Search results for "CAI"

Role of dopamine neurotransmission in the long-term effects of repeated social defeat on the conditioned rewarding effects of cocaine

2016

Numerous studies report that social defeat stress alters dopamine (DA) neurotransmission in several areas of the brain. Alterations of the mesolimbic dopaminergic pathway are believed to be responsible for the increased vulnerability to drug use observed as a result of social stress. In the present study, we evaluated the influence of DA receptors on the long-term effect of repeated social defeat (RSD) on the conditioned rewarding and reinstating effects of cocaine. For this purpose, the D1R antagonist SCH 23390 and the D1R antagonist raclopride were administered 30 min before each social defeat and a cocaine-induced CPP procedure was initiated three weeks later. The expression of the D1R a…

Decreased kynurenine pathway potentiate resilience to social defeat effect on cocaine rewa

2021

The kynurenine (KYN) pathway of tryptophan (TRP) degradation is activated by stress and inflammatory factors. It is now well established that social stress induces the activation of the immune system, with central inflammation and KYN metabolism being two of the main factors linking stress with depression. The aim of the present study was to evaluate the long-lasting changes in the KYN pathway induced by social defeat (SD) associated with the resilience or susceptibility to an increase in the conditioned rewarding effects of cocaine. Mice were exposed to repeated SD and 3 weeks later, a conditioned place preference (CPP) induced by a subthreshold dose of cocaine (1.5 mg/kg) was developed. K…

Effects of intraurethral injection of anaesthetic gel for transurethral instrumentation

2006

Autoinhibition of noradrenaline release from the rat heart as a function of the biophase concentration. Effects of exogenous alpha-adrenoceptor agoni…

1984

1. Rat isolated perfused hearts with the right sympathetic nerves intact were loaded with 3H-(-)-noradrenaline. The nerves were stimulated with trains of 180 pulses at 3 Hz and at 10 min intervals. The overflow of 3H-noradrenaline and 3H-metabolites was determined by liquid scintillation spectrometry. 2. Clonidine (IC50 17 nM), oxymetazoline (IC50 63 nM), and α-methylnoradrenaline (apparent IC50 35 nM, determined in the presence of cocaine and propranolol) decreased the stimulation-evoked overflow of 3H-noradrenaline by 26, 49, and 78%, respectively, but not methoxamine up to 100 μM (propranolol present). Oxymetazoline and α-methyl-noradrenaline did not cause desensitization of the presynap…

Cocaine-induced locomotor activity is enhanced by exogenous testosterone

2002

Anabolic-androgenic steroids are synthetic derivatives of testosterone, which are increasingly abused by adolescent populations who also abuse psychoactive substances. All these compounds lead to complex behavioral syndromes and the effects of their interactions remain unclear. The main aim of the present study was to determine the influence of testosterone on the locomotor activity-promoting effect of cocaine on male mice in an open field. In the three experiments, animals received two injections: firstly, testosterone or peanut oil, and secondly, cocaine or saline solution. In Experiments 1 and 2, testosterone (or oil) and cocaine (or saline) were injected 45 and 10 min, respectively, pri…

Pharmacological analysis of the responsiveness of guinea-pig lung parenchymal strip to dopamine

1984

Abstract Responses to dopamine were examined in the guinea-pig isolated lung parenchymal strip. Complete cumulative concentration-response curves to dopamine exhibited a biphasic pattern with a small initial contraction at concentrations below 10(-5) M followed by a dose-dependent relaxation at higher concentrations. Phentolamine (10(-5) M) completely abolished the contractile component and enhanced sensitivity and maximal relaxation to dopamine. In the presence of phentolamine, propranolol antagonized the dopamine-induced relaxation (pA2 = 8.54 +/- 0.07). In the presence of propranolol (10(-6) M), dopamine produced a dose-related contraction displaced to the right by phentolamine. Incubati…

The effect of dopamine on the overflow of endogenous noradrenaline from the perfused rabbit heart evoked by sympathetic nerve stimulation.

1978

1. The effects of dopamine and two dopamine receptor antagonists (pimozide, flupenthixol) on the release of endogenous noradrenaline evoked by electrical stimulation of the postganglionic sympathetic nerves and their influence on cardiac performance were measured in isolated perfused rabbit hearts. 2. Dopamine 0.2μM decreased noradrenaline overflow and ventricular tension development in response to nerve stimulation. 3. Dopamine 2μM increased spontaneous noradrenaline output and tension development. The noradrenaline overflow in response to nerve stimulation was greatly enhanced. This action was only partly reversed by wash out of exogenous dopamine, indicating de novo synthesis and facilit…

Epidural ropivacaine -- where are the benefits? A prospective, randomized, double-blind trial in patients with retropubic prostatectomy.

2007

Background:  In comparison with bupivacaine, ropivacaine exhibits comparable anaesthetic effects but with less motor impairment and systemic toxicity. However, the analgesic potency may differ. For example, ropivacaine during obstetric epidural analgesia provides an approximately 40% lower analgesic potency than bupivacaine. Equal visual analogue pain scores require significantly higher dosages of ropivacaine, and general statements about a favourable benefit–risk profile relative to that of bupivacaine may therefore have limited clinical impact. We addressed this topic in a male pain model by evaluating the analgesic efficacy of epidural ropivacaine 0.2% vs. bupivacaine 0.125% after retrop…

Comparison between local and regional anesthesia in arteriovenous fistula creation.

2011

Purpose Assessment of the effectiveness of Brachial Plexus Block (BPB) via axillary approach compared to regional anesthesia for arteriovenous fistula surgery in patients affected by end-stage renal disease. Methods We compared forty patients randomly divided into two groups. Group A underwent BPB procedure with 15 mL ropivacaine 1% and 10 mL of saline (0.9% NaCl) via axillary approach. Group B received local anesthesia with lidocaine 2%. The forearm blood vessels were assessed by Doppler ultrasonography before and after the intervention. Results BPB performed on Group A was associated with a considerable venous dilation and a significant decrease (48.7%, P<.05) in pulsatility index (PI)…

Effects of extended cocaine conditioning in the reinstatement of place preference.

2008

Rats allowed extended access to cocaine self-administration develop a number of symptoms of addiction, such as greater susceptibility to drug-induced relapse. Using the conditioned place preference (CPP), the number of conditioning training sessions was increased in order to augment exposure to contextual cues associated with the effects of a drug. Mice were conditioned with a steady dose of 6 or 25 mg/kg of cocaine for 4, 8, 12, 16, 20 or 40 days. Weekly sessions of extinction followed the establishment of preference, after which a priming dose of cocaine was administered to reinstate the extinguished preference. The magnitude of the place preference effect was equal in all groups, indepen…