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Development of diagnostic criteria and severity scale for polydipsia: A systematic literature review and well-experienced clinicians' consensus. Psychiatry Res 2021; 297:113708. [PMID: 33461119 DOI: 10.1016/j.psychres.2021.113708] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/04/2020] [Accepted: 12/31/2020] [Indexed: 11/21/2022]
Abstract
Despite the clinical importance of polydipsia, no diagnostic criteria or severity scales that comprehensively assess this condition are available. Thus, we aimed to develop diagnostic criteria and a severity scale for polydipsia based on a systematic review and well-experienced clinicians' consensus. We performed a systematic review, identified 27 studies related to diagnostic criteria or severity classification for polydipsia, and extracted items used to assess polydipsia in these studies. Ten well-experienced clinicians-5 psychiatrists and 5 nurses-participated in the Delphi method. They evaluated 39 items extracted based on the results of the systematic review regarding (1) their necessity in diagnosing and assessing the severity of polydipsia, and (2) their relative importance rated on 7-point scale among the items included in the severity scale. The Polydipsia Diagnostic Criteria (PDC) included 4 essential items-excessive drinking, low serum sodium level or low serum osmolality, abnormal normalized diurnal weight gain, and low urine specific gravity-based on consensus reached using the Delphi method. The Polydipsia Severity Scale (PSS) included 13 items with a maximum score of 59. The first diagnostic criteria and symptom scale for polydipsia were developed based on the findings of a systematic review and well-experienced clinicians' consensus.
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Petković B, Kesić S, Ristić S, Pavković Ž, Podgorac J, Stojadinović G, Pešić V. A New Look at an Old Drug: Cumulative Effects of Low Ribavirin Doses in Amphetamine-Sensitized Rats. Curr Pharm Des 2020; 26:3884-3894. [PMID: 32213154 PMCID: PMC8383471 DOI: 10.2174/1381612826666200326125821] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Accepted: 02/22/2020] [Indexed: 11/22/2022]
Abstract
Background Psychotic states related to psychostimulant misuse in patients with hepatitis C virus infection may complicate acceptance and reaction to antiviral treatment. This observation equally applies to the widely used ribavirin therapy. Objective We examined psychomotor and body weight gain responses to low ribavirin doses after cessation of intermittent amphetamine treatment in adult rats to assess its role in neurobehavioral outcome during psychostimulant withdrawal. Method The model of amphetamine-induced (1.5 mg/kg/day, i.p., 7 consecutive days) motor sensitization and affected body weight gain was established in adult male Wistar rats. Then, additional cohort of amphetamine-sensitized rats was subjected to saline (0.9% NaCl; 1 mL/kg/day; i.p.) or ribavirin (10, 20 and 30 mg/kg/day, i.p.) treatment for 7 consecutive days. Animals’ motor activity in a novel environment was monitored after the 1st and the 7th saline/ribavirin injection. Body weight gain was calculated as appropriate. Determination and quantification of ribavirin in the brain tissue were performed also. Results The 1st application of ribavirin to amphetamine-sensitized rats affected/decreased their novelty-induced motor activity only at a dose of 30 mg/kg. After the 7th application, ribavirin 30 mg/kg/day still decreased, while 10 and 20 mg/kg/day increased novelty-induced motor activity. These behavioral effects coincided with the time required to reach maximum ribavirin concentration in the brain. Body weight gain during withdrawal was not influenced by any of the doses tested. Conclusion Ribavirin displays central effects that in repeated treatment, depending on the applied dose, could significantly influence psychomotor response but not body weight gain during psychostimulant/amphetamine withdrawal.
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Affiliation(s)
- Branka Petković
- Department of Neurophysiology, Institute for Biological Research "Siniša Stanković" - National Institute of Republic of Serbia, University of Belgrade, Belgrade, Serbia
| | - Srđan Kesić
- Department of Neurophysiology, Institute for Biological Research "Siniša Stanković" - National Institute of Republic of Serbia, University of Belgrade, Belgrade, Serbia
| | - Slavica Ristić
- Institute for Research and Development, Galenika a.d., Belgrade, Serbia
| | - Željko Pavković
- Department of Neurobiology, Institute for Biological Research "Sinisa Stankovic" - National Institute of Republic of Serbia, University of Belgrade, Belgrade, Serbia
| | - Jelena Podgorac
- Department of Neurophysiology, Institute for Biological Research "Siniša Stanković" - National Institute of Republic of Serbia, University of Belgrade, Belgrade, Serbia
| | - Gordana Stojadinović
- Department of Neurophysiology, Institute for Biological Research "Siniša Stanković" - National Institute of Republic of Serbia, University of Belgrade, Belgrade, Serbia
| | - Vesna Pešić
- Department of Neurobiology, Institute for Biological Research "Sinisa Stankovic" - National Institute of Republic of Serbia, University of Belgrade, Belgrade, Serbia
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Szechtman H, Ahmari SE, Beninger RJ, Eilam D, Harvey BH, Edemann-Callesen H, Winter C. Obsessive-compulsive disorder: Insights from animal models. Neurosci Biobehav Rev 2017; 76:254-279. [PMID: 27168347 PMCID: PMC5833926 DOI: 10.1016/j.neubiorev.2016.04.019] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Revised: 04/22/2016] [Accepted: 04/26/2016] [Indexed: 01/15/2023]
Abstract
Research with animal models of obsessive-compulsive disorder (OCD) shows the following: (1) Optogenetic studies in mice provide evidence for a plausible cause-effect relation between increased activity in cortico-basal ganglia-thalamo-cortical (CBGTC) circuits and OCD by demonstrating the induction of compulsive behavior with the experimental manipulation of the CBGTC circuit. (2) Parallel use of several animal models is a fruitful paradigm to examine the mechanisms of treatment effects of deep brain stimulation in distinct OCD endophenotypes. (3) Features of spontaneous behavior in deer mice constitute a rich platform to investigate the neurobiology of OCD, social ramifications of a compulsive phenotype, and test novel drugs. (4) Studies in animal models for psychiatric disorders comorbid with OCD suggest comorbidity may involve shared neural circuits controlling expression of compulsive behavior. (5) Analysis of compulsive behavior into its constitutive components provides evidence from an animal model for a motivational perspective on OCD. (6) Methods of behavioral analysis in an animal model translate to dissection of compulsive rituals in OCD patients, leading to diagnostic tests.
