The effect of chronic treatment with naltrindole, a selective δ-opioid antagonist, on μ-opioid receptor-mediated antinociception in diabetic mice

1993 ◽  
Vol 113 (2) ◽  
pp. 167-171 ◽  
Author(s):  
Junzo Kamei ◽  
Naoya Kawashima ◽  
Yuriko Iwamoto ◽  
Tsutomu Suzuki ◽  
Hiroshi Nagase ◽  
...  
Keyword(s):  
Opioid Receptor ◽  
Chronic Treatment ◽  
Opioid Antagonist ◽  
Diabetic Mice ◽  
Μ Opioid Receptor

The effect of chronic treatment with naltrindole on μ-opioid receptor-mediated antinociception in diabetic mice

1994 ◽  
Vol 53 ◽  
pp. S85-S86
Author(s):  
J Kamei ◽  
N Kawashima ◽  
Y Iwamoto ◽  
T Suzuki ◽  
H Nagase ◽  
...  
Keyword(s):  
Opioid Receptor ◽  
Chronic Treatment ◽  
Diabetic Mice ◽  
Μ Opioid Receptor

Inflammation-reactive astrocytes can be restored with a three drug combination

2014 ◽  
Vol 5 (3) ◽  
pp. 209-209
Author(s):  
E. Hansson ◽  
L. Block ◽  
U. Björklund ◽  
B. Biber
Keyword(s):  
Opioid Receptor ◽  
Primary Cultures ◽  
Reactive Astrocytes ◽  
Opioid Antagonist ◽  
Opioid Agonist ◽  
Cell Parameters ◽  
Ultralow Concentrations ◽  
Inflammatory State ◽  
Μ Opioid Receptor

Abstract Aims In inflammation-reactive astrocytes the cell parameters, Ca2+ signalling, Na+ transporters, cytoskeleton, and release of proinflammatory cytokines are affected. We want to re-establish these parameters with agents, which might have a potential to restore the cells back to a normal non-inflammatory level. Methods Astrocytes in primary cultures were incubated with lipopolysaccharide (LPS) (10 ng/ml) for 24 h to become inflammation-reactive. Different parameters were analysed to verify this inflammation: Ca2+ signalling, Na+/K+-ATPase expression, actin filament organization, and interleukin-1beta release (IL-1β). Results We have used an opioid agonist, endomorphin-1, that stimulates the Gi/o protein of the μ-opioid receptor, an opioid antagonist, naloxone, that inhibits the Gs protein of the μ-opioid receptor in ultralow concentrations, and an anti-epileptic agent, levetiracetam, that counteracts the release of IL-1β. The combination of these three agents managed to activate the Gi/o protein and Na+/K+-ATPase activity, inhibit the Gs protein, and decrease the release of IL-1β. The disorganized actin filaments were restored. Conclusions The findings that the important cell parameters in astrocytes were restored back to their normal non-inflammatory state after the cells were treated with the inflammatory agent LPS could be of clinical significance. It may be useful for the treatment of neuroinflammation and also maybe of long-term pain. The astrocyte networks play a significant role and therefore a well-working intercellular Ca2+ signalling is of utmost importance. Significance These findings put new potential drug regimens towards treatment of neuroinflammation and long-term pain into focus.

Sow housing, behaviour and productivity are related to opioid receptor densities

1992 ◽  
Vol 1992 ◽  
pp. 55-55
Author(s):  
A.J. Zanella ◽  
D.M. Broom ◽  
J.C. Hunter
Keyword(s):  
Social Isolation ◽  
Opioid Receptor ◽  
Opioid Receptors ◽  
Chronic Treatment ◽  
Opioid Antagonist ◽  
Post Mortem ◽  
Behavioural Responses ◽  
Opioid Agonists ◽  
Commercial Farms ◽  
Kappa Receptor

Stereotypies such as bar-biting and sham-chewing, inactivity and unresponsiveness are behavioural responses to confinement in pigs. A link between stereotypies and opioids in sows, has been established by Cronin et al.,(1986) who found that the opioid antagonist naloxone inhibited some stereotypies. Stereotypies exhibited different degrees of resistance to the disruption by naloxone, in Cronin's experiment. Modulation of opioid receptors can be influenced by chronic treatment with opioid agonists and antagonists (Blanchard, and Chang,1988). Similarly, opioid receptors can be up or down-regulated by stressful stimuli such as restraint, electric footshock or social isolation (Zeman et al., 1988). In the study reported here mu, delta and kappa receptor densities and affinity were measured post-mortem. A comparison was made between sows which had been tethered or group-housed on commercial farms. The receptor densities were also compared with the behaviour which tethered sows had shown during the latter stages of pregnancy, as well as with their reproductive peformance.

scholarly journals Ligand-induced μ opioid receptor internalization in enteric neurons following chronic treatment with the opiate fentanyl

2013 ◽  
Vol 91 (6) ◽  
pp. 854-860 ◽  
Author(s):  
Laura Anselmi ◽  
Ingrid Jaramillo ◽  
Michelle Palacios ◽  
Jennifer Huynh ◽  
Catia Sternini
Keyword(s):  
Opioid Receptor ◽  
Chronic Treatment ◽  
Receptor Internalization ◽  
Enteric Neurons ◽  
Μ Opioid Receptor

Effects of a μ-opioid receptor agonist on G-protein activation in streptozotocin-induced diabetic mice

