Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Benzodiazepines”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed1977

Double-blind cross-over clinical comparison of two 2'-chloro benzodiazepines: 7-chloro-5-(2-chlorophenyl)-1,3-dihydro-2H-1,4-benzodiazepin-2-one (chlordesmethyldiazepam) versus 7-chloro-5-(o-chlorophenyl)-1,3-dihydro-3-hydroxy-2H-1,4-benzodiazepin-2-one (lorazepam) in neurotic anxiety.

A group of 20 female neurotic inpatients has been treated with 7-chloro-5-(2-chlorophenyl)-1,3-dihydro-2H-1,4-benzodiazepin-2-one-(chlordesmethyldiazepan)- 7-chloro-5(o-chlorophenyl)-1,3-dihydro-3-hydroxy-2H-1,4-benzodiazepin-2-one (lorazepam) according to a double-blind cross-over design. For each drug clinical evaluations were performed by means of Hamilton's rating scale for anxiety states and of Overall and Gorham's brief psychiatric rating scale, at the beginning, after the first week and at the end of the two-week period of treatment, in opposite sequence. A statistically greater efficacy of chlordesmethyldiazepam in comparison to lorazepam was observed. Results are discussed with regard to benzodiazepine structure-activity relationships.

Adult↗
PubMed1992

1,5-Benzodiazepines. X. Dialkylamino substituted 1,5-benzodiazepine and [1,2,4]triazolo [4,3-a][1,5] benzodiazepine derivatives with inhibitory activity on PAF-induced platelet aggregation.

Novel 4-(dialkylamino) substituted (4, 5 c, 8) and 2,4-bis(dialkylamino) substituted (6) 1,5-benzodiazepine derivatives were synthesized. Both these new compounds and the substituted 4H-[1,2,4]triazolo[4,3-a][1,5]benzodiazepine-5-amines 2 a-h, recently described by us, were tested in vitro for their inhibitory activity on the PAF-induced aggregation of human platelets. Actually, bicyclic compounds 4 d, 5 c and tricyclic compounds 2 g, h showed a significant activity: in all them the dialkylamino substituent was the 4-(ethoxycarbonyl)-1-piperazinyl group. On the contrary, compounds 4 d, 5 c, 2 g,h showed practically no inhibitory activity when platelet aggregation was induced by ADP, A23187, or collagen.

Benzodiazepines↗
PubMedDate not supplied

Treatment of benzodiazepine overdose with flumazenil. The Flumazenil in Benzodiazepine Intoxication Multicenter Study Group.

Flumazenil, a specific benzodiazepine antagonist, was evaluated as adjunctive therapy in the management of benzodiazepine overdose. Thirteen emergency departments enrolled 326 patients in this double-blind, placebo-controlled trial; 162 patients were randomly allocated to receive flumazenil (maximum dose, 30 ml, providing 3 mg of flumazenil), and 164 were allocated to receive placebo (maximum dose, 30 ml). A successful response was the attainment of a score of 1 or 2 on the Clinical Global Impression Scale (CGIS), denoting a very much improved or much improved status, 10 minutes after the start of intravenous administration of the test drug. Among those patients whose drug screen revealed the presence of benzodiazepines, 75 (77%) of 97 patients given flumazenil and 13 (16%) of 83 given placebo attained such a response. The mean CGIS score at 10 minutes for benzodiazepine-positive patients treated with flumazenil was 1.95 versus 3.58 for those given placebo. As determined by the Neurobehavioral Assessment Scale, 61% of patients who initially responded became resedated; in these patients, the effect of flumazenil lasted a median of 90 minutes. At the investigator's discretion, patients who did not achieve a criterion response in the double-blind trial could receive open-label flumazenil, titrated as in the double-blind phase. Among the benzodiazepine-positive patients, 9 (53%) of 17 patients from the flumazenil group responded to the additional flumazenil, and 58 (81%) of patients previously given placebo responded. Safety was assessed in all 326 patients given the test drug. The most frequent adverse experiences after the administration of flumazenil were agitation (7%), vomiting (7%), abnormal crying (4%), and nausea (4%); these effects were observed with a lower frequency in the placebo group. Serious adverse experiences were reported in 4 patients; these included seizures and cardiac arrhythmias. Of the 3 patients with seizures, 2 had ingested large doses of cyclic antidepressants in addition to the benzodiazepine. The toxicology screen for 1 of the 2 showed 1900 ng/ml of amoxapine and 900 ng/ml of nortriptyline; the toxicology screen for the other, who also had ventricular tachycardia, showed 1928 ng/ml of loxapine and 301 ng/ml of amoxapine. The results of this study confirm published reports of the efficacy of flumazenil in reversing benzodiazepine-induced sedation in patients with benzodiazepine overdose. This was accomplished irrespective of the presence of coingested drugs. Flumazenil is not recommended for patients with serious cyclic antidepressant poisoning or those who use benzodiazepines therapeutically to control seizure disorders. When used as recommended, however, flumazenil has been shown to have an acceptable safety level.

