Life sciences
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Although hyperbaric oxygen (HBO) treatment following spinal cord injury (SCI) have been studied in terms of neurological function and tissue histology, there is a limited number studies on spinal cord tissue enzyme levels. ⋯ HBO treatment was found to be beneficial following SCI in terms of biochemical parameters and functional recovery in the postoperative period.
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The aim of this present study was to investigate the changes of peripheral sensory nerve excitability produced by propofol. ⋯ Our results have shown that propofol decreases nerve excitability of primary sensory afferents. The technique of threshold tracking revealed that axonal voltage-gated ion channels are significantly affected by propofol and therefore might be at least partially responsible for earlier described analgesic effects.
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The nociceptin/orphanin FQ (N/OFQ) peptide (NOP) receptor was reported to be functionally heterogeneous. We investigated if [Tyr(10)]N/OFQ(1-11), a peptide ligand reported to selectively bind to the high affinity site of (125)I-[Tyr(14)]N/OFQ in rodent brains, can be a tool for revealing the NOP receptor heterogeneity. We have previously founded an NOP receptor subset insensitive to Ro 64-6198 and (+)-5a Compound, two non-peptide NOP agonists, in rat ventrolateral periaqueductal gray (vlPAG) neurons. Here, we examined if [Tyr(10)]N/OFQ(1-11) differentiated (+)-5a Compound-sensitive and -insensitive vlPAG neurons. Certain mu-opioid (MOP) receptor ligands highly competing with [Tyr(10)]N/OFQ(1-11) in binding studies also showed high affinity at expressed heteromeric NOP-MOP receptors. We also examined if [Tyr(10)]N/OFQ(1-11) distinguished heteromeric NOP-MOP receptors from homomeric NOP receptors. ⋯ [Tyr(10)]N/OFQ(1-11) is an NOP full agonist and less potent than N/OFQ. However, it can neither reveal the functional heterogeneity of NOP receptors in vlPAG neurons nor differentiate heteromeric NOP-MOP and homomeric NOP receptors.
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Comparative Study
Exogenous intravascular nitric oxide enhances ventricular function after hemodilution with plasma expander.
This study evaluated the hypothesis that exogenous nitric oxide (NO) supplementation during acute hemodilution with plasma expander (PE) provides beneficial effects on cardiac function. ⋯ NO supplementation in an acute hemodilution with PE has beneficial effects on cardiac performance. However, the NO supplementation effects with a NO donor are dose-independent and short-lasting.
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Comparative Study
The benzomorphan-based LP1 ligand is a suitable MOR/DOR agonist for chronic pain treatment.
Powerful analgesics relieve pain primarily through activating mu opioid receptor (MOR), but the long-term use of MOR agonists, such as morphine, is limited by the rapid development of tolerance. Recently, it has been observed that simultaneous stimulation of the delta opioid receptor (DOR) and MOR limits the incidence of tolerance induced by MOR agonists. 3-[(2R,6R,11R)-8-hydroxy-6,11-dimethyl-1,4,5,6-tetrahydro-2,6-methano-3-benzazocin-3(2H)-yl]-N-phenylpropanamide (LP1) is a centrally acting agent with antinociceptive activity comparable to morphine and is able to bind and activate MOR and DOR. The aim of this work was to evaluate and compare the induction of tolerance to antinociceptive effects from treatment with LP1 and morphine. ⋯ LP1 is a novel analgesic agent for chronic pain treatment, and its low tolerance-inducing capability may be correlated with its ability to bind both the MOR and DOR.