Gonadotropin-releasing hormone agonist prevents l-arginine induced immune dysfunction independent of gonadal steroids: Relates with a decline in elevated thymus and brain nitric oxide levels.

The present study was carried out to find out the effect of leuprolide, a gonadotropin-releasing hormone (GnRH) receptor agonist, on l-arginine induced immunosuppression, and relates with brain and thymus levels of nitric oxide (NO). Further, the effect of leuprolide was studied in sham operated, ovariectomized and castrated mice to understand the role of sex steroids in l-arginine induced immunosuppression. Treatment with l-arginine (250, 500, 1000 mg/kg/i.

Immunohistochemical evidence for the involvement of gonadotropin releasing hormone in neuroleptic and cataleptic effects of haloperidol in mice.

Blockade of dopamine D2 receptor by haloperidol is attributed for neuroleptic and cataleptic effects; and also for the release of gonadotropin releasing hormone (GnRH) from the hypothalamus. GnRH agonist is reported to exhibit similar behavioural effects as that of haloperidol, and pre-treatment with GnRH antagonist is shown to attenuate the effects of haloperidol, suggesting a possibility that GnRH might mediate the effects of haloperidol. To substantiate such possibility, the influence of haloperidol on GnRH immunoreactivity (GnRH-ir) in the brain was studied in vehicle/antide pre-treated mice by peroxidase-antiperoxidase method.

A possible role of endogenous central corticotrophin releasing factor in lipopolysaccharide induced thymic involution and cell apoptosis: effect of peripheral injection of corticotrophin releasing factor.

The aim of the study was to investigate the role of endogenous peripheral and central corticotrophin-releasing factor (CRF) following lipopolysaccharide (LPS) challenge on thymic involution and apoptosis. Administration of LPS (100 μg/mouse, ip) led to thymic involution, to a decrease of CD4+CD8+ thymocyte subset, and to fragmentation of thymic DNA. Pretreatment of LPS challenged mice with intracerebroventricular α-helical CRF (a CRF antagonist) attenuated the effect of LPS however, intraventricular administered α-helical CRF failed to affect LPS response on thymus.

Behavioral in-effectiveness of high frequency electromagnetic field in mice.

The present investigation was carried out with an objective to study the influence of high frequency electromagnetic field (HF-EMF) on anxiety, obsessive compulsive disorder (OCD) and depression-like behavior. For exposure to HF-EMF, non-magnetic material was used to fabricate the housing. Mice were exposed to HF-EMF (2.

Paracetamol potentiates the antidepressant-like and anticompulsive-like effects of fluoxetine.

Recent studies suggest the possible involvement of serotonergic and endocannabinoid systems in analgesic, anxiolytic, and anticonvulsant-like actions of paracetamol. Considering the fact that these systems play intricate roles in affective disorders, we investigated the effects of paracetamol in depression-like and compulsion-like behavior. Swiss mice (20-22 g) were subjected to forced swim, tail suspension, or marble-burying tests after an injection of paracetamol either alone or in the presence of AM251 (a CB1 antagonist), fenclonine (pCPA: a 5-HT synthesis inhibitor), AM404 (anandamide uptake inhibitor) or fluoxetine.

Gonadotropin-releasing hormone agonist selectively augments thymopoiesis and prevents cell apoptosis in LPS induced thymic atrophy model independent of gonadal steroids.

Lipopolysaccharide (LPS) causes acute thymic atrophy, a phenomenon that has been linked to immune dysfunction and poor survival during sepsis. The systemic response to LPS involves a rise in glucocorticoids and proinflammatory cytokines which contribute greatly to thymic involution and apoptosis. Gonadotropin-releasing hormone (GnRH) analog exerts thymopoietic regulatory effects and possesses immunostimulant properties.

Experimental evidence for involvement of nitric oxide in low frequency magnetic field induced obsessive compulsive disorder-like behavior.

It is well documented that extremely low frequency magnetic field (ELF MF) produced effects on the function of nervous system in humans and laboratory animals. Dopaminergic and serotonergic pathways have been implicated in obsessive compulsive disorder (OCD). Recently involvement of nitric oxide (NO) in OCD-like behavior is suggested.

Involvement of NMDA receptor in low-frequency magnetic field-induced anxiety in mice.

