Telemetry monitoring for non-invasive assessment of changes in core temperature after spinal drug administration in freely moving rats

Safrany-Fark, Arpad; Petrovszki, Zita; Kekesi, Gabriella; Keresztes, Csilla; Benedek, György; Horváth, Gyöngyi

doi:10.1016/j.vascn.2015.01.002

Cited by 7 publications

(6 citation statements)

References 34 publications

(44 reference statements)

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“…These rats presented moderate to severe imbalance and ataxia, and loss of body weight. Similar effects were described by Safrany-Fark and colleagues, who observed short-lasting hyperactivity after single dose of KYNA [ 22 ]. In another study, the intrathecal administration of KYNA as reported to cause a dose-dependent antinociception and long-lasting motor impairment [ 21 ].…”

Section: Discussionsupporting

confidence: 85%

“…An increase in brain KYNA level has led to significant neurochemical and morphological disorders affecting different cognitive dysfunctions [ 20 ]. An intrathecal KYNA administration has resulted in a motor dysfunction and antinociception [ 21 , 22 ]. Moreover, a continuous intrathecal infusion of KYNA at the doses 0.1–4 μg/min for 60 min has resulted in motor paralysis, and this effect was temporary and reversible [ 23 ].…”

Section: Introductionmentioning

confidence: 99%

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Prolonged Subdural Infusion of Kynurenic Acid Is Associated with Dose-Dependent Myelin Damage in the Rat Spinal Cord

et al. 2015

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BackgroundKynurenic acid (KYNA) is the end stage metabolite of tryptophan produced mainly by astrocytes in the central nervous system (CNS). It has neuroprotective activities but can be elevated in the neuropsychiatric disorders. Toxic effects of KYNA in the CNS are unknown. The aim of this study was to assess the effect of the subdural KYNA infusion on the spinal cord in adult rats.MethodsA total of 42 healthy adult rats were randomly assigned into six groups and were infused for 7 days with PBS (control) or 0.0002 pmol/min, 0.01 nmol/min, 0.1 nmol/min, 1 nmol/min, and 10 nmol/min of KYNA per 7 days. The effect of KYNA on spinal cord was determined using histological and electron microscopy examination. Myelin oligodendrocyte glycoprotein (MOG) was measured in the blood serum to assess a degree of myelin damage.ResultIn all rats continuous long-lasting subdural KYNA infusion was associated with myelin damage and myelin loss that was increasingly widespread in a dose-depended fashion in peripheral, sub-pial areas. Damage to myelin sheaths was uniquely related to the separation of lamellae at the intraperiod line. The damaged myelin sheaths and areas with complete loss of myelin were associated with limited loss of scattered axons while vast majority of axons in affected areas were morphologically intact. The myelin loss-causing effect of KYNA occurred with no necrosis of oligodendrocytes, with locally severe astrogliosis and no cellular inflammatory response. Additionally, subdural KYNA infusion increased blood MOG concentration. Moreover, the rats infused with the highest doses of KYNA (1 and 10 nmol/min) demonstrated adverse neurological signs including weakness and quadriplegia.ConclusionsWe suggest, that subdural infusion of high dose of KYNA can be used as an experimental tool for the study of mechanisms of myelin damage and regeneration. On the other hand, the administration of low, physiologically relevant doses of KYNA may help to discover the role of KYNA in control of physiological myelination process.

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Section: Discussionsupporting

confidence: 85%

Section: Introductionmentioning

confidence: 99%

Prolonged Subdural Infusion of Kynurenic Acid Is Associated with Dose-Dependent Myelin Damage in the Rat Spinal Cord

et al. 2015

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“…The telemetry measures were selected based on prior evidence that parenteral injection of opioids causes hyperthermia and increased locomotor activity in both rats and mice. For example, intravenous morphine (6 mg/kg) increased the rectal temperature of anesthetized rats (El Bitar et al, 2016), as did intrathecal morphine (1-15 ug) in freely moving male Wistar rats measured with telemetry (Safrany-Fark et al, 2015). Both morphine and oxycodone produce hyperthermia when injected subcutaneously in rats (Bhalla et al, 2011).…”