2000 ◽  
Vol 401 (1) ◽  
pp. 55-58 ◽  
Author(s):  
Masahiro Ohsawa ◽  
Hirokazu Mizoguchi ◽  
Minoru Narita ◽  
Michiko Narita ◽  
Junzo Kamei ◽  
...  
Keyword(s):  
G Protein ◽  
Opioid Receptor ◽  
Receptor Agonist ◽  
Diabetic Mice ◽  
Protein Activation ◽  
Opioid Receptor Agonist ◽  
G Protein Activation ◽  
Μ Opioid Receptor

scholarly journals Expression and subcellular localization of the μ-opioid receptor in equine spermatozoa: evidence for its functional role

Reproduction ◽  
2005 ◽  
Vol 129 (1) ◽  
pp. 39-49 ◽  
Author(s):  
Maria Albrizio ◽  
Antonio Ciro Guaricci ◽  
Filippo Maritato ◽  
Raffaele Luigi Sciorsci ◽  
Gaetano Mari ◽  
...  
Keyword(s):  
Opioid Receptor ◽  
Opioid Antagonist ◽  
Computer Assisted ◽  
Sperm Cells ◽  
Exact Nature ◽  
Sperm Analysis ◽  
Head Displacement ◽  
Μ Opioid Receptor ◽  
High Degree ◽  
Lateral Head

The development of fertilizing ability in sperm cells is associated with changes in the plasma membrane. However, to date the exact nature of sequentially activated primary receptors and channels and the signal transduction pathways derived from these remains elusive. We analyzed the expression and localization of the μ-opioid receptossr in equine spermatozoa. A transcript corresponding to the third extracellular loop that selectively binds μ agonists was amplified, sequenced and compared with the known sequences in humans, rats and cattle. The amplification product showed a high degree of nucleotide conservation. By immunofluorescence, μ-opioid receptor labeling was found on the sperm head and on the tail and disappeared in the acrosomal region of acrosome-reacted sperm cells. Immunoblotting revealed two bands of 50 and 65 kDa. Effects of the opioid antagonist naloxone on motility and on viability and capacitation/acrosome reaction were investigated by computer-assisted sperm analysis and Hoechst 33258/chlortetracycline (H258/CTC) staining. Progressive motility was significantly reduced after 3 h incubation in 10−3 M naloxone (P < 0.05), whereas it increased significantly after 5 h in 10−8 M naloxone (P < 0.05). Sperm velocity at 5 h was significantly reduced by the addition of 10−3 M naloxone (P < 0.05), but increased significantly in the presence of 10−8 M (P < 0.001). Curvilinear velocity and amplitude of lateral head displacement in spermatozoa incubated in the presence of naloxone were not indicative of hyperactivation. H258/CTC staining showed that 10−8 M naloxone significantly stimulated capacitation (P < 0.01) after 3 h. However, it had no effect on sperm cell viability and acrosomal status. Overall, this study provides the first evidence that the μ-opioid receptor is expressed in equine spermatozoa and that naloxone significantly affects motility and capacitation.

scholarly journals A Subregion of the Parabrachial Nucleus Partially Mediates Respiratory Rate Depression from Intravenous Remifentanil in Young and Adult Rabbits

2017 ◽  
Vol 127 (3) ◽  
pp. 502-514 ◽  
Author(s):  
Justin R. Miller ◽  
Edward J. Zuperku ◽  
Eckehard A. E. Stuth ◽  
Anjishnu Banerjee ◽  
Francis A. Hopp ◽  
...  
Keyword(s):  
Respiratory Rate ◽  
Opioid Receptor ◽  
Receptor Activation ◽  
Pattern Generation ◽  
Respiratory Pattern ◽  
Parabrachial Nucleus ◽  
Opioid Antagonist ◽  
Opioid Administration ◽  
Bötzinger Complex ◽  
Μ Opioid Receptor

Abstract Background The efficacy of opioid administration to reduce postoperative pain is limited by respiratory depression. We investigated whether clinically relevant opioid concentrations altered the respiratory pattern in the parabrachial nucleus, a pontine region contributing to respiratory pattern generation, and compared these effects with a medullary respiratory site, the pre-Bötzinger complex. Methods Studies were performed in 40 young and 55 adult artificially ventilated, decerebrate rabbits. We identified an area in the parabrachial nucleus where α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid microinjections elicited tachypnea. Two protocols were performed in separate sets of animals. First, bilateral microinjections of the μ-opioid receptor agonist [D-Ala,2 N-MePhe,4 Gly-ol]-enkephalin (100 μM) into the “tachypneic area” determined the effect of maximal μ-opioid receptor activation. Second, respiratory rate was decreased with continuous IV infusions of remifentanil. The opioid antagonist naloxone (1 mM) was then microinjected bilaterally into the “tachypneic area” of the parabrachial nucleus to determine whether the respiratory rate depression could be locally reversed. Results Average respiratory rate was 27 ± 10 breaths/min. First, [D-Ala,2 N-MePhe,4 Gly-ol]-enkephalin injections decreased respiratory rate by 62 ± 20% in young and 45 ± 26% in adult rabbits (both P &lt; 0.001). Second, during IV remifentanil infusion, bilateral naloxone injections into the “tachypneic area” of the parabrachial nucleus reversed respiratory rate depression from 55 ± 9% to 20 ± 14% in young and from 46 ± 20% to 18 ± 27% in adult rabbits (both P &lt; 0.001). The effects of bilateral [D-Ala,2 N-MePhe,4 Gly-ol]-enkephalin injection and IV remifentanil on respiratory phase duration in the “tachypneic area” of the parabrachial nucleus was significantly different from the pre-Bötzinger complex. Conclusions The “tachypneic area” of the parabrachial nucleus is highly sensitive to μ-opioid receptor activation and mediates part of the respiratory rate depression by clinically relevant administration of opioids.

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