Adolescent↗
PubMedDate not supplied

Mapping of benzodiazepine-like immunoreactivity in the rat brain as revealed by a monoclonal antibody to benzodiazepines.

A monoclonal antibody against benzodiazepines (21-7F9) was used to study the distribution of benzodiazepine-like immunoreactivity in the rat brain. Immunodensitometry in combination with image analysis were used for quantification. The results showed a ubiquitous distribution of benzodiazepine-like immunoreactivity throughout the brain. Very high levels of benzodiazepine-like immunoreactivity were found in the Purkinje cell layer of the cerebellum, in the primary olfactory cortex, in the stratum pyramidale of the hippocampus and in the mitral cell layer of the olfactory bulb. High densities of benzodiazepine-like immunoreactivity were found in the granule cell layer of the cerebellum, the pyramidal cell layer of the olfactory tubercle, the granule layer of the dentate gyrus, the arcuate nucleus of the hypothalamus, the mammillary bodies, the interstitial nucleus of Cajal and superficial grey layer of superior colliculus. The substantia nigra pars compacta, the islands of Calleja and layers II, III, V and VI of the cerebral cortex had moderate levels of benzodiazepine-like immunoreactivity. Lower densities were found in the internal granular layer and the external plexiform layer of the olfactory bulb, in the molecular layer of the dentate gyrus, in layers I and IV of the cerebral cortex, in the nucleus caudate-putamen and most of the thalamic nuclei. The lowest density of immunoreactivity was found in the globus pallidus, and the strata radiatum, oriens and lacunosum-moleculare of the hippocampus. The distribution of endogenous benzodiazepine-like immunoreactivity was compared with the distribution of the GABA/benzodiazepine receptor by using both immunocytochemistry and receptor autoradiography. Our studies have shown a clear mismatch between the localization of the benzodiazepine-like immunoreactivity and the GABA/benzodiazepine receptors.

Animals↗
PubMed1990

Effects of benzodiazepines on passive avoidance response and latent learning in mice: relationship to benzodiazepine receptors and the cholinergic neuronal system.

The effects of benzodiazepines on learning and memory were investigated, using passive avoidance and latent learning tasks, with particular attention being paid to the possible involvement of benzodiazepine receptors and the cholinergic neuronal system. Benzodiazepines such as diazepam, nitrazepam and chlordiazepoxide (CDP) impaired the passive avoidance response when administered before training, but not when administered immediately after training or before the retention test. CDP also impaired latent learning in the water finding task. State-dependent learning was not observed with CDP at the dose used. A benzodiazepine inverse agonist, Ro 15-4513, and a benzodiazepine antagonist, Ro 15-1788, completely and partially reversed, respectively, the disruptive effects of CDP on learning and memory at the doses which did not enhance learning and memory. The disruptive effects of CDP on learning and memory were partially antagonized by a choline esterase inhibitor, physostigmine, and by a blocker for muscarinic acetylcholine receptors, scopolamine, at the doses which increase acetylcholine release. These results suggest that benzodiazepines induce disruptive effects on learning and memory through benzodiazepine receptors, and that benzodiazepine-induced impairment of learning and memory is, at least in part, the result of the dysfunction of the cholinergic neuronal system.

Animals↗
PubMed1990

Benzodiazepine dependency discontinuation: focus on the chemical dependency detoxification setting and benzodiazepine-polydrug abuse.

