Discovery of aryl sulfonamide-selective Nav1.7 inhibitors with a highly hydrophobic ethanoanthracene core.

Nav1.7 channels are mainly distributed in the peripheral nervous system. Blockade of Nav1.7 channels with small-molecule inhibitors in humans might provide pain relief without affecting the central nervous system. Based on the facts that many reported Nav1.7-selective inhibitors contain aryl sulfonamide fragments, as well as a tricyclic antidepressant, maprotiline, has been found to inhibit Nav1.7 channels, we designed and synthesized a series of compounds with ethanoanthracene and aryl sulfonamide moieties. Their inhibitory activity on sodium channels were detected with electrophysiological techniques. We found that compound 10o potently inhibited Nav1.7 channels stably expressed in HEK293 cells (IC50 = 0.64 ± 0.30 nmol/L) and displayed a high Nav1.7/Nav1.5 selectivity. In mouse small-sized dorsal root ganglion neurons, compound 10o (10, 100 nmol/L) dose-dependently decreased the sodium currents and dramatically suppressed depolarizing current-elicited neuronal discharge. Preliminary in vivo experiments showed that compound 10o possessed good analgesic activity: in a mouse visceral pain model, administration of compound 10o (30-100 mg/kg, i.p.) effectively and dose-dependently suppressed acetic acid-induced writhing.

Seguridad en el uso de antidepresivos: hiponatremia inducida con vortioxetina a propósito de un caso / Safety in the use of antidepressants: vortioxetine-induce hyponatremia in a case report

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Further studies on anti-inflammatory activity of maprotiline in carrageenan-induced paw edema in rat.

Antidepressant drugs are commonly used for treatment of different medical disorders besides of psychiatric diseases. Accumulating evidence suggests that antidepressants exhibit anti-inflammatory activity in vivo and in vitro conditions, but the mechanisms of this property are not clear very well. In our earlier work, we demonstrated that i.c.v. and i.p. injection of maprotiline, as an antidepressant, decreased paw edema at the fourth hour after subplantar injection of carrageenan. Therefore, this work was undertaken to investigate anti-inflammatory effects of maprotiline in more details. Our results verified that i.p. (25 and 50 mg/kg) and i.c.v. (100 µg/rat) application of maprotiline significantly reduced paw edema at 1, 2, 3 and 4 h intervals after carrageenan challenge. Pathological examinations and MPO activity also showed that both i.p. and i.c.v. maprotiline considerably inhibited infiltration of PMN leucocytes into the inflamed paws. Additionally, i.p. and i.c.v. maprotiline at all applied doses noticeably declined levels of IL-1ß into the site of inflammation, while only i.p. maprotiline at a dose of 50 mg/kg significantly decreased TNF-α levels in the carrageenan-injected paws. These results confirmed anti-edematogenic activity of i.p. and i.c.v. maprotiline in the carrageenan induced paw edema model and showed that these properties of maprotiline might be mediated through inhibition of PMN infiltration and release of IL-1ß and TNF-α.

Mechanism of maprotiline-induced apoptosis: role of [Ca2+](i), ERK, JNK and caspase-3 signaling pathways.

Antidepressants are generally used for treatment of various mood and anxiety disorders. Several studies have shown the anti-tumor and cytotoxic activities of some antidepressants, but the underlying mechanisms were unclear. Maprotiline is a tetracyclic antidepressant and possesses a highly selective norepinephrine reuptake ability. We found that maprotiline decreased cell viability in a concentration- and time-dependent manner in Neuro-2a cells. Maprotiline induced apoptosis and increased caspase-3 activation. The activation of caspase-3 by maprotiline appears to depend on the activation of JNK and the inactivation of ERK. Maprotiline also induced [Ca(2+)](i) increases which involved the mobilization of intracellular Ca(2+) stored in the endoplasmic reticulum. Pretreatment with BAPTA/AM, a Ca(2+) chelator, suppressed maprotiline-induced ERK phosphorylation, enhanced caspase-3 activation and increased maprotiline-induced apoptosis. In conclusion, maprotiline induced apoptosis in Neuro-2a cells through activation of JNK-associated caspase-3 pathways. Maprotiline also evoked an anti-apoptotic response that was both Ca(2+)- and ERK-dependent.

