BACKGROUND: Neurosteroids are investigated as effective antidotes for the poisoning induced by tetramethylenedisulfotetramine (TMDT) as well as treatments for epileptic spasms during infancy. Both these conditions are quite resistant to pharmacotherapy; thus, a search for new treatments is warranted. METHODS: In this study, we determined the efficacy of two novel neurosteroids, pregnanolone glutamate (PAG) and pregnanolone pyroglutamate (PPG), and tested these drugs in doses of 1-10 mg/kg (ip) against the TMDT syndrome and in our rodent model of infantile spasms. RESULTS: Only PPG in doses 5 and 10 mg/kg suppressed the severity of the TMDT syndrome and TMDT-induced lethality, while the 1 mg/kg dose was without an effect. Interestingly, the 1 mg/kg dose of PPG in combination with 1 mg/kg of diazepam was also effective against TMDT poisoning. Neither PAG nor PPG were effective against experimental spasms in the N-methyl-D-aspartate (NMDA)-triggered model of infantile spasms. CONCLUSIONS: While evidence suggests that PAG can act through multiple actions which include allosteric inhibition of NMDA-induced and glycine receptor-evoked currents as well as augmentation of ɣ-aminobutyric acid subtype A (GABAA) receptor-induced currents, the agent appears to neither have the appropriate mechanistic signature for activity in the infantile spasm model, nor the adequate potency, relative to PPG, for ameliorating the TMDT syndrome. The full mechanisms of action of PPG, which may become a potent TMDT antidote either alone or in combination with diazepam are yet unknown and thus require further investigation.

• Klíčová slova
• Antidote, Neurosteroids, Neurotoxicity, Severe seizures, Tetramethylenedisulfotetramine,
• MeSH
• diazepam farmakologie   MeSH
• hlodavci MeSH
• křeče u dětí * chemicky indukované   farmakoterapie   MeSH
• kyselina glutamová MeSH
• kyselina pyrrolidonkarboxylová MeSH
• N-methylaspartát toxicita   terapeutické užití   MeSH
• neurosteroidy * MeSH
• neurotoxické syndromy * MeSH
• pregnanolon škodlivé účinky   MeSH
• spasmus MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• diazepam MeSH
• kyselina glutamová MeSH
• kyselina pyrrolidonkarboxylová MeSH
• N-methylaspartát MeSH
• neurosteroidy * MeSH
• pregnanolon MeSH
• tetramethylenedisulfotetramine MeSH Prohlížeč

Pregnanolone glutamate (PA-G) is a neuroactive steroid that has been previously demonstrated to be a potent neuroprotective compound in several biological models in vivo. Our in vitro experiments identified PA-G as an inhibitor of N-methyl-D-aspartate receptors and a potentiator of γ-aminobutyric acid receptors (GABAARs). In this study, we addressed the hypothesis that combined GABAAR potentiation and NMDAR antagonism could afford a potent anticonvulsant effect. Our results demonstrated the strong age-related anticonvulsive effect of PA-G in a model of pentylenetetrazol-induced seizures. PA-G significantly decreased seizure severity in 12-day-old animals, but only after the highest dose in 25-day-old animals. Interestingly, the anticonvulsant effect of PA-G differed both qualitatively and quantitatively from that of zuranolone, an investigational neurosteroid acting as a potent positive allosteric modulator of GABAARs. Next, we identified 17-hydroxy-pregnanolone (17-OH-PA) as a major metabolite of PA-G in 12-day-old animals. Finally, the administration of PA-G demonstrated direct modulation of unexpected neurosteroid levels, namely pregnenolone and dehydroepiandrosterone sulfate. These results suggest that compound PA-G might be a pro-drug of 17-OH-PA, a neurosteroid with a promising neuroprotective effect with an unknown mechanism of action that may represent an attractive target for studying perinatal neural diseases.