Benzodiazepines are commonly encountered in both psychiatric and chemical dependency treatment settings. However, in the chemical dependency setting, benzodiazepines are most frequently used as secondary drugs of abuse, and are most often found within a polydrug use pattern. Benzodiazepine use by the drug-abusing population consists of the combined use of benzodiazepines with other psychoactive drugs. They are used to medicate cocaine toxicity, as a secondary or tertiary drug to boost the effects of alcohol or heroin, and by those who have developed tolerance and dependence to sedative-hypnotic drugs. The presence of an anxiety disorder, a family history of addiction, or benzodiazepine polydrug use will significantly affect the type of withdrawal a patient will experience and its treatment course. Medical procedures accepted for benzodiazepine discontinuation include (1) graded reduction; (2) substitution of a long-acting benzodiazepine; and (3) phenobarbital substitution.

Anti-Anxiety Agents↗
PubMed1978

Benzodiazepine receptor binding: the interactions of some non-benzodiazepine drugs with specific [3H] diazepam binding to rat brain synaptosomal membranes.

The interaction of several non-benzodiazepine drugs with [3H] diazepam binding to benzodiazepine receptors in rat brain synaptosomal membranes was investigated. Baclofen, benzoctamine, hydroxyzine, chlorpromazine, haloperidol, imipramine, and amitriptyline displace specific [3H] diazepam binding, but the concentrations needed are too high to explain pharmacological effects of these drugs by an interaction with benzodiazepine receptors. The most potent non-benzodiazepine drug for inhibiting specific [3H] diazepam binding was methaqualone (IC50 value of 150 micrometer). It is suggested that interactions with benzodiazepine receptors may account for the anxiolytic and anticonvulsive side effects of this drug. The analeptic drug pentylenetetrazole interacts with benzodiazepine receptor binding with an IC50 value of about 1 mM, which is possibly too high to explain its convulsive properties by an antagonism at the benzodiazepine receptor.

Animals↗
PubMedDate not supplied

[Plea for benzodiazepines or is there a future for benzodiazepines in psychiatry?].

Thirty years ago chlordiazepoxide was used in psychiatry for the first time. Benzodiazepines, a therapeutic class with a large spectrum of activities, are now used regularly by 5 to 15% of adults. In France 15% of prescriptions include at least 1 benzodiazepine and 5 compounds of this class appear among the 30 most frequently prescribed of state reimbursed medications. In a developing country like Tunisia sales of psychotropic drugs increased by 84% between 1984 and 1987, benzodiazepines representing half of the prescriptions. Criticisms were voiced as early as in the years 1970. Ralph Nader himself led a campaign against those drugs used in suicidal attempts, provoking car accidents and industrial injuries, memory deficits and dependence. Later, several side effects were pin-pointed: amnesia, which has been used with criminal intent in a few dramatic cases; in fact it should be differentiated from the cognitive troubles resulting from anxiety itself; tolerance: for instance in drug addicts using high doses; it concerns only some effects of the drug; dependence: which remains rare when contrasted with the large consumption of benzodiazepines; withdrawal reaction should be differentiated from teh relapse of anxiety once the drug has been discontinued. In the public opinion one is supposed to bear any pain--and never complain--when it is psychic and not somatic. Benzodiazepines that alleviate psychic pain were considered with spite and then grudge, to use the terminology of erotomania. Actually, benzodiazepine treatment should be a part of a larger therapeutic program taking into account the characteristics of each individual patient.(ABSTRACT TRUNCATED AT 250 WORDS)

Benzodiazepines↗
PubMed1990

The involvement of the benzodiazepine receptor in hepatic encephalopathy: evidence for the presence of a benzodiazepine receptor ligand.