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Affiliation(s)
- Henry Szechtman
- Department of Psychiatry and Behavioural Neurosciences, McMaster University, Hamilton, ON, Canada.
| | - Susanne E Ahmari
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA.
| | - Richard J Beninger
- Departments of Psychology and Psychiatry, Queen's University, Kingston, ON, Canada.
| | - David Eilam
- Department of Zoology, Tel-Aviv University, Ramat-Aviv 69978, Israel.
| | - Brian H Harvey
- MRC Unit on Anxiety and Stress Disorders, Center of Excellence for Pharmaceutical Sciences, School of Pharmacy, North-West University, Potchefstroom, South Africa.
| | - Henriette Edemann-Callesen
- Bereich Experimentelle Psychiatrie, Klinik und Poliklinik für Psychiatrie und Psychotherapie, Universitätsklinikum Carl Gustav Carus an der Technischen Universität Dresden, Dresden, Germany.
| | - Christine Winter
- Bereich Experimentelle Psychiatrie, Klinik und Poliklinik für Psychiatrie und Psychotherapie, Universitätsklinikum Carl Gustav Carus an der Technischen Universität Dresden, Dresden, Germany.
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Differences in the structure of drinking, cart expression and dopamine turnover between polydipsic and non polydipsic rats in the quinpirole model of psychotic polydipsia. Psychopharmacology (Berl) 2014; 231:3889-97. [PMID: 24647922 DOI: 10.1007/s00213-014-3527-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Accepted: 02/26/2014] [Indexed: 12/19/2022]
Abstract
RATIONALE Dopaminergic D2/D3 agonist quinpirole (QNP) elicits nonregulatory drinking in rats, a model of psychotic polydipsia. Why only a fraction of QNP-treated rats responds to the treatment becoming polydipsic is still unclear. OBJECTIVES To unveil possible factors contributing to such variability, we analyzed drinking microstructure in saline and QNP-treated rats, the hypothalamic expression of the cocaine and amphetamine regulated transcript (CART), and the monoaminergic turnover in selected brain areas. METHODS Rats were daily treated with saline or QNP 0.5 mg/kg, and their 5-h water intake was measured for five consecutive days. The number of bouts and episodes of licking, and their duration, were also measured. Brain CART expression was measured by in situ hybridization and monoamines turnover by HPLC analysis of tissue extracts. Based on the amount of water ingested during the 5-h session, QNP-treated rats were post hoc grouped in polydipsic (PD) and in nonpolydipsic (NPD) rats, and the results compared accordingly. RESULTS The number of drinking bouts and episodes increased in PD rats, while NPD rats behaved as the controls. CART expression decreased in the arcuate nucleus of the hypothalamus of the PD rats. In contrast, both PD and NPD rats showed a reduction of DA turnover in both ventral tegmental area (VTA) and nucleus accumbens (NAcc). No difference was detected in the turnover of 5HT and NA. CONCLUSIONS Microstructure analysis confirms that QNP acts on the appetitive component of drinking behavior, making it compulsive. CART expression reduction in response to dopaminergic hyperstimulation might sustain excessive drinking in PD rats.
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The amphetamine sensitization model of schizophrenia symptoms and its effect on schedule-induced polydipsia in the rat. Psychopharmacology (Berl) 2014; 231:2001-8. [PMID: 24241687 DOI: 10.1007/s00213-013-3345-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Accepted: 10/18/2013] [Indexed: 10/26/2022]
Abstract
RATIONALE Amphetamine enhances dopamine (DA) transmission and induces psychotic states or exacerbates psychosis in at-risk individuals. Amphetamine sensitization of the DA system has been proposed as a rodent model of schizophrenia-like symptoms. In humans, excessive nonphysiologic drinking or primary polydipsia is significantly associated with a diagnosis of schizophrenia. In rodents, nonphysiologic drinking can be induced by intermittent presentation of food in the presence of a drinking spout to a hungry animal; this phenomenon is termed, "schedule-induced polydipsia" (SIP). OBJECTIVE This study aims to determine the effects of amphetamine sensitization on SIP. METHODS We injected rats with amphetamine (1.5 mg/kg) daily for 5 days. Following 4 weeks of withdrawal, animals were food restricted and exposed to the SIP protocol (noncontingent fixed-time 1-min food schedule) for daily 2-h sessions for 24 days. RESULTS Results showed that previously amphetamine-injected animals drank more in the SIP protocol and drank more than controls when the intermittent food presentation schedule was removed. CONCLUSIONS These findings suggest that hyperdopaminergia associated with schizophrenia may contribute to the development of polydipsia in this population. Whether animals that develop SIP have DA dysfunction or aberrant activity of other circuits that modulate DA activity has yet to be clearly defined.