Antidepressant stimulation of CDP-diacylglycerol synthesis does not require monoamine reuptake inhibition.

BACKGROUND: Recent studies demonstrate that diverse antidepressant agents increase the cellular production of the nucleolipid CDP-diacylglycerol and its synthetic derivative, phosphatidylinositol, in depression-relevant brain regions. Pharmacological blockade of downstream phosphatidylinositide signaling disrupted the behavioral antidepressant effects in rats. However, the nucleolipid responses were resistant to inhibition by serotonin receptor antagonists, even though antidepressant-facilitated inositol phosphate accumulation was blocked. Could the neurochemical effects be additional to the known effects of the drugs on monoamine transmitter transporters? To examine this question, we tested selected agents in serotonin-depleted brain tissues, in PC12 cells devoid of serotonin transporters, and on the enzymatic activity of brain CDP-diacylglycerol synthase - the enzyme that catalyzes the physiological synthesis of CDP-diacylglycerol. RESULTS: Imipramine, paroxetine, and maprotiline concentration-dependently increased the levels of CDP-diacylglycerol and phosphatidylinositides in PC12 cells. Rat forebrain tissues depleted of serotonin by pretreatment with p-chlorophenylalanine showed responses to imipramine or maprotiline that were comparable to respective responses from saline-injected controls. With fluoxetine, nucleolipid responses in the serotonin-depleted cortex or hippocampus were significantly reduced, but not abolished. Each drug significantly increased the enzymatic activity of CDP-diacylglycerol synthase following incubations with cortical or hippocampal brain tissues. CONCLUSION: Antidepressants probably induce the activity of CDP-diacylglycerol synthase leading to increased production of CDP-diacylglycerol and facilitation of downstream phosphatidylinositol synthesis. Phosphatidylinositol-dependent signaling cascades exert diverse salutary effects in neural cells, including facilitation of BDNF signaling and neurogenesis. Hence, the present findings should strengthen the notion that modulation of brain phosphatidylinositide signaling probably contributes to the molecular mechanism of diverse antidepressant medications.

The synergistic interaction between morphine and maprotiline after intrathecal injection in rats.

BACKGROUND: Antidepressant drugs act as potent inhibitors of norepinephrine and/or serotonin reuptake and are widely used with opioids for the treatment of chronic pain. The mechanism of this increased analgesic action is unclear. We compared the antinociceptive effects of the intrathecal administration of morphine with that of a nonselective (amitriptyline) or selective (maprotiline or citalopram) antidepressant drug using the thermal withdrawal test in rats. We also investigated the possible mechanisms involved in the interactions of these drugs. METHODS: Male Wistar rats were anesthetized with sevoflurane and administered morphine and antidepressant drugs, or saline, through intrathecal injection. The antinociceptive effect was evaluated using the thermal withdrawal test before and after drug administration. The time for the withdrawal reaction was expressed as percentage of maximum possible effect (MPE). Animals were also pretreated with yohimbine (a nonselective alpha2-adrenergic antagonist) and naloxone (a nonselective opioid antagonist) for mechanism of action studies. Pharmacologic interaction was evaluated using isobolographic analysis of simultaneous administration of fixed proportions of maprotiline and morphine. RESULTS: Single intrathecal administration of morphine (2 microg), amitriptiline (125 microg), citalopram (144 microg), and maprotiline (1.25 microg) produced 51.6% +/- 8.9%, 10.3% +/- 3.2%, 33.8% +/- 5.2%, and 48.5% +/- 9.2% MPE, respectively. The antinociceptive effect of morphine was increased when combined with amitriptyline (91.3% +/- 4.6% MPE) and maprotiline (86.9% +/- 9.2% MPE) but not with citalopram (40.6% +/- 4.6% MPE). Coadministration of maprotiline increased the antinociceptive duration of morphine by 4-fold (from 120 to 480 min), which was reversed by pretreatment with the alpha-2 adrenoceptor inhibitor, yohimbine, and the mu-type opioid receptor antagonist, naloxone. Isobolographic analysis demonstrated a synergistic interaction between morphine and maprotiline. CONCLUSIONS: Selective norepinephrine reuptake inhibitors can significantly increase the intensity and duration of morphine antinociceptive activity via both alpha(2)-adrenergic and opioid receptors. This interaction was not observed with the selective serotonin inhibitor, citalopram.