The involvement of GABAergic systems in the pathogenesis of HE was supported by electrophysiologic studies of single Purkinje neurons from rabbits with HE which demonstrated the hypersensitivity of these neurons to depression by GABA and BZ receptor agonists. In contrast, these neurons were excited by BZ receptor antagonists. At concentrations which had no effect on neuronal activity, BZ receptor antagonists also reversed the hypersensitivity of HE neurons to depression by muscimol. This combination of neuronal responses is consistent with an increase in the concentration or availability of a ligand for the BZ receptor with agonist properties in the brains of rabbits with HE. Subsequent neurochemical studies support these electrophysiologic observations. Autoradiographic techniques indicated the presence of a reversible inhibitor of [3H]Ro 15-1788 and [3H]flunitrazepam binding to the cerebral and cerebellar cortices of rabbits with HE. The ability of this substance to inhibit [3H]flunitrazepam binding to HE rabbit brain sections was further enhanced in the presence of NaCl and GABA. The autoradiographic studies suggested that the density and affinity of the components of the GABA-BZ receptor complex are unaltered in this animal model of HE. This inference is fully supported by the subsequent studies of radioligand binding to well-washed membrane preparations. Finally, extracts of HE rabbit brains yielded a family of substances with the properties of BZ receptor agonists. These substances may include, but are not limited to, diazepam, oxazepam and desmethyldiazepam, but do not include substances commonly elevated in the plasma and CSF of patients with HE4. The positive identification of these substances awaits confirmation by mass-spectroscopic analysis. However, the precedent for the presence of a family of benzodiazepines in animals that were not administered these drugs has been set. The origin of these substances is a matter of ongoing research. Several studies have shown the presence of benzodiazepines in plant and animal materials. It is possible that these "endogenous" benzodiazepines are the result of contamination of the food chain. A normally functioning liver would capture and metabolize these compounds after their absorption from the gut. This function of the liver would be impaired in liver failure, thus allowing sufficient levels of BZ receptor agonists to accumulate in the CNS, contributing to the pathogenesis of HE. However, studies by DeBlas and coworkers have reported that 1,4 benzodiazepines are present in human brains preserved prior to the commercial use of these compounds. Further, they have found benzodiazepines in cell lines cultured without potential exogenous sources of benzodiazepines.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1990

Chronic benzodiazepine antagonist treatment and its withdrawal upregulates components of GABA-benzodiazepine receptor ionophore complex in cerebral cortex of rat.

Effect of chronic administration of benzodiazepine (BZ) receptor antagonist Ro 15-1788 (flumazenil) (4 mg/kg once daily for 14 days) treatment and its withdrawal on locomotor activity, body temperature, and the binding pattern of receptor ligands that bind to GABA-BZ receptor ionophore complex in different regions of the brain of the rat was studied. Ro 15-1788 (x 14 d) increased the specific binding of [3H]ethyl-8-fluoro-5-6-dihydro-5-methyl-6-oxo-4H- imidazo[1,5 alpha][1,4]benzodiazepine-3-carboxylate [( 3H]Ro 15-1788), [3H]ethyl-8-azido-5-6-dihydro-5-methyl-6-oxo-4H- imidazo[1,5 alpha][1,4]benzodiazepine-3-carboxylate [( 3H]Ro 15-4513), [3H]flunitrazepam, and [35S]t-butylbicyclophosphorothionate [( 35S]TBPS) in cerebral cortex, and this increase in binding remained upregulated during the drug withdrawal at 24 h. The binding of [3H]Ro 15-1788 was also found significantly increased in the hippocampus, but not in cerebellum and striatum. The chronic Ro 15-1788 treatment did not alter the specific binding of [3H]GABA. Rosenthal analysis of the saturation isotherms indicated that the observed upregulation in the binding pattern of [3H]Ro 15-1788 and [3H]Ro 15-4513 in the cerebral cortex was due to an increase in the binding capacity (Bmax). The receptor affinity (Kd) was not changed. The withdrawal of Ro 15-1788 following its chronic administration also enhanced locomotor activity. However, no apparent change in body temperature was observed either due to chronic treatment or withdrawal. These data indicate that chronic Ro 15-1788 treatment and its withdrawal may produce an upregulation of subunits which bind the positive (benzodiazepines), negative (inverse agonist), and neutral (antagonist) ligands of benzodiazepine receptor.(ABSTRACT TRUNCATED AT 250 WORDS)

Affinity Labels↗
PubMed1979

A synthetic non-benzodiazepine ligand for benzodiazepine receptors: a probe for investigating neuronal substrates of anxiety.

CL 218,872 is the first non-benzodiazepine to selectively displace brain specific 3H-diazepam binding with a potency comparable to that of the benzodiazepines. Like the benzodiazepines, CL 218,872 increased punished responding in a conflict situation and protected against the convulsions induced by pentylenetetrazole. These three pharmacological properties are highly predictive of anxiolytic activity. Unlike the benzodiazepines, however, CL 218,872 was relatively inactive in tests designed to measure effects on neuronal systems which utilize GABA, glycine and serotonin as transmitters. Furthmore, CL 218,872 was relatively free of the ataxic and depressant side effects commonly associated with the benzodiazepines. Because of this high degree of selectivity, CL 218,872 may represent a new probe for investigating neuronal substrates of anxiety.