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Effects of the 5HT2C antagonist SB242084 on the pramipexole-induced potentiation of water contrafreeloading, a putative animal model of compulsive behavior. Psychopharmacology (Berl) 2013; 227:55-66. [PMID: 23241649 DOI: 10.1007/s00213-012-2938-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2012] [Accepted: 11/26/2012] [Indexed: 01/07/2023]
Abstract
RATIONALE In rats, quinpirole, a dopaminergic D2/D3 receptor agonist, elicits both hyperdipsia and water "contrafreeloading" (CFL), a putative model of compulsivity. The role of D3 receptors in this effect remains unclear. Clomipramine (CIM) was found to contrast both hyperdipsia and CFL, but the role of serotonin in this effect requires further investigation. OBJECTIVES We studied the effects of the preferential D3 agonist pramipexole (PPX) in both models. Furthermore, we tested the sensitivity of PPX-induced CFL to CIM and to the 5HT2c antagonist SB242084. METHODS In experiment 1, drinking was measured at 2 and 5 h after eight daily injections of PPX (0 to 1.0 mg/kg intraperitoneally). In the CFL study, every other third lever press, the rat was reinforced by the delivery of water. On days 1-6, water was only available upon lever pressing. On days 7-15, choice between response-contingent and free access was provided. PPX doses as in the experiment 1 were given. In two further experiments, PPX (0.5 mg/kg) was administered alone or in combination with CIM (5 or 10 mg/kg) or SB242084 (0.3 or 1.0 mg/kg). RESULTS PPX did not produce hyperdipsia but enhanced spontaneous CFL. SB242084 attenuated PPX-induced CFL more effectively than CIM, restoring the preference for free access to water. CONCLUSIONS CFL, but not polydipsia, was induced by preferential D3 activation, an effect prevented by 5HT2c receptor blockade. Since PPX interferes with decision making and 5HT2c receptor supersensitivity is involved in the expression of compulsive behaviors, this study supports the compulsive nature of dopaminergic-induced CFL.
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Amato D, Müller CP, Badiani A. Increased drinking after intra-striatal injection of the dopamine D2/D3 receptor agonist quinpirole in the rat. Psychopharmacology (Berl) 2012; 223:457-63. [PMID: 22581392 DOI: 10.1007/s00213-012-2735-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2012] [Accepted: 04/24/2012] [Indexed: 11/29/2022]
Abstract
RATIONALE Dopamine D2 receptor hyperactivity has been implicated in the development of psychogenic polydipsia in schizophrenic patients. Repeated treatment with dopamine agonists, including the D2/D3 agonist quinpirole, has been shown to induce hyperdipsia in a number of animal models. Despite these observations, obtained with systemic administrations, little attempt has been made to investigate where in the brain dopamine agonists act to induce hyperdipsia. OBJECTIVE The present study investigates the effects of repeated intra-caudate infusions of quinpirole on the intake of water by rats tested under free-drinking conditions. MATERIALS AND METHODS Rats with bilateral cannulae placed into the anterior, central or posterior caudate received quinpirole microinfusions (1 μg/side) for five consecutive days in their home cage. Water intake was measured 15 and 60 min after the treatment. RESULTS When injected in the central caudate, quinpirole increased water intake, and this effect progressively increased over sessions, indicating the development of sensitization. When injected in the posterior caudate, the dipsogenic effect of quinpirole was less intense and did not undergo sensitization. The infusion of quinpirole in the anterior caudate did not affect drinking. CONCLUSION The present study shows that caudate D2/3 receptors play an important role in the development of quinpirole-induced hyperdipsia, an animal model of psychotic polydipsia.
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Affiliation(s)
- Davide Amato
- Section of Addiction Medicine, Department of Psychiatry and Psychotherapy, Friedrich-Alexander-University Erlangen-Nuremberg, 91054 Erlangen, Germany.
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Pellón R, Ruíz A, Moreno M, Claro F, Ambrosio E, Flores P. Individual differences in schedule-induced polydipsia: Neuroanatomical dopamine divergences. Behav Brain Res 2011; 217:195-201. [DOI: 10.1016/j.bbr.2010.10.010] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2009] [Revised: 10/08/2010] [Accepted: 10/12/2010] [Indexed: 10/18/2022]
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The effects of clozapine on quinpirole-induced non-regulatory drinking and prepulse inhibition disruption in rats. Psychopharmacology (Berl) 2010; 212:105-15. [PMID: 20623106 DOI: 10.1007/s00213-010-1937-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2010] [Accepted: 06/23/2010] [Indexed: 01/11/2023]
Abstract
RATIONALE The biological underpinnings of schizophrenic polydipsia are poorly understood. OBJECTIVES This study is aimed at fulfilling the requisites of an experimental model of this syndrome through the quinpirole (QNP) induction of non-regulatory drinking in rats. METHODS In a first experiment, clozapine (10 and 40 mg/kg p.o.) was substituted for haloperidol during the last 5 days of 10 days QNP (0.5 mg/kg i.p.) administration and water intake measured at 5 h. In a second experiment, animals treated with QNP alone or in combination with clozapine were assessed for water intake and prepulse inhibition (PPI). Expression of genes coding for the dopaminergic D2 receptor, as well as for the early genes BDNF (brain-derived neurotrophic factor) and c-Fos in prefrontal cortex, hippocampus, and striatum was also evaluated. RESULTS Clozapine prevented QNP-induced drinking at 10 and 40 mg/kg, but only at 40 mg/kg when it was substituted for haloperidol. In the second experiment, QNP-treated rats showed both non-regulatory drinking and PPI disruption. Both these effects were prevented by clozapine 40 mg/kg. QNP-reduced BDNF expression in the hippocampus and increased c-Fos in the prefrontal cortex. This effect was prevented by clozapine. Given by itself, clozapine reduced the expression of both D2 receptors and BDNF in the prefrontal cortex and striatum. CONCLUSIONS The present study lends further support to the hypothesis that non-regulatory drinking induced by QNP in rats is a robust and reliable pharmacological effect that might model psychotic polydipsia also in its sensitivity to clozapine.