It had been reported that exposure to extremely low-frequency magnetic field (ELFMF) induces anxiety in human and rodents. Anxiety mediates via the activation of N-methyl-d-aspartate (NMDA) receptor, whereas activation of γ-aminobutyric acid (GABA) receptor attenuates the same. Hence, the present study was carried out to understand the contribution of NMDA and/or GABA receptors modulation in ELFMF-induced anxiety for which Swiss albino mice were exposed to ELFMF (50 Hz, 10 G) by subjecting them to Helmholtz coils.

A possible participation of transient receptor potential vanilloid type 1 channels in the antidepressant effect of fluoxetine.

The present study investigated the influence of transient receptor vanilloid type 1 (TRPV1) channel agonist (capsaicin) and antagonist (capsazepine) either alone or in combination with traditional antidepressant drug, fluoxetine; or a serotonin hydroxylase inhibitor, para-chlorophenylalanine; or a glutamate N-methyl-D-aspartate (NMDA) receptor agonist, NMDA on the forced swim test and tail suspension test using male Swiss mice. Results revealed that intracerebroventricular injections of capsaicin (200 and 300 μg/mouse) and capsazepine (100 and 200 μg/mouse) reduced the immobility time, exhibiting antidepressant-like activity that was comparable to the effects of fluoxetine (2.5-10 μg/mouse) in both the tests.

Involvement of transient receptor potential vanilloid type 1 channels in the pro-convulsant effect of anandamide in pentylenetetrazole-induced seizures.

Anandamide, an endogenous agonist of CB(1) receptors, also activates TRPV1 but at a higher concentration. Studies demonstrate the anticonvulsant activity of anandamide via CB(1) receptors, while its action through TRPV1 is still ambiguous. Thus, the present study investigated the influence of anandamide on pentylenetetrazole-induced seizures in mice pretreated with TRPV1 or CB(1) receptor antagonists.

Endocannabinoid analogues exacerbate marble-burying behavior in mice via TRPV1 receptor.

Activation of cannabinoid CB(1) receptor is shown to inhibit marble-burying behavior (MBB), a behavioral model for assessing obsessive-compulsive disorder (OCD). Anandamide, an endogenous agonist at CB(1) receptor also activates the transient receptor potential vanilloid type 1 (TRPV1) channels but at a higher concentration. Furthermore, anandamide-mediated TRPV1 effects are opposite to that of the CB(1) receptor.

Influence of sigma-1 receptor modulators on ethanol-induced conditioned place preference in the extinction-reinstatement model.

Sigma-1 receptor agonists are reported to augment and antagonists block the rewarding effects of drugs of abuse. However, their effect on reinstatement of ethanol-induced conditioned place preference (CPP) has not yet been explored. Therefore, we investigated the ability of 2-(4-morpholino)ethyl-1-phenylcyclohexane-1-carboxylate (PRE-084), a sigma-1 receptor agonist, and N-[2-(3,4-dichlorophenyl)ethyl]-N-methyl-2-(dimethylamino) ethylamine dihydrobromide (BD-1047), a sigma-1 receptor antagonist, on the acquisition, expression, and reinstatement of ethanol-induced CPP using adult male Swiss mice.

Transient receptor potential vanilloid 1 channels modulate the anxiolytic effect of diazepam.

The present study investigated the interaction between the vanilloid and GABAergic systems on anxiety. Swiss mice were subjected to social interaction test, an animal model for assessing anxiety-related behavior, after intracerebroventricular administration of capsaicin, (TRPV1 agonist) or capsazepine, (TRPV1 antagonist) either alone or in combination with traditional anxiolytic drug, diazepam. Results showed that capsaicin (1, 10, and 100 μg/mouse) decreased the interaction time exhibiting an anxiogenic-like response, while capsazepine (10, and 100 μg/mouse) produced anxiolytic-like response similar to that of diazepam (0.

Involvement of endocannabinoids in antidepressant and anti-compulsive effect of fluoxetine in mice.

Endocannabinoid analogues exhibit antidepressant and anti-compulsive like effects similar to that of serotonin selective reuptake inhibitors (SSRIs) indicating a parallelism between the effects of serotonin and endocannabinoids. Therefore, the present study was designed to investigate the role of endocannabinoids in the antidepressant and anti-compulsive like effect of fluoxetine using mice model of forced swim test (FST) and marble-burying behavior (MBB). The results revealed that intracerebroventricular injections of endocannabinoid analogues, anandamide, a CB(1) agonist (AEA: 1-20 μg/mouse); AM404, an anandamide transport inhibitor (0.