• Klíčová slova
• GABA, NMDA, anticonvulsant, metabolomics, neurosteroids, zuranolone,
• Publikační typ
• časopisecké články MeSH

Evidence from clinical and preclinical studies implicates dysfunction of N-methyl-D-aspartate receptors (NMDARs) in schizophrenia progression and symptoms. We investigated the antipsychotic effect of two neuroactive steroids in an animal model of schizophrenia induced by systemic application of MK-801. The neuroactive steroids differ in their mechanism of action at NMDARs. MS-249 is positive, while PA-Glu is a negative allosteric NMDAR modulator. We hypothesized that the positive NMDA receptor modulator would attenuate deficits caused by MK-801 co-application more effectively than PA-Glu. The rats were tested in a battery of tests assessing spontaneous locomotion, anxiety and cognition. Contrary to our expectations, PA-Glu exhibited a superior antipsychotic effect to MS-249. The performance of MS-249-treated rats in cognitive tests differed depending on the level of stress the rats were exposed to during test sessions. In particular, with the increasing severity of stress exposure, the performance of animals worsened. Our results demonstrate that enhancement of NMDAR function may result in unspecific behavioral responses. Positive NMDAR modulation can influence other neurobiological processes besides memory formation, such as anxiety and response to stress.

• Klíčová slova
• MK-801, anxiety, cognition, neurosteroids, schizophrenia, stress,
• MeSH
• antipsychotika farmakologie   MeSH
• bicyklické sloučeniny heterocyklické metabolismus   MeSH
• chování zvířat účinky léků   MeSH
• dizocilpinmaleát farmakologie   MeSH
• HEK293 buňky MeSH
• krysa rodu Rattus MeSH
• lidé MeSH
• modely nemocí na zvířatech MeSH
• potkani Long-Evans MeSH
• potkani Wistar MeSH
• pregnenolon metabolismus   farmakologie   MeSH
• receptory N-methyl-D-aspartátu antagonisté a inhibitory   metabolismus   MeSH
• schizofrenie farmakoterapie   metabolismus   MeSH
• steroidy farmakologie   MeSH
• test vyvýšeného křížového bludiště MeSH
• úleková reakce účinky léků   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• lidé MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• antipsychotika MeSH
• bicyklické sloučeniny heterocyklické MeSH
• dizocilpinmaleát MeSH
• pregnenolon MeSH
• pregnenolone sulfate MeSH Prohlížeč
• receptory N-methyl-D-aspartátu MeSH
• steroidy MeSH
• tert-butylbicyclophosphorothionate MeSH Prohlížeč

Herein, we report the synthesis, structure-activity relationship study, and biological evaluation of neurosteroid inhibitors of N-methyl-D-aspartate receptors (NMDARs) receptors that employ an amide structural motif, relative to pregnanolone glutamate (PAG) - a compound with neuroprotective properties. All compounds were found to be more potent NMDAR inhibitors (IC50 values varying from 1.4 to 21.7 μM) than PAG (IC50 = 51.7 μM). Selected compound 6 was evaluated for its NMDAR subtype selectivity and its ability to inhibit AMPAR/GABAR responses. Compound 6 inhibits the NMDARs (8.3 receptors (8.3 ± 2.1 μM) more strongly than it does at the GABAR and AMPARs (17.0 receptors (17.0 ± 0.2 μM and 276.4 ± 178.7 μM, respectively). In addition, compound 6 (10 μM) decreases the frequency of action potentials recorded in cultured hippocampal neurons. Next, compounds 3, 5-7, 9, and 10 were not associated with mitotoxicity, hepatotoxicity nor ROS induction. Lastly, we were able to show that all compounds have improved rat and human plasma stability over PAG.

• Klíčová slova
• NMDA receptor, amide, neurosteroid, plasma stability, structure-activity relationship,
• Publikační typ
• časopisecké články MeSH

• Klíčová slova
• animal models, clinical studies, cognition, neuropsychiatric disorders, preclinical studies,
• Publikační typ
• časopisecké články MeSH