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Milella MS, Passarelli F, De Carolis L, Schepisi C, Nativio P, Scaccianoce S, Nencini P. Opposite roles of dopamine and orexin in quinpirole-induced excessive drinking: a rat model of psychotic polydipsia. Psychopharmacology (Berl) 2010; 211:355-66. [PMID: 20552172 DOI: 10.1007/s00213-010-1909-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2010] [Accepted: 06/03/2010] [Indexed: 02/05/2023]
Abstract
RATIONALE Repeated administration of the dopamine D2/D3 agonist quinpirole (QNP) progressively increases non-regulatory water intake. This effect may model psychotic polydipsia, a potentially fatal but poorly understood condition. OBJECTIVES The growing evidence for a role of orexin in mediating arousal and cognition has linked this peptide to schizophrenia, hence we examined whether manipulations of dopaminergic and orexinergic systems, as well as of setting, would further characterize the model. METHODS Water intake was measured in rats sequentially tested in home and then operant conditioning setting, with chronic administration of D2 antagonist haloperidol (Hal) prior to QNP treatment. A group of rats similarly treated was also assessed for orexin A (OxA) expression in the cortex. Finally, the effect of the orexin-1 receptor antagonist SB-334867 on QNP-induced polydipsia was evaluated. RESULTS In rats made polydipsic by QNP the amount of water drank during the first 4 h was strongly correlated with the degree of dissociation between appetitive and consummatory components of drinking behavior in the following hour of operant access to water. Hal 0.2 mg/kg prevented both polydipsia and the dissociation, while 0.1 mg/kg only blocked the dissociation. Chronic QNP treatment increased, in a Hal-reversible way, OxA expression in the somatosensory cortex (SI). Moreover, pretreatment with SB-334867 sped up and potentiated QNP-induced polydipsia. CONCLUSIONS Results disclose compulsive components in QNP-induced polydipsia that are mediated by dopamine D2 receptors. QNP also regulates OxA expression in the SI, while the block of orexin-1 receptors enhances QNP-induced polydipsia. We suggest that dopamine and OxA play opposite roles in QNP-induced polydipsia.
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Affiliation(s)
- Michele S Milella
- Department of Physiology and Pharmacology "Vittorio Erspamer", Sapienza University of Rome, 5 Piazzale Aldo Moro, 00185 Rome, Italy
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Caykoylu A, Ekinci O, Albayrak Y. Successful quetiapine treatment in a schizophrenic patient with polydipsia and dyskinesia: a case report. Prog Neuropsychopharmacol Biol Psychiatry 2009; 33:1557-8. [PMID: 19733605 DOI: 10.1016/j.pnpbp.2009.08.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2009] [Revised: 08/25/2009] [Accepted: 08/26/2009] [Indexed: 10/20/2022]
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Amato D, Stasi MA, Borsini F, Nencini P. Haloperidol both prevents and reverses quinpirole-induced nonregulatory water intake, a putative animal model of psychogenic polydipsia. Psychopharmacology (Berl) 2008; 200:157-65. [PMID: 18597076 DOI: 10.1007/s00213-008-1229-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2008] [Accepted: 06/03/2008] [Indexed: 10/21/2022]
Abstract
RATIONALE Polydipsia is a severe complication of long-term schizophrenia and, despite its unknown pathogenesis, is empirically treated with typical or atypical antipsychotics. In the rat, nonregulatory water intake is induced by repeated administration of amphetamine-like compounds or by the D2/3 agonist, quinpirole. OBJECTIVE This study is aimed at determining the potential activity of antipsychotic compounds with different affinities for D2 receptors in preventing and/or reversing quinpirole-induced polydipsia. MATERIALS AND METHODS Male Sprague-Dawley rats were treated with five injections of quinpirole (0.5 mg/kg i.p.) to induce polydipsia. The oral effects of haloperidol, olanzapine, clozapine, and ST2472 on QNP-induced polydipsia were analyzed in the following two schedules. In the preventive schedule, haloperidol (0.2, 0.4, and 0.8 mg/kg), olanzapine (1.5, 3, and 6 mg/kg), ST2472 (1 and 2 mg/kg), and clomipramine (5, 10, and 20 mg/kg) were given in combination with quinpirole from day 1 to day 5. In the reversal schedule, rats showing quinpirole-induced polydipsia on the third day received haloperidol (0.4 mg/kg), olanzapine (1.5 and 3 mg/kg), clozapine (10, 20, and 40 mg/kg), ST2472 (1, 2, 5, and 10 mg/kg), and clomipramine (5, 10, and 20 mg/kg) before quinpirole on days 4 and 5. RESULTS Haloperidol both prevented and reversed quinpirole-induced polydipsia, whereas olanzapine and ST2472 only reversed it. Clomipramine prevented but did not reverse quinpirole-induced polydipsia, and clozapine did not reverse it either. CONCLUSIONS We suggest that, once developed, polydipsia is governed by dopaminergic D2 mechanisms. In contrast, either an increase in the serotoninergic tone or an inhibition of D2 receptors can modulate the development of quinpirole-induced excessive drinking.
