Effects of different doses of remimazolam on hemodynamics during general anesthesia in patients with septic shock.

OBJECTIVE: The stability of hemodynamics plays a vital role in the process of anesthesia induction for patients with septic shock. As a new-type benzodiazepine, remimazolam has numerous advantages, including rapid induction, rapid recovery, stable hemodynamics, and mild respiratory depression. Nevertheless, reports about the effects of remimazolam on hemodynamics in patients with septic shock are still limited. The study aimed to evaluate the effects that different doses of remimazolam have on hemodynamics in inducing general anesthesia in patients with septic shock. PATIENTS AND METHODS: Admitted to the intensive care unit of our hospital from January 2023 to June 2023, 75 patients with septic shock caused by acute appendicitis-induced sepsis were selected as observation subjects. They were randomly assigned to receive low-dose [0.2 mg/(kg·h)], medium-dose [0.3 mg/(kg·h)], and high-dose [0.4 mg/(kg·h)] remimazolam by using a random number table, with 25 patients in each group. Their intraoperative conditions were recorded, including operation duration, intraoperative hemorrhage volume, intraoperative transfusion volume, and decannulation time. Hemodynamic parameters, including mean arterial pressure (MAP), heart rate (HR), cardiac index (CI), and stoke volume index (SVI) were collected at seven-time points (T0: before induction; T1: before intubation; T2: after intubation; T3: the start of operation; T4: 15 min after operation; T5: 30 min after operation; T6: the end of operation). We also compared hepatic and renal function indexes, including blood urea nitrogen (BUN), serum creatinine (sCr), procalcitonin (PCT), white blood cells (WBC), tumor necrosis factor-α2 (TNF-α2), and Interleukin-6 (IL-6), of the three groups of patients before operation and 1, 3, 5, 7 days after operation. In addition, the incidence of adverse reactions in the three groups was recorded and compared. RESULTS: During remimazolam induction, the number of patients with intraoperative need for rescue remimazolam in the medium-dose and high-dose groups was significantly lower than in the low-dose group (p < 0.05). In terms of hemodynamic indexes, MAP in the high-dose group at T2 was lower than that at T0 (p < 0.05), and MAP at T2 was significantly lower in the high-dose group than that in the medium-dose group (p < 0.05). Furthermore, MAP at T4 in the medium-dose and high-dose groups declined compared with the low-dose group (p < 0.05). There were no significant differences in HR, CI, and SVI at different time points among the three groups (p > 0.05), but levels of HR and SVI decreased and CI increased after anesthesia compared with those before operation. Additionally, in comparison with the levels before operation, levels of sCR, BUN, PCT, WBC, TNF-α, and IL-6 were higher on postoperative days 1, 3 (p < 0.05) and lower on postoperative day 7 (p < 0.05). After the operation, both levels of BUN and sCR in the medium-dose and high-dose groups were lower than those in the low-dose group (p < 0.05). CONCLUSIONS: Remimazolam is safe and effective for inducing general anesthesia in patients with septic shock. Low, medium, and high doses of remimazolam can maintain a stable hemodynamic state, and the recovery of hepatic and renal function is certain to depend on the dose.

GABAergic mechanisms in alcohol dependence.

The target of alcohol's effect on the central nervous system has been sought for more than 50 years in the brain's GABA system. The behavioral and emotional effects of alcohol in humans and rodents are very similar to those of barbiturates and benzodiazepines, and GABAA receptors have been shown to be one of the sites of alcohol action. The mechanisms of GABAergic inhibition have been a hotspot of research but have turned out to be complex and controversial. Genetics support the involvement of some GABAA receptor subunits in the development of alcohol dependence and in alcohol use disorders (AUD). Since the effect of alcohol on the GABAA system resembles that of a GABAergic positive modulator, it may be possible to develop GABAergic drug treatments that could substitute for alcohol. The adaptation mechanisms of the GABA system and the plasticity of the brain are a big challenge for drug development: the drugs that act on GABAA receptors developed so far also may cause adaptation and development of additional addiction. Human polymorphisms should be studied further to get insight about how they affect receptor function, expression or other factors to make reasonable predictions/hypotheses about what non-addictive interventions would help in alcohol dependence and AUD.

A longitudinal MRI and TSPO PET-based investigation of brain region-specific neuroprotection by diazepam versus midazolam following organophosphate-induced seizures.

