probably arising from endogenous dopamine. These data suggest that dopamine presynaptically modulates the subthalamic projection that targets GABAergic neurons of the SNr. Implications of this modulation for basal ganglia function are discussed.

Comprehensive Quantification of the Right Ventricle: Pediatric Reference Values from 0 to 18 Years

2016 ◽  
Vol 64 (S 02) ◽  
Author(s):  
J. Horst ◽  
A. Karabiyik ◽  
H. Körperich ◽  
M. Fischer ◽  
E. Klusmeier ◽  
...  
Keyword(s):  
Right Ventricle ◽  
Reference Values ◽  
The Right

Right Ventricle Mass Removal from Tricuspid Valve Apparatus: An Unusual Thromboembolic Complication of Severe Ketoacidosis

2016 ◽  
Vol 19 (2) ◽  
pp. 077
Author(s):  
Ireneusz Haponiuk ◽  
Maciej Chojnicki ◽  
Konrad Paczkowski ◽  
Wojciech Kosiak ◽  
Radosław Jaworski ◽  
...  
Keyword(s):  
Right Ventricle ◽  
Tricuspid Valve ◽  
Mild Hypothermia ◽  
Heart Function ◽  
Thromboembolic Complication ◽  
Surgical Removal ◽  
Unusual Complication ◽  
Type I ◽  
Definitive Therapy ◽  
The Right

The presence of a pathologic mass in the right ventricle (RV) may lead to hemodynamic consequences and to a life-threatening incident of pulmonary embolism. The diagnosis of an unstable thrombus in the right heart chamber usually necessitates intensive treatment to dissolve or remove the pathology. We present a report of an unusual complication of severe ketoacidosis: thrombus in the right ventricle, removed from the tricuspid valve (TV) apparatus. A four-year-old boy was diagnosed with diabetes mellitus (DM) type I de novo. During hospitalization, a 13.9 × 8.4 mm tumor in the RV was found in a routine cardiac ultrasound. The patient was referred for surgical removal of the floating lesion from the RV. The procedure was performed via midline sternotomy with extracorporeal circulation (ECC) and mild hypothermia. Control echocardiography showed complete tumor excision with normal atrioventricular valves and heart function. Surgical removal of the thrombus from the tricuspid valve apparatus was effective, safe, and a definitive therapy for thromboembolic complication of pediatric severe ketoacidosis.<br /><br />

Ligation of a Fistula between the Left Main Coronary Artery and Both the Pulmonary Artery and the Right Ventricle

2012 ◽  
Vol 15 (2) ◽  
pp. 119 ◽  
Author(s):  
I. Halil Algin ◽  
Aytekin Yesilay ◽  
N. Murat Akcar
Keyword(s):  
Cardiopulmonary Bypass ◽  
Coronary Artery ◽  
Pulmonary Artery ◽  
Right Ventricle ◽  
Left Main Coronary Artery ◽  
Coronary Artery Fistula ◽  
Left Main ◽  
Symptomatic Disease ◽  
Coronary Artery Fistulas ◽  
The Right

The frequency of coronary artery fistula among all coronary angiography patients is 0.1% to 0.2%; however, involvement of both the pulmonary artery and the right ventricle is a rare clinical entity. A 53-year-old man patient was admitted to our clinic with rarely occurring chest pain, palpitations, and dyspnea. A coronary angiogram showed a fistula between the left main coronary artery and both the pulmonary artery and the right ventricle. We performed a ligation of this fistula without cardiopulmonary bypass. Aorta and right ventricle sutures were made, and the proximal and distal portions of the fistula were obliterated with 5-0 Prolene sutures and previously prepared Teflon felt. The patient recovered and was discharged without any complications. The surgical indications for coronary artery fistulas are symptomatic disease, an aneurysmic coronary artery, signs of heart failure, and ischemia. The surgical options in such cases�depending on whether the fistula is complicated or not�are simple ligation or transarterial ligation under cardiopulmonary bypass.

Pulmonary Vascular Versus Right Ventricular Function Changes During Targeted Therapies of Pulmonary Hypertension – An Argument for Upfront Combination Therapy?

2012 ◽  
Vol 8 (3) ◽  
pp. 209
Author(s):  
Wouter Jacobs ◽  
Anton Vonk-Noordegraaf ◽  
◽  
Keyword(s):  
Combination Therapy ◽  
Right Ventricle ◽  
Right Ventricular ◽  
Pulmonary Vascular Resistance ◽  
Vascular Resistance ◽  
Meta Analysis ◽  
Right Heart Failure ◽  
Functional Class ◽  
Pulmonary Vasculature ◽  
The Right

Pulmonary arterial hypertension is a progressive disease of the pulmonary vasculature, ultimately leading to right heart failure and death. Current treatment is aimed at targeting three different pathways: the prostacyclin, endothelin and nitric oxide pathways. These therapies improve functional class, increase exercise capacity and improve haemodynamics. In addition, data from a meta-analysis provide compelling evidence of improved survival. Despite these treatments, the outcome is still grim and the cause of death is inevitable – right ventricular failure. One explanation for this paradox of haemodynamic benefit and still worse outcome is that the right ventricle does not benefit from a modest reduction in pulmonary vascular resistance. This article describes the physiological concepts that might underlie this paradox. Based on these concepts, we argue that not only a significant reduction in pulmonary vascular resistance, but also a significant reduction in pulmonary artery pressure is required to save the right ventricle. Haemodynamic data from clinical trials hold the promise that these haemodynamic requirements might be met if upfront combination therapy is used.

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