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Affiliation(s)
- Davide Amato
- Department of Human Physiology and Pharmacology "Vittorio Erspamer", University of Rome "La Sapienza", Piazzale Aldo Moro 5, 00185, Rome, Italy
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Milella MS, Amato D, Badiani A, Nencini P. The influence of cost manipulation on water contrafreeloading induced by repeated exposure to quinpirole in the rat. Psychopharmacology (Berl) 2008; 197:379-90. [PMID: 18189126 DOI: 10.1007/s00213-007-1044-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2007] [Accepted: 12/04/2007] [Indexed: 01/04/2023]
Abstract
RATIONALE Quinpirole (QNP), a D2/D3 dopaminergic receptor agonist, was found to elicit an apparently antieconomical drinking behavior called contrafreeloading (CFL). The perseverative operant responding observed may represent a compulsive-like behavior prompted by sensitization to the effects of QNP. OBJECTIVES In the present study, we investigated the effect of different response costs on instrumental behavior and CFL in rats repeatedly treated with QNP (0.5 mg/kg i.p.). Moreover, we studied the consummatory components of ingestive behavior in no-choice paradigms and the role of learned operant conditioning in free drinking. MATERIALS AND METHODS In experiment 1, rats were trained to perform under three different fixed ratio schedules of reinforcement (FR1, FR3, and FR10) and were given a choice between operant and free access to water. In experiment 2, rats were divided into four groups, each one resembling experiment 1 in one or more features, with no choice available and water consumption measured at an interval of 0-60 min. RESULTS (a) Increasing FR significantly reduced CFL % in saline -- but not in QNP-injected groups; (b) under free-drinking conditions, QNP caused a progressive hypodipsic effect which was, however, contrasted by maintaining cues formerly contingent on operant access to water; and (c) under CFL conditions QNP-treated rats drank more than under free access conditions. CONCLUSIONS QNP confers rigidity in responding for water, impeding adaptation to different contingencies for access to the resource. In QNP-treated rats, CFL behavior appears adaptive as far as it allows animals to partially circumvent the hypodipsic effect of the drug.
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Affiliation(s)
- Michele S Milella
- Department of Human Physiology and Pharmacology Vittorio Erspamer, University of Rome Sapienza, Rome, Italy
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Abstract
Khat chewing is deeply rooted in the every day life of people living in the Horn of Africa and in South Arabia, where Catha edulis is endemic. Considered little more than an exotic habit producing just mild pharmacological effects, systematic investigations on its active principles have instead lead to the isolation and chemical characterization of cathinone, a compound structurally related to amphetamine. Three decades of intense experimental and clinical research on khat have depicted a consistently clear picture of its pharmacological and toxicological effects.
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Affiliation(s)
- Manuela Graziani
- Department of Human Physiology and Pharmacology, University of Rome, La Sapienza, Rome, Italy
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Collins GT, Woods JH. Drug and reinforcement history as determinants of the response-maintaining effects of quinpirole in the rat. J Pharmacol Exp Ther 2007; 323:599-605. [PMID: 17675585 DOI: 10.1124/jpet.107.123042] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The present study examined the effect of drug and reinforcement history on quinpirole-maintained responding in rats. Quinpirole (0.01, 0.032, or 0.1 mg/kg per injection) was assessed as a reinforcer in experimentally naive rats, as well as in rats trained to self-administer cocaine, remifentanil, ketamine, or food under a fixed ratio 1 schedule of reinforcement. Quinpirole failed to maintain responding in experimentally naive rats, or in ketamine- or food-trained rats. However, robust responding was maintained in rats with a history of cocaine reinforcement, and modest levels of responding were observed in rats with a history of responding for remifentanil. In a second set of studies, the effects of protracted drug histories on quinpirole-maintained responding in food-trained rats were assessed. Rats were maintained with food reinforcement, and different groups of rats were then allowed to respond for saline, quinpirole, and response-contingent cocaine or were administered noncontingent cocaine; all rats were subsequently allowed to respond for quinpirole. Only rats that previously responded for cocaine showed quinpirole-maintained responding; all other conditions failed to establish quinpirole-maintained responding. Although the high levels of quinpirole-maintained responding observed when quinpirole was substituted for cocaine are suggestive of positive reinforcing effects, these response-maintaining effects were highly dependent upon both drug and reinforcement history, suggesting that quinpirole may only function as a reinforcer under very specific conditions. The behavioral effects of quinpirole under these situations represent a novel constellation of actions relative to other drug reinforcers, and they suggest that the direct effects of self-administered quinpirole may be important in establishing the response-maintaining effects.
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Affiliation(s)
- Gregory T Collins
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, Michigan 48109-0632, USA
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Bersani G, Pesaresi L, Orlandi V, Gherardelli S, Pancheri P. Atypical antipsychotics and polydipsia: a cause or a treatment? Hum Psychopharmacol 2007; 22:103-7. [PMID: 17335101 DOI: 10.1002/hup.825] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Primary polydipsia (PP) is a frequent complication that affects many chronic schizophrenic inpatients. Due to possible lethal consequences, for example, hyponatremia, coma and death, it's fundamental for the physician achieving early diagnosis and treating this condition. The first step is identifying polydipsia by clinical, biochemical and pharmacological means. Nowadays, the pathophysiology of PP remains unclear, and this limits the possibility of detecting an appropriate drug treatment. Typical antipsychotics have been associated to a worsening of polydipsic behavior, while more recently atypical antipsychotics have been reported as being useful. However results are still mixed and controversial. It appears that risperidone and olanzapine are not clearly effective; clozapine may improve symptoms, although it is difficult to manage from a therapeutic point of view; quetiapine has been poorly studied so far, nonetheless it has given interesting results. Through a case study analysis, this report presents a brief, yet selective, overview of the current state of psychopharmacology in the treatment of PP with atypical antipsychotics in schizophrenia.