Lipidomic analyses of the mouse brain after antidepressant treatment: evidence for endogenous release of long-chain fatty acids?

Recently, there has been considerable interest in a possible link between changes in brain polyunsaturated fatty acids, neural membrane phospholipid degradation, serotonergic neurotransmission, and depression. The present study aims to examine effects of antidepressants on lipids in different regions of the brain at individual molecular species level, using the novel technique of lipidomics. Balb/C mice received daily intraperitoneal (i.p.) injections of 10 mg/kg of the antidepressants maprotiline, fluoxetine and paroxetine for 4 wk. The prefrontal cortex, hippocampus, striatum and cerebellum were harvested, and lipid profiles compared to those of saline-injected mice. Treatment with maprotiline and paroxetine, but not fluoxetine, resulted in significant decreases in phosphatidylcholine (PC) species, PC36:1, PC38:3, PC40:2p, PC40:6, PC40:5, PC42:7p, PC42:6p and PC42:5p in the prefrontal neocortex. The decreases in phospholipids were accompanied by increases in lysophospholipid species, lysoPC16:0, lysoPC18:2 and lysoPC18:0 in the prefrontal cortex, indicating increase in phospholipase A2 activity and possible release of long-chain fatty acids. Maprotiline and paroxetine treatment also resulted in decreases in sphingomyelin and increases in several ceramide species in the prefrontal cortex. It is postulated that endogenous release of long-chain fatty acids may be related to the mechanism of action of maprotiline and paroxetine.

Mouse strain differences in the unpredictable chronic mild stress: a four-antidepressant survey.

There have been few comparisons of strains and antidepressants in the unpredictable chronic mild stress (UCMS) paradigm in mice. This study was undertaken to determine the influence of such factors using four antidepressants drugs including the tricyclics imipramine (20 mg/(kgday)) and desipramine (10 mg/(kgday)), the tetracyclic maprotiline (20 mg/(kgday)) and the selective serotonin reuptake inhibitor (SSRI) fluoxetine (10mg/(kgday)) in both Swiss and BALB/c mice. A 6-week UCMS regimen induced deterioration of the coat state and decreased grooming behaviours in the splash test in BALB/c mice but not Swiss mice. The four antidepressants reversed the UCMS-induced effects in BALB/c mice in both measures. However, imipramine and fluoxetine reached significance in the splash test while desipramine and maprotiline displayed only a trend. In conclusion, these results emphasize that BALB/c mice are more sensitive than Swiss mice for studying the effects of the UCMS model as well as for testing antidepressant-like properties.

Acute effects of maprotiline on learning, anxiety, activity and analgesia in male and female mice.