Acute poisoning with organophosphorus cholinesterase inhibitors (OPs), such as OP nerve agents and pesticides, can cause life threatening cholinergic crisis and status epilepticus (SE). Survivors often experience significant morbidity, including brain injury, acquired epilepsy, and cognitive deficits. Current medical countermeasures for acute OP poisoning include a benzodiazepine to mitigate seizures. Diazepam was long the benzodiazepine included in autoinjectors used to treat OP-induced seizures, but it is now being replaced in many guidelines by midazolam, which terminates seizures more quickly, particularly when administered intramuscularly. While a direct correlation between seizure duration and the extent of brain injury has been widely reported, there are limited data comparing the neuroprotective efficacy of diazepam versus midazolam following acute OP intoxication. To address this data gap, we used non-invasive imaging techniques to longitudinally quantify neuropathology in a rat model of acute intoxication with the OP diisopropylfluorophosphate (DFP) with and without post-exposure intervention with diazepam or midazolam. Magnetic resonance imaging (MRI) was used to monitor neuropathology and brain atrophy, while positron emission tomography (PET) with a radiotracer targeting translocator protein (TSPO) was utilized to assess neuroinflammation. Animals were scanned at 3, 7, 28, 65, 91, and 168 days post-DFP and imaging metrics were quantitated for the hippocampus, amygdala, piriform cortex, thalamus, cerebral cortex and lateral ventricles. In the DFP-intoxicated rat, neuroinflammation persisted for the duration of the study coincident with progressive atrophy and ongoing tissue remodeling. Benzodiazepines attenuated neuropathology in a region-dependent manner, but neither benzodiazepine was effective in attenuating long-term neuroinflammation as detected by TSPO PET. Diffusion MRI and TSPO PET metrics were highly correlated with seizure severity, and early MRI and PET metrics were positively correlated with long-term brain atrophy. Collectively, these results suggest that anti-seizure therapy alone is insufficient to prevent long-lasting neuroinflammation and tissue remodeling.

A Retrospective Evaluation of Adjunctive Phenobarbital vs. Benzodiazepine Alone for the Treatment of Moderate Alcohol Withdrawal in the Emergency Department.

BACKGROUND: Phenobarbital has been used in the emergency department (ED) as both a primary and adjunctive medication for alcohol withdrawal, but previous studies evaluating its impact on patient outcomes are limited by heterogenous symptom severity. OBJECTIVES: We compared the clinical outcomes of ED patients with moderate alcohol withdrawal who received phenobarbital, with or without benzodiazepines, with patients who received benzodiazepine treatment alone. METHODS: This is a retrospective cohort study conducted at a single academic medical center utilizing chart review of ED patients with moderate alcohol withdrawal between 2015 and 2020. Patient encounters were classified into two treatment categories based on medication treatment: phenobarbital alone or in combination with benzodiazepines vs. benzodiazepines alone. Chi-square test or Fisher's exact was used to analyze categorical variables and the Student's t-test for continuous data. RESULTS: Among the 287 encounters that met inclusion criteria, 100 received phenobarbital, compared with 187 that received benzodiazepines alone. Patients who received phenobarbital were provided significantly more lorazepam equivalents. There was a significant difference in the percentage of patient encounters that required admission to the hospital in the phenobarbital cohort compared with the benzodiazepine cohort (75% vs. 43.3%, p < 0.001). However, there was no difference in admission level of care to the floor (51.2% vs. 52.0%), stepdown (33.8% vs. 28%), or intensive care unit (15% vs. 20%), respectively. CONCLUSIONS: Patients who received phenobarbital for moderate alcohol withdrawal were more likely to be admitted to the hospital, but there was no difference in admission level of care when compared with patients who received benzodiazepines alone. Patients who received phenobarbital were provided greater lorazepam equivalents in the ED.

Comparison of the negative effect of remimazolam and propofol on cardiac contractility: Analysis of a randomised parallel-group trial and a preclinical ex vivo study.

