Genetic Analysis of Mu and Kappa Opioid Receptor and COMT Enzyme in Cancer Pain Tunisian Patients Under Opioid Treatment.

Background: Pain and its opioid treatments are complex measurable traits. Responses to morphine in terms of pain control is likely to be determined by many factors, including the underlying pain sensitivity of the patient, along with nature and extent of the painful process, concomitant medications, genetic and other clinical and environmental factors. This study investigated genetic polymorphisms implicated in the inter-individual pain response variability to opioid treatment in the Tunisian population.

Association of the OPRM1 and COMT genes' polymorphisms with the efficacy of morphine in Tunisian cancer patients: Impact of the high genetic heterogeneity in Tunisia?

Background: Genetic causes for inter-individual variability response to opioids are clinical difficulties for treatment efficiency. The aim of the present study was to investigate the possible association of opioid treatment outcome with single nucleotide polymorphisms (SNPs) in the mμ opioid receptor (OPRM1) and catechol-o-methyltransferase (COMT) genes, in Tunisian cancer pain patients.

Methods: We genotyped one hundred and twenty-nine cancer patients treated with different doses of morphine for 3 SNPs in OPRM1 gene (rs17174629, rs1799972 and rs1799971) and one in the COMT gene (rs4680).

Inhibition of human Kv3.1 current expressed in Xenopus oocytes by the toxic venom fraction of Androctonus australis hector.

AahG50, the toxic fraction of Androctonus australis hector venom, was studied on human Kv3.1 channels activation, stably expressed in Xenopus oocytes using the two-electrode voltage clamp technique. AahG50 reduced Kv3.

Hemitoxin, the first potassium channel toxin from the venom of the Iranian scorpion Hemiscorpius lepturus.

Hemitoxin (HTX) is a new K+ channel blocker isolated from the venom of the Iranian scorpion Hemiscorpius lepturus. It represents only 0.1% of the venom proteins, and displaces [125 I]alpha-dendrotoxin from its site on rat brain synaptosomes with an IC50 value of 16 nm.