Previous work from this laboratory has shown that the electrically evoked release of enkephalin from the guinea pig myenteric plexus is regulated by an opiate receptor-mediated, concentration-dependent mechanism. Low concentrations (nanomolar) of opioids enhance release, whereas higher concentrations (10-100 nM) inhibit release. Each opioid effect is mediated by a different guanine nucleotide-b...

The endogenous opioid system plays a significant role in the modulation of distress in many psychiatric, neurologic, and neurodevelopmental disorders. Many clinical distress symptoms show similarities to the excitatory autonomic withdrawal effects in chronic opioid-dependent animals and humans, as well as to the “quasi-morphine withdrawal syndrome” evoked in naïve rodents shortly after acute sy...

Opioids/opiates are commonly administered to alleviate pain, unload the heart, or decrease breathlessness in patients with advanced heart failure. As such, it is important to evaluate whether the myocardial opioidergic system is altered in cardiac disease. A hamster model of spontaneous hypertension was investigated before the development of hypertension (1 mo of age) and in the hypertensive st...

The opioid system influences learning and memory processes. However, neural mechanisms underlying the modulation of hippocampal activity by opioid receptors remain largely unknown. Here, we compared how mu and delta receptors operate within the mouse CA1 network, and used knock-in mice expressing functional delta opioid receptors fused to the green fluorescent protein (DOR-eGFP) to determine ho...

Background and Purpose Cannabidiol (CBD) is a non-euphorigenic component of Cannabis sativa that prevents the development paclitaxel-induced mechanical sensitivity in mouse model chemotherapy-induced peripheral neuropathy (CIPN). We recently reported CBD structural analogue KLS-13019 shows efficacy an vitro CIPN. The present study was to characterize behavioural effects compared morphine models...

Cyclic AMP (cAMP) regulates a number of cellular processes and modulates cell death induction. cAMP levels are altered upon stimulation of specific G-protein-coupled receptors inhibiting or activating adenylyl cyclases. Opioid receptor stimulation can activate inhibitory Gi-proteins which in turn block adenylyl cyclase activity reducing cAMP. Opioids such as D,L-methadone induce cell death in l...

OBJECTIVE The completion of the human genome sequence has spurred investigation of the genetic contribution to substance dependence. In this article some of the recent scientific evidence for genetic determinants of opioid and cocaine dependence is reviewed. METHOD An electronic search of the medical literature was conducted to locate published studies relevant to the genetics of opioid and c...

The ability of neuropeptide Y to potently stimulate food intake is dependent in part upon the functioning of mu and kappa opioid receptors. The combined use of selective opioid antagonists directed against mu, delta or kappa receptors and antisense probes directed against specific exons of the MOR-1, DOR-1, KOR-1 and KOR-3/ORL-1 opioid receptor genes has been successful in characterizing the pr...