Section: Introductionmentioning

confidence: 95%

A vapor exposure method for delivering heroin alters nociception, body temperature and spontaneous activity in female and male rats

Gutierrez

Creehan

Taffe

2021

Journal of Neuroscience Methods

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Background:The ongoing crisis related to non-medical use of opioids makes it of continued importance to understand the risk factors for opioid addiction, the behavioral and neurobiological consequences of opioid exposure and to seek potential avenues for therapy.Pre-clinical rodent models have been critical to advancing understanding of opioid consequences for decades, but have been mostly limited to drug delivery by injection or by oral dosing. Inhalation, a significant route for many human users, has not been as well-established. Method:We adapted an e-cigarette based exposure system, previously shown efficacious for delivery of other drugs to rats, to deliver heroin vapor. Effects in vivo were assessed in male and female Sprague-Dawley rats using a warm-water assay for anti-nociception and an implanted radiotelemetry system for evaluating changes in body temperature and spontaneous activity rate.Results: Inhalation of vapor created by heroin 100 mg/mL in the propylene glycol (PG) vehicle significantly slowed tail-withdrawal from a 52°C water bath, bi-phasically altered activity, and increased temperature in male and female rats. Inhalation of heroin 50 mg/mL for 15 minutes produced significant effects, as the lower bound on efficacy, whereas inhalation of heroin 100 mg/mL for 30 minutes produced robust effects across all endpoints and groups. Conclusions:This work shows that e-cigarette devices deliver psychoactive doses of heroin to rats, using concentrations of ~50-100 mg/mL and inhalation durations of 15-30 minutes. This technique may be useful to assess the health consequences of inhaled heroin and other opioid drugs.

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“…There are extensive data describing the interaction between the kynurenine and the endogenous opioid system [ 60 , 163 , 164 , 165 , 166 , 167 ]. It has also been demonstrated that KYNA and its analog KA1 can indirectly alter the G-protein signaling of opioid receptors through the NMDA receptor depending on the opioid receptor type (μ, κ or δ) and brain region (cortex or striatum) [ 168 , 169 ].…”

Section: Known and Potential Functional Interactions Betweenthe Enmentioning

confidence: 99%

Interactions between the Kynurenine and the Endocannabinoid System with Special Emphasis on Migraine

Nagy-Grócz

Zádor

Dvorácskó

et al. 2017

IJMS

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Both the kynurenine and the endocannabinoid systems are involved in several neurological disorders, such as migraine and there are increasing number of reports demonstrating that there are interactions of two systems. Although their cooperation has not yet been implicated in migraine, there are reports suggesting this possibility. Additionally, the individual role of the endocannabinoid and kynurenine system in migraine is reviewed here first, focusing on endocannabinoids, kynurenine metabolites, in particular kynurenic acid. Finally, the function of NMDA and cannabinoid receptors in the trigeminal system—which has a crucial role in the pathomechanisms of migraine—will also be discussed. The interaction of the endocannabinoid and kynurenine system has been demonstrated to be therapeutically relevant in a number of pathological conditions, such as cannabis addiction, psychosis, schizophrenia and epilepsy. Accordingly, the cross-talk of these two systems may imply potential mechanisms related to migraine, and may offer new approaches to manage the treatment of this neurological disorder.

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Telemetry monitoring for non-invasive assessment of changes in core temperature after spinal drug administration in freely moving rats

Cited by 7 publications

References 34 publications

Prolonged Subdural Infusion of Kynurenic Acid Is Associated with Dose-Dependent Myelin Damage in the Rat Spinal Cord

Prolonged Subdural Infusion of Kynurenic Acid Is Associated with Dose-Dependent Myelin Damage in the Rat Spinal Cord

A vapor exposure method for delivering heroin alters nociception, body temperature and spontaneous activity in female and male rats

Interactions between the Kynurenine and the Endocannabinoid System with Special Emphasis on Migraine

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