The acute effects of maprotiline (2.5, 5, 10, 15, 20 or 25 mg/kg) on learning, anxiety, activity and analgesia in male and female mice were evaluated. In addition to inhibitory avoidance learning, anxiety and locomotor activity were measured in the same animals using an elevated plus-maze. A study of the acute effects of maprotiline (15, 20 or 25 mg/kg) on analgesia was carried out in naive animals of both sexes. Maprotiline impaired inhibitory avoidance at doses of 15, 20 or 25 mg/kg. The highest dose produced an anxiolytic effect in females, and the doses of 20 and 25 mg/kg reduced locomotor activity. Analgesia was observed with the highest dose. The impairment of inhibitory avoidance by maprotiline would seem to be independent of the drug's influence on anxiety, is not shadowed by an instrumental performance deficit and, at least in the case of the highest dose, could be influenced by the drug's effects on analgesia. It is hypothesized that acquisition is the memory process principally affected by maprotiline, and in particular stimuli processing. The lack of sex differences in the effects of maprotiline on inhibitory avoidance supports the generalization of findings previously obtained only in males.

[Current views on migraine and anti-migraine preparations]. / Sovremennye predstavleniia o migreni i mekhanizmakh deistviia sredstv dlia ee lecheniia i profilaktiki.

On the basis of comprehensive experimental and clinical research the authors defined a variety of migraine-related mechanisms and schemes of migraine-correction by drugs, which should be both of the vascular- and general-actions to ensure an effective medication.

Current perception thresholds of patients with long-term administration of maprotiline.

The purpose of this study was to evaluate sensory nerve function using current perception thresholds (CPTs) in patients who were administrated maprotiline. Twelve patients with post-herpetic neuralgia and 20 control subjects were studied. The patients with post-herpetic neuralgia were given a daily dose of 60 mg of maprotiline and were maintained at the same dose for 6 months. Twenty control subjects were randomly selected from healthy volunteers. ACPT test was used for quantitative assessment of A beta, A sigma, and C fiber transmission, which are associated with pain, by three (2000, 250, and 5 Hz) different frequencies of electric stimulation. CPTs of 5, 250, and 2000 Hz in patients with post-herpetic neuralgia 2 months after administration of maprotiline were 141.7 +/- 17.3 for 5 Hz, 120.8 +/- 12.9 for 250 Hz, and 256.4 +/- 18.0 for 2000 Hz, which were significantly (P < 0.01) higher than those (67.0 +/- 9.1 for 5 Hz, 73.4 +/- 7.0 for 250 Hz, and 191.3 +/- 20.2 for 2000 Hz) before treatment and than those (35.3 +/- 15.8, 62.0 +/- 18.9, and 198.9 +/- 15.8) of control subjects. An increase in CPT for 5 Hz at 2 months after administration of maprotiline correlated (r = 0.71, p = 0.01) with a decrease in pain score. There were no correlations between an increase in CPT and changes in Hamilton Depression Scale (HAMD) values until 3 months after maprotiline treatment. However, we found that an increase in CPT for 5 Hz at 6 months after maprotiline treatment correlated (r = 0.68, p = 0.015) with a decrease in HAMD values. In conclusion, administration of 60 mg maprotiline significantly increased current perception thresholds at 2 months after the administration.

Differential effects of K(ATP) channel blockers on [(3)H]-noradrenaline overflow after short- and long-term exposure to (+)-oxaprotiline or desipramine.