Remimazolam is a newly developed ultra-short-acting benzodiazepine that exerts sedative effects. This study aimed to clarify the effects of remimazolam on cardiac contractility. In a randomised-parallel group trial, haemodynamic parameters were compared between propofol (n = 11) and remimazolam (n = 12) groups during the induction of general anaesthesia in patients undergoing non-cardiac surgery. In a preclinical study, the direct effects of remimazolam on cardiac contractility were also evaluated using isolated rat hearts. RNA sequence data obtained from rat and human hearts were analysed to assess the expression patterns of the cardiac γ-aminobutyric acid type A (GABAA ) receptor subunits. In a clinical study, the proportional change of the maximum rate of arterial pressure rise was milder during the study period in the remimazolam group (propofol: -52.6 [10.2] (mean [standard deviation])% vs. remimazolam: -39.7% [10.5%], p = 0.007). In a preclinical study, remimazolam did not exert a negative effect on left ventricle developed pressure, whereas propofol did exert a negative effect after bolus administration of a high dose (propofol: -26.9% [3.5%] vs. remimazolam: -1.1 [6.9%], p < 0.001). Analysis of the RNA sequence revealed a lack of γ subunits, which are part of the major benzodiazepine binding site of the GABAA receptor, in rat and human hearts. These results indicate that remimazolam does not have a direct negative effect on cardiac contractility, which might contribute to its milder effect on cardiac contractility during the induction of general anaesthesia. The expression patterns of cardiac GABAA receptor subunits might be associated with the unique pharmacokinetics of benzodiazepines in the heart.

Olanzapine's effects on hypothalamic transcriptomics and kinase activity.

Olanzapine is a second-generation antipsychotic that disrupts metabolism and is associated with an increased risk of type 2 diabetes. The hypothalamus is a key region in the control of whole-body metabolic homeostasis. The objective of the current study was to determine how acute peripheral olanzapine administration affects transcription and serine/threonine kinase activity in the hypothalamus. Hypothalamus samples from rats were collected following the pancreatic euglycemic clamp, thereby allowing us to study endpoints under steady state conditions for plasma glucose and insulin. Olanzapine stimulated pathways associated with inflammation, but diminished pathways associated with the capacity to combat endoplasmic reticulum stress and G protein-coupled receptor activity. These pathways represent potential targets to reduce the incidence of type 2 diabetes in patients taking antipsychotics.

Vascular effects of midazolam, flumazenil, and a novel imidazobenzodiazepine MP-III-058 on isolated rat aorta.

Hypotensive influences of benzodiazepines and other GABAA receptor ligands, recognized in clinical practice, seem to stem from the existence of "vascular" GABAA receptors in peripheral blood vessels, besides any mechanisms in the central and peripheral nervous systems. We aimed to further elucidate the vasodilatatory effects of ligands acting through GABAA receptors. Using immunohistochemistry, the rat aortic smooth muscle layer was found to express GABAA γ2 and α1-5 subunit proteins. To confirm the role of "vascular" GABAA receptors, we investigated the vascular effects of standard benzodiazepines, midazolam, and flumazenil, as well as the novel compound MP-III-058. Using two-electrode voltage clamp electrophysiology and radioligand binding assays, MP-III-058 was found to have modest binding but substantial functional selectivity for α5ß3γ2 over other αxß3γ2 GABAA receptors. Tissue bath assays revealed comparable vasodilatory effects of MP-III-058 and midazolam, both of which at 100 µmol/L concentrations had efficacy similar to prazosin. Flumazenil exhibited weak vasoactivity per se, but significantly prevented the relaxant effects of midazolam and MP-III-058. These studies indicate the existence of functional GABAA receptors in the rat aorta, where ligands exert vasodilatory effects by positive modulation of the benzodiazepine binding site, suggesting the potential for further quest for leads with optimized pharmacokinetic properties as prospective adjuvant vasodilators.

Target-controlled Infusion of Remimazolam in Healthy Volunteers Shows Some Acute Tolerance.