Animals↗
PubMed1990

Addiction potential of benzodiazepines and non-benzodiazepine anxiolytics.

This paper reviews the addiction potential of all benzodiazepines currently available in the U.S.A. as well as several non-benzodiazepine anxiolytic drugs. Addiction potential was assessed by separately considering the potential for these drugs to produce three different phenomena of addiction; namely, physical dependence, psychological dependence and deleterious consequences. This review focuses on human studies conducted with research volunteers outside the therapeutic context and also on clinical studies conducted with patients receiving treatment in the therapeutic context. It is concluded that benzodiazepines have a reduced addiction potential in comparison to the predecessor barbiturates. Conclusions regarding the relative addiction potential of several non-benzodiazepine anxiolytics are difficult due to a paucity of data; however limited evidence suggests a reduced addiction potential for several of these compounds. Within the benzodiazepine class, qualitative differences in addiction potential between individual drugs are not well established.

Anti-Anxiety Agents↗
PubMed1992

Biotinylated 1012-S conjugate as a probe ligand for benzodiazepine receptors: characterization of receptor binding sites and receptor assay for benzodiazepine drugs.

A nonisotopic receptor assay using the biotin-1012-S conjugate was developed and the usefulness of this conjugate as a probe ligand for the benzodiazepine receptor was evaluated. The conjugate was incubated in a receptor suspension, and then the concentration of free conjugate in the supernatant was determined nonisotopically with a solid-phase avidin-biotin binding assay. Studies on the ligand saturation with the conjugate demonstrated that the conjugate has very high affinity and specificity for the receptors and the biotin labeling does not decrease the affinity of 1012-S. This assay method was applied to the characterization of binding sites of benzodiazepine receptors in cow brain. Competition interactions between the conjugate and benzodiazepine drugs gave well-defined dose-response curves. These results confirm the possibility that this conjugate could serve as a probe for the study of receptor-ligand interactions and provide the basis of a new nonisotopic receptor assay for benzodiazepine drugs.

Animals↗
PubMed1990

Nitrendipine decreases benzodiazepine withdrawal seizures but not the development of benzodiazepine tolerance or withdrawal signs.

1. The effects of the calcium channel blocking agent, nitrendipine, were studied on seizures in mice produced during withdrawal from chronic benzodiazepine treatment and on the development of tolerance to benzodiazepines. 2. Nitrendipine produced a dose-dependent decrease in seizure incidence, when seizures were produced by the partial inverse agonist FG7142 during withdrawal from seven days treatment with flurazepam. 3. Nitrendipine did not raise the seizure thresholds in naïve mice to the full inverse agonist methyl-6,7-dimethoxy-4-ethyl-beta-carboline-3-carboxylate (DMCM), or to the gamma-aminobutyric acid (GABA) antagonist, bicuculline. 4. When given concurrently with flurazepam for seven days, nitrendipine did not affect the incidence of seizures during flurazepam withdrawal. 5. When given concurrently with the benzodiazepines, nitrendipine did not prevent the development of tolerance to midazolam general anaesthesia or tolerance to the ataxic actions of flurazepam or midazolam. 6. Chronic treatment with flurazepam for seven days did not affect the Kd or Bmax of [3H]-nimodipine binding in mouse whole brain or cerebral cortex. 7. These results with benzodiazepines are partially in contrast with those for ethanol, where nitrendipine not only decreased ethanol withdrawal seizures when given acutely, but also prevented the development of tolerance and withdrawal signs when given concurrently with ethanol. However, they do confirm the selectivity of nitrendipine for withdrawal-induced seizures.

Animals↗
PubMed1991

Peripheral-type benzodiazepine receptors: a second site of action for benzodiazepines.