To test whether prolonged uptake blockade can lead to changes in the function of ATP-dependent potassium (K(ATP)) channels we investigated in rat neocortex slices the effects of K(ATP) channel blockers on electrically evoked [(3)H]-noradrenaline ([(3)H]-NA) overflow after short- (45 min) and long-term (210 min) exposure to the NA uptake blockers (+)-oxaprotiline or desipramine (1 microM each). The K(ATP) channel blocker glibenclamide (1 micro M) increased the evoked [(3)H]-NA overflow by 42% after short-term uptake inhibition. This effect was confirmed by tolbutamide and glipizide, two other K(ATP) channel antagonists. The evoked [(3)H]-NA overflow was enhanced by 73% following short-term uptake blockade (15 min) and by 110% following long-term blockade (180 min). After long-term blockade (210 min), however, glibenclamide failed to further enhance the overflow of [(3)H]-NA. The alpha(2)-autoreceptor-mediated feedback control was not involved in the glibenclamide-induced increase in [(3)H]-NA overflow after short-term uptake blockade or in the increase in [(3)H]-NA overflow due to long-term uptake blockade per se. The Na(+)/K(+)-ATPase inhibitor ouabain diminished the glibenclamide-induced enhancement of [(3)H]-NA overflow after short-term uptake blockade, suggesting that an operative Na(+)/K(+)-ATPase is the prerequisite of activation of K(ATP) channels. These results suggest that short-term uptake blockade activates the Na(+)/K(+)-ATPase, thereby reducing intracellular ATP which allows transient opening of K(ATP) channels. Activation of the Na(+)/K(+)-ATPase may increase the Na(+) gradient, probably over the membrane of noradrenergic nerve terminals. The resulting hyperpolarisation leads to inhibition of the evoked overflow which can be reversed, i.e. enhanced, by K(ATP) channel blockers. In contrast, longer lasting uptake blockade seems to reduce the activity of the Na(+)/K(+)-ATPase and hence the consumption of ATP. As a consequence, reduced Na(+) and K(+) gradients may facilitate transmitter release. Closure of K(ATP) channels by accumulating ATP may further promote membrane depolarisation and transmitter release. The unexpected effect of longer exposure to uptake blockers could be somehow related to the clinical time latency of the antidepressant efficacy of monoamine uptake blockers.

Trimipramine and maprotiline plasma levels during combined treatment with moclobemide in therapy-resistant depression.

In an open pilot study of 21 therapy-resistant depressive inpatients, plasma levels of antidepressants were determined during treatment with a combination of moclobemide/ trimipramine (n = 15) and moclobemide/maprotiline (n = 6). After combined administration of trimipramine and moclobemide (MCB), a significant increase in the plasma level of trimipramine (39%) was observed. After combination of maprotiline with moclobemide, maprotiline levels were increased (25%, n.s.). The results show that moclobemide, as an inhibitor of isoenzymes of the cytochrome P 450 oxidase, can cause increases in the plasma levels of tricyclic and tetracyclic antidepressants. No correlation between the serum level of the antidepressants and treatment outcome was found in this open study.

Dose escalation vs. continued doses of paroxetine and maprotiline: a prospective study in depressed out-patients with inadequate treatment response.

In view of the fact that controlled prospective studies on the benefits of dose escalation of the selective serotonin re-uptake inhibitor (SSRI) paroxetine are lacking, we conducted a double-blind, randomized, parallel-group multicentre study designed to compare the possible benefits of dose escalation of paroxetine and maprotiline in patients suffering from major or minor depression according to modified Research Diagnostic Criteria (RDC) with inadequate treatment response. The study sample consisted of 544 out-patients with different degrees of severity of depression. Patients received either 20 mg paroxetine (n = 271) or 100 mg maprotiline (n = 273) for the first 3 weeks in a double-blind manner. Response after 3 weeks was defined using explicit operationalized criteria. Patients with inadequate treatment response (paroxetine group, n = 86; maprotiline group, n = 88) were again randomized to either continuation of the previous dosage (paroxetine, n = 36; maprotiline, n = 48) or increased doses, i.e. 40 mg paroxetine (n = 50) or 150 mg maprotiline (n = 40), respectively. Intention-to-treat and completer analyses were performed. Defining response as a reduction in Hamilton Depression Rating Scale (17-item version) (HAMD-17) score of at least 50% from baseline, no significant benefits of dose escalation were found for either paroxetine or maprotiline. Stratification according to baseline severity of depression also revealed no significant benefits of dose escalation. After dose escalation, new adverse events that had not been present during treatment with lower doses rarely occurred. Our results support the view that a dose of 20 mg paroxetine is optimal for the acute treatment of depression in the majority of patients.

[Maprotiline versus fluvoxamine: comparison of their effects on the hypothalamo-hypophyseal-thyroid axis]. / Maprotiline versus fluvoxamine: comparaison entre leurs actions sur l'axe hypothalamo-hypophyso-thyroïdien.