BACKGROUND: Remimazolam exhibits sedative properties by binding to γ-aminobutyric acid type A receptors. Remimazolam is administered as a bolus dose or continuous infusion, but has not been studied using target-controlled infusion (TCI). The study quantified the relationship between the remimazolam concentration, Modified Observer's Assessment of Alertness and Sedation (MOAAS) score, and bispectral index (BIS) using TCI. METHODS: The authors performed a three-period, crossover, dose-ranging clinical trial in 24 healthy volunteers using age and sex stratification. Data collected in the first period, where remimazolam was administered alone using a step-up and step-down TCI protocol, were used for this analysis. Remimazolam concentrations, MOAAS scores, and BIS values were collected at each step at steady state. Data were analyzed using nonlinear mixed-effects modeling methodology. RESULTS: The relationship between remimazolam, BIS, and MOAAS differed between step-up and step-down infusions at similar remimazolam target concentrations. Tolerance, driven by remimazolam or CNS7054, significantly improved overall model fit (P < 0.01) for both BIS and MOAAS models. After 30 min of repeated bolus dosing, mimicking the regimen in the label for procedural sedation, the BIS and probability of MOAAS 2/3 were predicted to be 54 (95% prediction interval, 44 to 67) and 2% (95% prediction interval, 0 to 32%) versus 58 (95% prediction interval, 48 to 70) and 8% (95% prediction interval, 0 to 36%) in a model without and with tolerance, respectively. After 60 min of continuous infusion, mimicking the regimen in the label for general anesthesia, the BIS and probability of MOAAS 0 were predicted to be 40 (95% prediction interval, 33 to 50) and 87% (95% prediction interval, 18 to 100%) versus 50 (95% prediction interval, 41 to 60) and 59% (95% prediction interval, 6 to 99%) in a model without and with tolerance, respectively. CONCLUSIONS: In this study, it was shown that remimazolam-induced sedation is prone to tolerance development, which is potentially mediated by the CNS7054 concentration. The clinical consequences are, however, limited in situations where remimazolam is titrated to effect.

The anthelmintic meclonazepam activates a schistosome transient receptor potential channel.

Parasitic flatworms cause various clinical and veterinary infections that impart a huge burden worldwide. The most clinically impactful infection is schistosomiasis, a neglected tropical disease caused by parasitic blood flukes. Schistosomiasis is treated with praziquantel (PZQ), an old drug introduced over 40 years ago. New drugs are urgently needed, as while PZQ is broadly effective it suffers from several limitations including poor efficacy against juvenile worms, which may prevent it from being completely curative. An old compound that retains efficacy against juvenile worms is the benzodiazepine meclonazepam (MCLZ). However, host side effects caused by benzodiazepines preclude development of MCLZ as a drug and MCLZ lacks an identified parasite target to catalyze rational drug design for engineering out human host activity. Here, we identify a transient receptor potential ion channel of the melastatin subfamily, named TRPMMCLZ, as a parasite target of MCLZ. MCLZ potently activates Schistosoma mansoni TRPMMCLZ through engagement of a binding pocket within the voltage-sensor-like domain of the ion channel to cause worm paralysis, tissue depolarization, and surface damage. TRPMMCLZ reproduces all known features of MCLZ action on schistosomes, including a lower activity versus Schistosoma japonicum, which is explained by a polymorphism within this voltage-sensor-like domain-binding pocket. TRPMMCLZ is distinct from the TRP channel targeted by PZQ (TRPMPZQ), with both anthelmintic chemotypes targeting unique parasite TRPM paralogs. This advances TRPMMCLZ as a novel druggable target that could circumvent any target-based resistance emerging in response to current mass drug administration campaigns centered on PZQ.

Sex Differences in Organophosphate Model of Benzodiazepine-Refractory Status Epilepticus and Neuronal Damage.

Sex differences are common in human epilepsy. Although men are more susceptible to seizure than women, the mechanisms underlying sex-specific vulnerabilities to seizure are unclear. The organophosphate (OP) diisopropylfluorophosphate (DFP) is known to cause neurotoxicity and status epilepticus (SE), a serious neurologic condition that causes prolonged seizures and brain damage. Current therapies for OP poisoning and SE do not consider neuronal variations between male and female brains. Therefore, we investigated sex-dependent differences in electrographic seizure activity and neuronal injury using the DFP model of refractory SE in rats. Electroencephalogram recordings were used to monitor DFP-induced SE, and the extent of brain injury was determined using fluoro-jade-B staining to detect cellular necrosis. After DFP exposure, we observed striking sex-dependent differences in SE and seizure activity patterns as well as protective responses to midazolam treatment. Following acute DFP exposure, male animals displayed more severe SE with intense epileptiform spiking and greater mortality than females. In contrast, we observed significantly more injured cells and cellular necrosis in the hippocampus and other brain regions in females than in males. We also observed extensive neuronal injury in the somatosensory cortex of males. The anticonvulsant effect of midazolam against SE was limited in this model and found to be similar in males and females. However, unlike males, females exhibited substantially more protection against neuronal damage after midazolam treatment. Overall, these results demonstrate significant sex-dependent differences in DFP-induced refractory SE and neuronal damage patterns, suggesting that it may be possible to develop sex-specific neuroprotective strategies for OP intoxication and refractory SE. SIGNIFICANCE STATEMENT: Sex-dependent differences in neurotoxicity and status epilepticus (SE) are key biological variables after organophosphate (OP) exposure. Here, we investigated sex-dependent differences in SE and brain injury after acute diisopropylfluorophosphate exposure. Male rats had more severe SE and less survival than females, while females had more neuronal damage. Females had more neuroprotection to midazolam than males, while both sexes had similar but partial anticonvulsant effects. These findings suggest that a sex-specific therapeutic approach may prevent neurological complications of OP-induced SE.