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Affiliation(s)
- Giuseppe Bersani
- University of Rome, La Sapienza, III Psychiatric Clinic, Department of Psychiatric Sciences and Psychological Medicine, Italy.
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17
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Amato D, Milella MS, Badiani A, Nencini P. Compulsive-like effects of repeated administration of quinpirole on drinking behavior in rats. Behav Brain Res 2006; 172:1-13. [PMID: 16677719 DOI: 10.1016/j.bbr.2006.03.038] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2006] [Revised: 03/29/2006] [Accepted: 03/30/2006] [Indexed: 10/24/2022]
Abstract
We have previously reported that repeated administrations of quinpirole, a D2/D3 dopamine receptor agonist, facilitate instrumental behavior in rats given the choice between operant and free access to water (contrafreeloading: CFL). The goal of the present study was to investigate the effects of repeated daily administrations of quinpirole (0.5 mg/kg i.p.) on the appetitive versus the consummatory component of water-reinforced behavior, under two experimental conditions. Under one condition, the rats were given access to tap water according to an FR3 schedule of reinforcement. Under the second condition, the rats were given the choice between operant and free access to water. Five major findings were obtained. First, acutely quinpirole suppressed operant behavior and, therefore, water intake for at least 1h. Second, upon repeated administrations tolerance developed to the suppressant effect of quinpirole on instrumental behavior but only to a lesser extent to the antidipsic effect, dissociating the appetitive from the consummatory components of water-reinforced behavior. Third, in CFL conditions quinpirole induced a progressively larger preference for the operant access. Fourth, even when the rats were given the choice between free access to highly palatable saccharine (0.05 or 0.01%) solutions and operant access to tap water, quinpirole shifted the animals towards the operant access. Fifth, repeated quinpirole produced lasting consequences on drinking behavior, since after rehydration and under drug-free conditions quinpirole-pretreated rats ingested larger amounts of water than control rats. In conclusion, the repeated activation of D2/D3 receptors appears to induce the rats to perseverate in performing needless instrumental behavior.
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Affiliation(s)
- Davide Amato
- Department of Human Physiology and Pharmacology "Vittorio Erspamer", University of Rome "La Sapienza", Piazzale Aldo Moro 5, I-00185 Rome, Italy
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Kuo DY. Involvement of hypothalamic neuropeptide Y in regulating the amphetamine-induced appetite suppression in streptozotocin diabetic rats. ACTA ACUST UNITED AC 2005; 127:19-26. [PMID: 15680466 DOI: 10.1016/j.regpep.2004.10.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2004] [Revised: 10/18/2004] [Accepted: 10/21/2004] [Indexed: 11/27/2022]
Abstract
BACKGROUND AND AIM Amphetamine (AMPH) is a well-known anorectic agent. In normal rats, AMPH-induced anorexia has been attributed to its inhibitory action on hypothalamic neuropeptide Y (NPY), an appetite stimulant in the brain. In diabetic rats, however, if this anorectic response of AMPH might still be observed was uncertain. METHODS Rats (including normal, diabetic and insulin-treated diabetic rats) were given daily with saline or AMPH for 6 days. Changes in food intake, plasma glucose level (PGL) and NPY content of these rats were measured and compared. RESULTS The AMPH-induced anorectic response was altered in diabetic rats. Although the anorectic effects of AMPH on the first day of dosing were similar between diabetic and control rats, diabetic rats developed tolerance to this anorexia more rapidly than control rats. This alteration was independent of PGL since PGL levels were not changed following AMPH treatment and PGL normalization induced by phlorizin could not restore the level of AMPH anorexia. On the other hand, this alteration was dependent on the action of NPY because NPY contents were decreased following AMPH treatment and the replacement of insulin in diabetic rats could restore both NPY content and AMPH anorexia. CONCLUSION These results suggested that the elevated hypothalamic NPY content in diabetic rats was involved in modifying the anorectic response of AMPH.
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Affiliation(s)
- Dong-Yih Kuo
- Department of Physiology, Chung Shan Medical University, Taichung 40201, Taiwan, ROC.
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Hsieh YS, Yang SF, Kuo DY. Amphetamine, an appetite suppressant, decreases neuropeptide Y immunoreactivity in rat hypothalamic paraventriculum. ACTA ACUST UNITED AC 2005; 127:169-76. [PMID: 15680483 DOI: 10.1016/j.regpep.2004.11.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2004] [Revised: 11/10/2004] [Accepted: 11/18/2004] [Indexed: 11/17/2022]
Abstract
Amphetamine (AMPH) is a well-known anorectic agent. The mechanism underlying the anorectic response of AMPH has been attributed to its inhibitory effect on hypothalamic neuropeptide Y (NPY), an orexigenic peptide in the brain. However, there is still lack of genomic or in situ immunohistochemical evidence to prove it. The present study was aimed to assess the molecular mechanism of AMPH anorexia by immunostaining of hypothalamic NPY protein in the area of paraventricular nucleus (PVN) and by detecting the change of hypothalamic NPY mRNA level using RT-PCR. Results revealed that an AMPH treatment might reduce the expression of NPY at both transcriptional and posttranslational levels. Comparatively, a treatment of clomipramine, a serotonin transporter inhibitor, was unable to reduce NPY mRNA level, revealing the noninvolvement of hypothalamic NPY gene in serotonin anorexia. Our results provided genomic and in situ immunohistochemical evidence to confirm the mediation of hypothalamic NPY neurons in the anorectic action of AMPH.