The TRH test has been used in psychiatry these last 20 years. One of the most promising results is that concerning the possibility to use it to identify the best moment to stop a treatment after clinical recovery of the depressive episode. For that it is necessary to demonstrate an absence of intrinsic action of antidepressants on the HPT axis physiology. This overt, randomized study has compared the actions on T3, T4, basal TSH and its response to the TRH test after 75 mg/day of maprotiline and 100 mg/day of fluvoxamine, both administrated in depressed patients during 28 days. Forty patients (20 men and 20 women) were studied, 20 patients per treatment. The inclusion criteria were those of DSM III-R for major depression and dysthymia as well a minimum score of 25 at MADRS scale. Blood samples for T3, T4 and basal TSH dosages were made before TRH intranasal administration (2 mg) at days 1 and 28 of the treatment. We haven't observed any difference before treatment between the 2 groups for clinical and biological studied parameters. After treatment both antidepressants produced equivalent improvement of depression evaluated by MADRS (fluvoxamine:dMADRS = 16.95 +/- 7.11; maprotiline: dMADRS = 17.10 +/- 6.84. t = 0.07, NS). T3 and T4 variations between the beginning and the end of the study weren't also significantly different between the 2 groups. Basal TSH was increased in the maprotiline group but decreased in the fluvoxamine group resulting in a significant difference (fluvoxamine: dTSH = 0.31 +/- 0.76 mUI/l. Maprotiline : dTSH = -0.23 +/- 0.66 mUI/l. t = 2.40, p < 0.02). The TSH response to TRH was decreased in the fluvoxamine group (ddTSH = 0.24 +/- 6.65 mUI/l. dAUC = 103.98 +/- 596.84 mUI/l) while it was increased in the maprotiline group (ddTSH = -3.59 +/- 5.88 mUI/l. dAUC = -355.80 +/- 505.67 mUI.min/l). The difference between the 2 treatments was not significant when evaluated by ddTSH (t = 1.53, NS) but it became significant if evaluated by dAUC (t = 2.63, p < 0.01). As we could demonstrate an absence of influence of the clinical evolution between both groups in the hormonal variations observed, we concluded to a intrinsic difference action on HPT axis between fluvoxamine and maprotiline. This difference could be linked to the different aminergic action of these 2 antidepressants.

Effects of fluoxetine and maprotiline on functional recovery in poststroke hemiplegic patients undergoing rehabilitation therapy.

BACKGROUND AND PURPOSE: In animals, drugs that increase brain amine concentrations influence the rate and degree of recovery from cortical lesions. It is therefore conceivable that antidepressants may influence outcome after ischemic brain injury in humans. We evaluated the effects of the norepinephrine reuptake blocker maprotiline and the serotonin reuptake blocker fluoxetine on the motor/functional capacities of poststroke patients undergoing physical therapy. METHODS: Fifty-two severely disabled hemiplegic subjects were randomly assigned to three treatment groups; during 3 months of physical therapy, patients were treated with placebo, maprotiline (150 mg/d), or fluoxetine (20 mg/d). Before and at the end of the observation period, we assessed activities of daily living by the Barthel Index, degree of neurological deficit by a neurological scale for hemiplegic subjects, and depressive symptomatology by the Hamilton Depression Rating Scale. RESULTS: The diverse treatments ameliorated walking and activities of daily living capacities to different extents. The greatest improvements were observed in the fluoxetine-treated group and the lowest in the maprotiline-treated group. Furthermore, fluoxetine yielded a significantly larger number of patients with good recovery compared with maprotiline or placebo. These effects of the drugs were not related to their efficacy in treating depressive symptoms. CONCLUSIONS: Fluoxetine may facilitate or, alternatively, maprotiline may hinder recovery in poststroke patients undergoing rehabilitation. The effects of fluoxetine as an adjunct to physical therapy warrant further investigation, since treatment with fluoxetine may result in a better functional outcome from stroke than physical therapy alone.