Discriminative-stimulus effects of cannabidiol oil in Sprague-Dawley rats.

Cannabidiol (CBD) is one of the major centrally active phytocannabinoid components of cannabis, and has been approved by the FDA only for the treatment of seizures associated with three rare disorders. It has also been touted as a potential treatment for anxiety in place of more traditional treatments like benzodiazepines. Although there is some evidence of anxiolytic effects of CBD, its suitability as a substitute for benzodiazepines is unknown. This experiment was designed to assess the extent to which CBD shares interoceptive discriminative-stimulus properties with the anxiolytic drug chlordiazepoxide (CDP), a benzodiazepine. In the present experiment, a range of doses (0-1569 mg/kg) of over-the-counter CBD oil was administered (i.g.) in male Sprague-Dawley rats trained to discriminate 5.6 mg/kg CDP from saline. Due to the long time-course effects of CBD, generalization tests were conducted at 90 and 120 min post-CBD administration. The two highest doses of CBD tested (1064 and 1569 mg/kg) were found to partially substitute for 5.6 mg/kg CDP, with mean percent responding on the CDP-associated lever reaching above 20% at time 2 (120 min post-CBD administration), suggesting that high doses of the over-the-counter CBD oils used in this experiment share interoceptive discriminative-stimulus properties to some degree with CDP. These results are novel in comparison to existing research into stimulus effects of CBD, in which substitution for benzodiazepines has not previously been observed.

Benzodiazepine Delorazepam Induces Locomotory Hyperactivity and Alterations in Pedal Mucus Texture in the Freshwater Gastropod Planorbarius corneus.

Benzodiazepines, psychotropic drugs, are ubiquitous in the aquatic environment due to over-consumption and inefficient removal by sewage treatment plants. Bioaccumulation with consequent behavioral and physiological effects has been reported in many aquatic species. However, the responses are species-specific and still poorly understood. To improve the knowledge, we exposed the freshwater snail Planorbarius corneus to 1, 5, or 10 µg/L of delorazepam, the most widely consumed benzodiazepine in Italy. Conventional behavioral tests were used to assess the effects on locomotor and feeding behavior. Histological and biochemical analyses were also performed to detect possible changes in the structure and composition of the foot mucus and glands. The results show a paradoxical response with reduced feeding activity and locomotor hyperactivity. Pedal mucus was altered in texture but not in composition, becoming particularly rich in fibrous collagen-like material, and a significant change in the protein composition was highlighted in the foot. In conclusion, exposure to delorazepam induces disinhibited behavior in Planorbarius corneus, potentially increasing the risk of predation, and an increase in mucus protein production, which, together with reduced feeding activity, would severely compromise energy resources.

Development of QSAR model based on Monte Carlo optimization for predicting GABAA receptor binding of newly emerging benzodiazepines.

Benzodiazepines and their derivatives belong to a category of new psychoactive substances that have been introduced into the continually expanding illicit market. However, there is a notable absence of available pharmacological data for these substances. To gain a deeper understanding of their pharmacology, we employed the Monte Carlo optimization conformation-independent method as a tool for developing QSAR models. These models were built using optimal molecular descriptors derived from both SMILES notation and molecular graph representations. The resulting QSAR model demonstrated robustness and a high degree of predictability, proving to be very reliable. Moreover, we were able to identify specific molecular fragments that exerted both positive and negative effects on binding activity. This discovery paves the way for the swift prediction of binding activity for emerging benzodiazepines, offering a faster and more cost-effective alternative to traditional in vitro/in vivo analyses.