Benzodiazepines are among the most widely used therapeutic drugs because of their sedative and anxiolytic effects mediated through modulation of GABAA receptors. Another recognition site for these drugs, termed the peripheral-type (or mitochondrial) benzodiazepine receptor, is much more prevalent throughout the body for which a physiologic and pharmacologic role has just been found. This drug receptor plays a central role in the regulation of steroidogenesis by mediating the rate-limiting step in this biosynthetic pathway, which is transport of cholesterol to inner mitochondrial membranes. Although once considered by many to be an insignificant drug-binding site because a specific function remained elusive for many years, peripheral-type benzodiazepine receptors are now viewed with renewed interest because certain benzodiazepines such as diazepam may exert secondary effects on steroid production under appropriate physiologic conditions. Elucidation of this receptorial role should initiate new studies to examine in more detail the pharmacologic profile of drugs that bind to these sites and provides a novel target for the treatment of certain types of endocrine disorders.

Animals↗
PubMed1990

Addictive behaviors and benzodiazepines: 2. Are there differences between benzodiazepines in potential for physical dependence and abuse liability?

This paper examines data on the question of possible differences between benzodiazepines in abuse liability and potential for causing physical dependence. The data on potential for causing physical dependence indicates that all benzodiazepines cause physical dependence and there is little evidence for substantial differences between them in this respect. The evidence for substantive differences between benzodiazepines with respect to abuse liability is reviewed: problems with methodology and with definitions make problematic the assertion of some authors that there are clinically meaningful differences in abuse liability. There is general agreement that all benzodiazepines have at least some abuse liability.

Anti-Anxiety Agents↗
PubMed1977

[Study of 1,5-benzodiazepines. II. Synthesis of 2,4-di-(N-alkyl,N-phenyl)amino-3H-1,5-benzodiazepine].

Following the procedure we described for synthesizing analogous compounds in Note I (7), reaction of N,N-dialkyl or (N-alkyl,N-phenyl)ethoxycarbonylacetamides with 4-chloro-1,2-phenylendiamine, in the presence of phosphorus oxychloride, afforded 2,3-dihydro-2-oxo-4-dialkyl (N-alkyl,N-phenyl)amino-chloro-1H-1,5-benzodiazepines. When a large amount of phosphorus oxychloride was employed in the reaction, the formation of 2,4-di-(N-alkyl,N-phenyl)amino-3H-1,5-benzodiazepines was achieved, starting from suitable o-phenylendiamines and (N-alkyl,N-phenyl)ethoxycarbonylacetamides. Pharmacological tests were carried out on some compounds described in the present paper and on others reported in the preceding Note (7); in this connection 4-amino-1,5-benzodiazepine derivatives showed weak CNS depressing activity in addition, in some cases, to clear, although moderate, anticonvulsant activity, whereas 2,4-diamino-1,5-benzodiazepine derivatives were practically without effect.

Animals↗
PubMedDate not supplied

Effects of the benzodiazepine receptor agonist midazolam and antagonist flumazenil on 5-hydroxytryptamine release from guinea-pig intestine in vitro. Indirect support for a "natural" benzodiazepine-like substance in the intestine.

Isolated segments of the guinea-pig small intestine and the guinea-pig stomach were vascularly perfused and the release of 5-hydroxytryptamine (5-HT) and 5-hydroxyindoleacetic acid into the portal venous effluent determined by high pressure liquid chromatography with electrochemical detection. Test substances were applied intraarterially. The benzodiazepine receptor agonist, midazolam, concentration-dependently increased (by 58%, at 1 nmol/l) and decreased (by 32%, at 100 nmol/l) the release of 5-HT from small intestine preparations. Both effects were blocked by the benzodiazepine receptor antagonist flumazenil (10 nmol/l) The stimulatory effect of midazolam was also abolished in the presence of tetrodotoxin (1 mumol/l) or scopolamine (100 nmol/l). In the absence of tetrodotoxin, flumazenil (10 nmol/l) alone decreased the release of 5-HT from the small intestine by 41%, but it increased the release of 5-HT by 50% in the presence of tetrodotoxin. Both effects of flumazenil were abolished in the presence of bicuculline (50 mumol/l). In the absence of tetrodotoxin, flumazenil (10 nmol/l) decreased also the release of 5-HT and its metabolite from the perfused stomach by about 40%, whereas midazolam (1 nmol/l) caused an increase by about 60%. In conclusion, benzodiazepine receptors modulate the previously described intrinsic GABAergic regulation of 5-HT release from enterochromaffin cells in the guinea-pig intestine. It is suggested that an endogenous benzodiazepine-like substance of non-neuronal origin is present in the small intestine and stomach of the guinea-pig.

Animals↗