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Affiliation(s)
- Yih-Shou Hsieh
- Institute of Biochemistry, Chung Shan Medical University, Taichung 40201, Taiwan
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Kuo DY. Further evidence for the mediation of both subtypes of dopamine D1/D2 receptors and cerebral neuropeptide Y (NPY) in amphetamine-induced appetite suppression. Behav Brain Res 2004; 147:149-55. [PMID: 14659580 DOI: 10.1016/j.bbr.2003.04.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Amphetamine (AMPH) is known as an anorectic agent. Repeated treatments of AMPH for several days induced a marked anorexia on day 1 followed by a gradual return of food intake to normal level. Previously, using daily food intake (DFI) as an indicator, we found that both dopamine (DA) D1 and D2 receptors were involved in AMPH anorexia. In the present study, using DFI and body weight change (BWC) as indicators, we took a further step to examine whether repeated co-administrations of D1 and D2 agonists might produce an AMPH-like action. Results revealed that repeated co-administrations of D1 and D2 agonists, but not D1 or D2 agonist alone, produced an AMPH-like action (i.e., tolerant DFI and BWC), confirming the previous study. In addition, we examined whether cerebral neuropeptide Y (NPY), an orexigenic neurotransmitter reported to mediate AMPH anorexia, was involved in the anorectic action of D1/D2 co-administration. Our result revealed that injection of NPY antisense into brain could modify the anorectic action of repeated D1/D2 agonists, indicating the involvement of NPY. Taken together, the present results confirmed that both subtypes of D1 and D2 receptors and cerebral NPY were involved in the anorectic action of AMPH.
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Affiliation(s)
- Dong-Yih Kuo
- Department of Physiology, Chung Shan Medical University, Taichung City, Taiwan 402, ROC.
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Kuo DY, Cheng JT. Role of cerebral dopamine but not plasma insulin, leptin and glucocorticoid in the development of tolerance to the anorectic effect of amphetamine. Neurosci Res 2002; 44:63-9. [PMID: 12204294 DOI: 10.1016/s0168-0102(02)00086-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Repeated treatment with amphetamine (AMPH), an anorectic agent, induced a marked anorexia on day 1 followed by a gradual reversion of this anorexia to the normal level of feeding (tolerant anorexia). The mechanism for this tolerant anorexia remained unknown because it might be related with multiple parameters, such as the change of cerebral dopamine (DA) or the plasma levels of insulin, leptin and glucocorticoid. Results revealed that plasma insulin and leptin concentrations remained unchanged during repeated AMPH administration, revealing that these two factors are not involved. Also, glucocorticoids were not required for the development of tolerant anorexia, as this effect could not be prevented by adrenalectomy. However, AMPH-induced anorexia was decreased by the pretreatment of alpha-methyl-p-tyrosine, an inhibitor of central catecholamine synthesis, and was increased by the pretreatment of nomifensine, a blocker of DA transporter that increased extracellular DA content in brain, revealing that the change of DA content could modify the action of tolerant anorexia. It is suggested that the decrease of inhibitory action of DA in brain during repeated AMPH plays a functional role in the development of tolerance to the anorectic response of AMPH.
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Affiliation(s)
- Dong-Yih Kuo
- Department of Physiology, Chung Shan Medical University, Taichung City 402, Taiwan, ROC
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Badiani A, Vaccaro R, Burdino R, Casini A, Valeri P, Renda TG, Nencini P. Dissociation in the effects of the D2/D3 dopaminergic agonist quinpirole on drinking and on vasopressin levels in the rat. Neurosci Lett 2002; 325:79-82. [PMID: 12044626 DOI: 10.1016/s0304-3940(02)00261-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In the present study, we investigated the role of vasopressin in the development of quinpirole-induced hyperdipsia in the rat. We report that: (1), an acute intraperitoneal (i.p.) injection of 0.56 mg/kg of quinpirole increased plasma vasopressin (radioimmunoassay) at 15 min but not at 30 or 120 min; (2), nine daily injections of quinpirole (0.56 mg/kg, i.p.) progressively increased water intake and diuresis for a period of several hours after each treatment; (3), quinpirole hyperdipsia was associated with apparently normal levels of vasopressin (which might be considered inappropriately high in the presence of excessive drinking); (4), quinpirole reduced vasopressin and oxytocin, but not angiotensin, immunoreactivity in the supraoptic nucleus. These findings suggest that quinpirole hyperdipsia is a sound animal model of psychotic polydipsia.
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Affiliation(s)
- Aldo Badiani
- Department of Human Physiology and Pharmacology, University of Rome La Sapienza, 5 Piazzale Aldo Moro, 00185 Rome, Italy.
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Savelieva KV, Caudle WM, Findlay GS, Caron MG, Miller GW. Decreased Ethanol Preference and Consumption in Dopamine Transporter Female Knock-Out Mice. Alcohol Clin Exp Res 2002. [DOI: 10.1111/j.1530-0277.2002.tb02602.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Chen TY, Duh SL, Huang CC, Lin TB, Kuo DY. Evidence for the involvement of dopamine D(1) and D(2) receptors in mediating the decrease of food intake during repeated treatment with amphetamine. J Biomed Sci 2001; 8:462-6. [PMID: 11702009 DOI: 10.1007/bf02256608] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Repeated treatment with amphetamine (AMPH), a well-known anorectic agent, into animals could induce anorexia on day 1 and produce a gradual reversion of food intake (tolerant anorexia) on the following days. It is unknown whether these feeding changes are related to dopamine (DA) and/or noradrenergic neurotransmission. Thus, the present study investigated the subtype of receptor mediating AMPH-induced anorexia. Daily food intake was measured after various drugs were given. Pretreatment with haloperidol, an antagonist of DA receptors, may lead to inhibition of AMPH-induced anorexia. However, pretreatment with the alpha-adrenoceptor antagonist phentolamine, and the beta-adrenoceptor antagonist propranolol, failed to modify the action of AMPH, suggesting the involvement of DA receptors but not adrenoceptors in the action of AMPH-induced anorexia. Furthermore, pretreatment with SCH 23390 at a dose sufficient to block D(1) receptors or pimozide at a dose sufficient to inhibit D(2) receptors blocked AMPH-induced anorexia, indicating the involvement of D(1) and D(2) receptors. In a study of tolerant anorexia, repeated treatment with the D(1)/D(2) agonist apomorphine, but not the D(1) agonist SKF 38393 or D(2) agonist quinpirole, induced an AMPH-like tolerant feeding response, providing evidence for conjoint action of D(1) and D(2) receptors in the effect. The present results suggest that both D(1) and D(2) receptors are involved in anorexia and tolerant anorexia induced by chronic intermittent administration of AMPH.