[Inhibitory Effects and Mechanisms of Three Benzodiazepines on Helicobacter pylori].

Objective To explore the inhibitory effects and mechanisms of benzodiazepines on Helicobacter pylori (Hp).Methods The Hp international standard strain ATCC43504 was treated with benzodiazepines diazepam,midazolam,and remimazolam,respectively.The treatments with amoxicillin and clarithromycin were taken as the positive controls,and that with water for injection as the negative control.The inhibition zone of each drug was measured by the disk diffusion method.The minimum inhibitory concentration(MIC)and minimum bactericidal concentration(MBC)of each drug against Hp were determined.Hp suspension was configured and treated with diazepam and midazolam,respectively.The bacterial suspension without drug added was used as the control group.The concentration of K+ in each bacterial suspension was measured by an automatic biochemical analyzer before drug intervention(T0)and 1(T1),2(T2),3(T3),4(T4),5(T5),6(T6),and 7 h(T7)after intervention.Hp urease was extracted and treated with 1/2 MIC diazepam,1 MIC diazepam,2 MIC diazepam,1/2 MIC midazolam,1 MIC midazolam,2 MIC midazolam,1 mg/ml acetohydroxamic acid,and water for injection,respectively.The time required for the rise from pH 6.8 to pH 7.7 in each group was determined by the phenol red coloring method.Results The inhibition zones of diazepam,midazolam,remimazolam,amoxicillin,clarithromycin,and water for injection against Hp were 52.3,42.7,6.0,72.3,60.8,and 6.0 mm,respectively.Diazepam and midazolam showed the MIC of 12.5 µg/ml and 25.0 µg/ml and the MBC of 25 µg/ml and 50 µg/ml,respectively,to Hp.The concentrations of K+ in the diazepam,midazolam,and control groups increased during T1-T7 compared with those at T0(all P<0.01).The concentration of K+ in diazepam and midazolam groups during T1-T4 was higher than that in the control group(all P<0.01).The time of inhibiting urease activity in the 1/2 MIC diazepam,1 MIC diazepam,2 MIC diazepam,1/2 MIC midazolam,1 MIC midazolam,and 2 MIC midazolam groups was(39.86±5.11),(36.52±6.65),(38.58±4.83),(39.25±6.19),(36.36±4.61),and(35.81±6.18)min,respectively,which were shorter than that in the acetohydroxamic acid group(all P<0.01)and had no significance differences from that in the water for injection group(all P>0.05).Conclusion Diazepam and midazolam exerted inhibitory effects on Hp,which may be related to the cleavage of Hp cells rather than inhibiting urease.

The spectral slope as a marker of excitation/inhibition ratio and cognitive functioning in multiple sclerosis.

Multiple sclerosis (MS) is a neurodegenerative disease characterized by neuronal and synaptic loss, resulting in an imbalance of excitatory and inhibitory synaptic transmission and potentially cognitive impairment. Current methods for measuring the excitation/inhibition (E/I) ratio are mostly invasive, but recent research combining neurocomputational modeling with measurements of local field potentials has indicated that the slope with which the power spectrum of neuronal activity captured by electro- and/or magnetoencephalography rolls off, is a non-invasive biomarker of the E/I ratio. A steeper roll-off is associated with a stronger inhibition. This novel method can be applied to assess the E/I ratio in people with multiple sclerosis (pwMS), detect the effect of medication such as benzodiazepines, and explore its utility as a biomarker for cognition. We recruited 44 healthy control subjects and 95 pwMS who underwent resting-state magnetoencephalographic recordings. The 1/f spectral slope of the neural power spectra was calculated for each subject and for each brain region. As expected, the spectral slope was significantly steeper in pwMS treated with benzodiazepines (BZDs) compared to pwMS not receiving BZDs (p = .01). In the sub-cohort of pwMS not treated with BZDs, we observed a steeper slope in cognitively impaired pwMS compared to cognitively preserved pwMS (p = .01) and healthy subjects (p = .02). Furthermore, we observed a significant correlation between 1/f spectral slope and verbal and spatial working memory functioning in the brain regions located in the prefrontal and parietal cortex. In this study, we highlighted the value of the spectral slope in MS by quantifying the effect of benzodiazepines and by putting it forward as a potential biomarker of cognitive deficits in pwMS.