Inhibitory influence of mecamylamine on the development and the expression of ethanol-induced locomotor sensitization in mice.

Several evidences have indicated the involvement of neuronal nicotinic acetylcholine receptors (nAChR) in behavioral effects of drugs of abuse, including ethanol. nAChRs are implicated in ethanol-induced behaviors as well as neurochemical responses to ethanol. Recently, it is demonstrated that mecamylamine, a nAChR antagonist blocks cocaine-, d-amphetamine-, ephedrine-, nicotine-, and methylphenidate-induced psychomotor sensitization.

Inhibitory influence of mecamylamine on ethanol withdrawal-induced symptoms in C57BL/6J mice.

Several reports show the involvement of neuronal nicotinic acetylcholine receptors (nAChRs) in the behavioral effects of ethanol, including ethanol drinking and relapse. Therefore, this study evaluated the effects of mecamylamine, a nAChR antagonist, on ethanol withdrawal signs. Ethanol dependence was induced in C57BL/6J mice by ethanol liquid diet administration.

Beneficial effects of L-arginine against diabetes-induced oxidative stress in gastrointestinal tissues in rats.

Oxidative stress occurs in diabetic patients and experimental models of diabetes. The ability of L-arginine to ameliorate oxidative stress after treatment with alloxan was investigated in rats. Adult male rats were injected intraperitoneally with multiple doses of alloxan to produce experimental oxidative stress characteristic of diabetes mellitus.

Endocannabinoids mediate anxiolytic-like effect of acetaminophen via CB1 receptors.

Acetaminophen (Paracetamol), a most commonly used antipyretic/analgesic agent, is metabolized to AM404 (N-arachidonoylphenolamine) that inhibits uptake and degradation of anandamide which is reported to mediate the analgesic action of acetaminophen via CB1 receptor. AM404 and anandamide are also reported to produce anxiolytic-like behavior. In view of the implication of endocannabinoids in the effect of acetaminophen, we contemplated that acetaminophen may have anxiolytic-like effect.

The 5-HT3 receptor antagonist, ondansetron, blocks the development and expression of ethanol-induced locomotor sensitization in mice.

Manipulation of the serotonergic system has been shown to alter ethanol sensitization. Ondansetron is a 5-HT3 receptor antagonist, reported to attenuate cocaine and methamphetamine-induced behavioral sensitization, but no reports are available on its role in ethanol-induced behavioral sensitization. Therefore, an attempt has been made to assess this issue by using an earlier used animal model of ethanol-induced locomotor sensitization.

Effects of central administration of gonadotropin-releasing hormone agonists and antagonist on elevated plus-maze and social interaction behavior in rats.

The correlation between neuronal mechanism of anxiety and neuroanatomic expression/neuromodulatory role of gonadotropin-releasing hormone (GnRH), points to a role of GnRH in the modulation of anxiety. Therefore, we investigated the influence of GnRH agonists and antagonist on the anxiety-like behavior of rats in the elevated plus-maze and social interaction tests. GnRH agonists, leuprolide [100 or 200 ng/rat, intracerebroventricularly (i.

Quercetin pretreatment increases the bioavailability of pioglitazone in rats: involvement of CYP3A inhibition.

Herbal antidiabetic preparations are often used as an add-on therapy in diabetes and such herbal preparations often contains quercetin that can inhibit cytochrome P450 (CYP) 3A4. This enzyme is responsible for metabolizing pioglitazone, a commonly used antidiabetic agent. Hence, it was speculated that quercetin may influence the bioavailability of pioglitazone, which could be particularly crucial, as any increment in its plasma levels may raise safety concerns.

Synthesis and anti-inflammatory activity of alkyl/arylidene-2-aminobenzothiazoles and 1-benzothiazol-2-yl-3-chloro-4-substituted-azetidin-2-ones.

Ten new derivatives of 1-benzothiazol-2-yl-3-chloro-4-substituted-azetidin-2-ones (3a-j) were synthesized using various Schiff bases (alkyl/arylidene-2-aminobenzothiazoles; 2a-j), which in turn were prepared starting from 2-aminobenzothiazole (1). All the synthesised compounds were characterised by elemental analyses and spectral (IR, 1H-NMR, 13C-NMR and EI-MS) data. The title compounds 2a-j and 3a-j were screened in vivo using carrageenan-induced rat paw edema model.