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Affiliation(s)
- T Y Chen
- Department of Internal Medicine, Chung-Shan Medical and Dental College, Taichung, Taiwan, ROC
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25
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Biomedical vignette. J Biomed Sci 2001. [DOI: 10.1007/bf02256604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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Cioli I, Caricati A, Nencini P. Quinpirole- and amphetamine-induced hyperdipsia: influence of fluid palatability and behavioral cost. Behav Brain Res 2000; 109:9-18. [PMID: 10699653 DOI: 10.1016/s0166-4328(99)00155-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Daily administration of moderate doses of amphetamine or of the dopaminergic D2 agonist quinpirole is associated with the development of excessive, non-regulatory drinking. Here we compared the influence of manipulating fluid palatability and behavioral cost on the development of this drinking augmentation. Experiment 1 was based on the phenomenon of contrafreeloading (CFL): animals work for a resource even though the same resource is freely available. The effects of 15 daily injections of amphetamine (1.0 and 1.7 mg/kg i.p. ) or quinpirole (0.1 and 0.56 mg/kg i.p.) were evaluated in mildly water-deprived rats. For the first 6 days the rats obtained water by lever pressing (FR3) only; over the following 9 days water was also freely available (CFL). Initially, 0.56 mg/kg quinpirole reduced lever pressing for water. A complete recover of responding was then obtained, and was followed by a progressive increment in the amount water obtained by lever pressing during the CFL phase (from 10 to 50%). Amphetamine did not affect percent CFL, but at the highest dose (1.7 mg/kg) reduced total water intake during the last 3 days of treatment. In experiment 2 the rats had free access to two bottles, one of which contained tap water, and the other contained either an ethanol (6%) or a sucrose (5%) solution. After habituation to this regimen, the rats received 10 daily i.p. injections of vehicle, amphetamine (1.0 or 3 mg/kg), or quinpirole (0.1 or 0.56 mg/kg). Quinpirole 0.56 mg/kg enhanced daily fluid intake under both sucrose and ethanol conditions, but selectively reduced ethanol preference. The higher amphetamine dose reduced fluid intake and sucrose preference. In conclusion, chronic exposure to a dopaminergic D2 agonist, but not to amphetamine, produced an increment of drinking that was resistant to manipulation of either palatability or the behavioral cost of the fluid.
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Affiliation(s)
- I Cioli
- Institute of Medical Pharmacology, University of Rome 'La Sapienza', P. le A. Moro 5, 00185, Rome, Italy
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Oades RD, Daniels R. Subclinical polydipsia and polyuria in young patients with schizophrenia or obsessive-compulsive disorder vs normal controls. Prog Neuropsychopharmacol Biol Psychiatry 1999; 23:1329-44. [PMID: 10631761 DOI: 10.1016/s0278-5846(99)00069-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
1. Increased water intake and output is more common among psychiatric patients, especially those with schizophrenia, than in the general population. Animal studies suggest that polydipsia and polyuria derive, in part, from dopamine dysregulation. Stimulated by these observations this study sought to elucidate relationships among water homeostasis, monoamine metabolism, and electrolyte excretion in schizophrenic patients with and without paranoid hallucinatory symptoms (PH vs. NP), thought to reflect hyper- and hypo-dopaminergic states respectively, and to compare these with those shown by patients with obsessive compulsive disorder (OCD). 2. 24 hr-urine samples for electrolyte, monoamine and metabolite measures were taken from 14 schizophrenic patients with PH symptoms, 13 with predominantly nonparanoid (NP) symptoms, 11 OCD patients and 27 healthy controls (matched for age, weight and creatinine production). Water intake and serum electrolytes was sampled during psychological testing. 3. PH patients drank 2-3 times more than the others in a 3-4 hr test, yet 24 hr-urinary volumes were 75% larger in both PH and NP patients than in the two comparison groups. 4. Daily potassium excretion was a bit higher in PH patients, but concentrations of sodium, potassium and phosphate tended to be lower in PH and NP patients than in the others. 5. Positive associations of electrolyte with homovanillic acid excretion were consistent across groups and not directly related to medication. But associations of electrolyte excretion with noradrenergic activity in controls were absent in psychotic patients and associations with serotonin in OCD patients were absent in the other groups. 6. Increased water intake and output in PH patients along with the disturbed association with noradrenergic metabolism are consistent with altered autonomic activity in these patients. 7. The independence of measures of water homeostasis from dopaminergic medication indicates that the associations in clinically responding PH patients of polydipsia with DA function (decreased DA levels) may be pertinent to this subgroup but not to schizophrenia in general.
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Affiliation(s)
- R D Oades
- Biological Psychiatry Group, University Psychiatry Clinics, Essen, Germany.
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