Effects of antipsychotics, haloperidol and olanzapine, on the expression of apoptosis-related genes in mouse mHippoE-2 cells and rat hippocampus.

Objective. Modified levels of pro- (caspase3, Bax) and anti-apoptotic (Bcl-2) regulatory proteins have been detected in certain brain areas of schizophrenic patients indicating a possible dysregulation of apoptosis. In the present study, effects of antipsychotics, haloperidol (HAL) and olanzapine (OLA), on the gene expression of caspase3 (casp3), Bax and Bcl-2 were studied in vitro in mouse hippocampal mHippoE-2 cell line and in vivo in the hippocampus of MK-801 animal schizophrenia model with the aim to provide evidence that antipsychotics may affect the activity of apoptosis-related markers. Methods. mHippoE-2 cells were incubated with MK-801 (20 µM), HAL (10 µM), and OLA (10 µM) alone or combined, MK-801+HAL/OLA, for 24, 48, and 72 h. Male Sprague Dawley rats were injected with saline or MK-801 (0.5 mg/kg) for 6 days and since the 7th day, they were treated with vehicle (VEH), HAL (1 mg/kg) or OLA (2 mg/kg) for the next 7 days. The casp3, Bax and Bcl-2 gene expression in mHippoE-2 cells and rat hippocampus was measured by RT-PCR. Results. In mHippoE-2 cells, casp3 gene expression was increased by MK-801 and OLA treatments alone for 48 h, HAL treatment alone for 24 and 72 h, and co-treatment with MK-801+OLA for 24 and 72 h compared to controls. HAL and OLA suppressed the stimulatory effect of MK-801 on casp3 mRNA levels in cells after 48 h of incubation. Bax mRNA levels in mHippoE-2 cells were decreased after HAL treatment for 24 and 48 h, and also after co-treatment with MK-801+HAL for 72 h. In vivo, MK-801 decreased mRNA levels of both pro-apoptotic markers, casp3 and Bax, in hippocampus of VEH-treated rats and Bax mRNA levels in hippocampus of HAL-treated animals. OLA reversed the inhibitory effect of MK-801 on casp3 expression in the VEH-treated animals. Neither MK-801 nor antipsychotics induced changes in the gene expression of anti-apoptotic marker Bcl-2 in mHippoE-2 cells as well as hippocampus of rats. Conclusions. The results of the present study demonstrate that antipsychotics, HAL and OLA, may affect mRNA levels of pro-apoptotic markers in hippocampal cells in vitro, but not in vivo. The obtained data do not clearly support the assumed potentiating role of MK-801 in inducing apoptosis in specific brain areas and a possible protective role of antipsychotics against induction of apoptosis. The obtained data may contribute to a deeper insight into the neurodevelopmental changes connected with schizophrenia.

Pharmaco-EEG analysis of ligands varying in selectivity for α1 subunit-containing GABAA receptors during the active phase in rats.

RATIONALE: Benzodiazepines are known to evoke changes in cortical electrophysiological activity that can be correlated with action at distinct γ-aminobutyric acid type A (GABAA) receptor subtypes. OBJECTIVES: We used electroencephalography (EEG) paired with electromyography (EMG) to evaluate the role of α1 subunit-containing GABAA receptors (α1GABAARs) in benzodiazepine-induced sedation and changes in EEG band frequencies during the active phase of the light/dark cycle. METHODS: Male Sprague-Dawley rats (N = 4/drug) were surgically instrumented with EEG/EMG electrodes. The rats were injected i.p. with zolpidem, an α1GABAAR-preferring compound, or L-838,417, which has selective efficacy for α2/3/5 subunit-containing GABAARs (i.e., α1GABAAR-sparing compound), in comparison with the non-selective benzodiazepine, triazolam. RESULTS: All ligands evaluated induced changes in sleep-wake states during the active phase consistent with an increase in slow-wave sleep (SWS). The degree of SWS increase appeared to be related to the magnitude of delta power band changes induced by the ligands, with the strongest effects engendered by the α1GABAAR-preferring drug zolpidem and the weakest effects by the α1GABAAR-sparing compound, L-838,417. Consistent with other research, a selective increase in beta band power was observed with L-838,417, which may be associated with α2GABAAR-mediated anxiolysis. CONCLUSIONS: Overall, these findings support the establishment of pharmaco-EEG "signatures" for identifying subtype-selective GABAA modulators in vivo.

Benzodiazepines Reduce Blood Pressure in Short Term: A Systematic Review and Meta-analysis.

PURPOSE OF REVIEW: Benzodiazepines, due to their anxiolytic properties, are prescribed to reduce anxiety and insomnia. They might have hypotensive effect via potentiation of the inhibitory effect of gamma-amino butyric acid (GABA) in the central nervous system and vasodilatory properties. However, studies comparing the effect of benzodiazepines in lowering blood pressure (BP) are equivocal. This systematic review and meta-analysis was planned to assess the efficacy of benzodiazepines in reducing blood pressure in short term among hypertensive patients. RECENT FINDINGS: Various trials and retrospective analysis conducted previously have reported that benzodiazepines cause short- as well as long-term BP reduction in patients with increased anxiety with hypertension. On the other hand, several studies investigating the efficacy of benzodiazepines in patients with hypertension have reported inconclusive results. The primary question about the effect of benzodiazepines in lowering BP remains unanswered. In this meta-analysis of seven studies, benzodiazepines were found comparable to standard drugs in reducing systolic and diastolic BP in patients having hypertension. Although, the mean difference in systolic BP with benzodiazepines and placebo was statistically not significant, the difference can be considered as clinically meaningful. The current review offers preliminary evidence that benzodiazepines may have antihypertensive properties and may be used as add-on antihypertensive in a subset of patients in short term. The existing data are encouraging, but more clinical trials and mechanistic research are required to ascertain the long-term benefits.

Inhibitory and excitatory synaptic neuroadaptations in the diazepam tolerant brain.

Benzodiazepine (BZ) drugs treat seizures, anxiety, insomnia, and alcohol withdrawal by potentiating γ2 subunit containing GABA type A receptors (GABAARs). BZ clinical use is hampered by tolerance and withdrawal symptoms including heightened seizure susceptibility, panic, and sleep disturbances. Here, we investigated inhibitory GABAergic and excitatory glutamatergic plasticity in mice tolerant to benzodiazepine sedation. Repeated diazepam (DZP) treatment diminished sedative effects and decreased DZP potentiation of GABAAR synaptic currents without impacting overall synaptic inhibition. While DZP did not alter γ2-GABAAR subunit composition, there was a redistribution of extrasynaptic GABAARs to synapses, resulting in higher levels of synaptic BZ-insensitive α4-containing GABAARs and a concomitant reduction in tonic inhibition. Conversely, excitatory glutamatergic synaptic transmission was increased, and NMDAR subunits were upregulated at synaptic and total protein levels. Quantitative proteomics further revealed cortex neuroadaptations of key pro-excitatory mediators and synaptic plasticity pathways highlighted by Ca2+/calmodulin-dependent protein kinase II (CAMKII), MAPK, and PKC signaling. Thus, reduced inhibitory GABAergic tone and elevated glutamatergic neurotransmission contribute to disrupted excitation/inhibition balance and reduced BZ therapeutic power with benzodiazepine tolerance.

Electrophysiological Assessment of Newly Synthesized 2,3-Benzodiazepine Derivatives for Inhibiting the AMPA Receptor Channel.

Three major subtypes of ionotropic receptors regulate glutamatergic synaptic transmission, one of which is α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptors (AMPARs). They are tetrameric, cation-permeable ionotropic glutamate receptors found across the brain. Abnormalities in AMPA receptor trafficking and synaptic assembly are linked to cognitive decline and neurological diseases such as Alzheimer's, Parkinson's, and Huntington's. The present study will investigate the effects of four novel 2,3-benzodiazepine derivatives on AMPA receptor subunits by comparing their effects on synaptic responses, desensitization, and deactivation rate in human embryonic kidney cells (HEK293T) recombinant AMPAR subunits using whole-cell patch-clamp electrophysiology. All four 2,3-BDZ compounds showed inhibitory activity against all the homomeric and heteromeric subunits tested. While the desensitization and deactivation rates in 2,3-BDZ-1 and 2,3-BDZ-2 decreased and increased, respectively, in the other two compounds (i.e., 2,3-BDZ-3 and 2,3-BDZ-4), there was no change in the desensitization or deactivation rates. These results contribute to a better understanding of AMPARs by identifying potential 2,3-BDZ drugs that demonstrate inhibitory effects on the AMPAR subunits.