scholarly journals Interactions Between Opioids and Dextroamphetamine on Locomotor Activity: Influence of an Opioid's Relative Efficacy at the Mu Receptor

2022 ◽  
Vol 12 ◽  
Author(s):  
Mark A. Smith ◽  
Shannon L. Ballard ◽  
Clarise F. Ballesteros ◽  
Samantha A. Bonge ◽  
Alexander T. Casimir ◽  
...  
Keyword(s):  
Locomotor Activity ◽  
Opioid Receptor ◽  
Additive Model ◽  
Behavioral Effects ◽  
Male Rats ◽  
Relative Efficacy ◽  
High Efficacy ◽  
Kappa Agonist ◽  
Mu Receptor ◽  
Opioid Receptor Antagonists

Opioids and stimulants are often used in combination for both recreational and non-recreational purposes. High-efficacy mu opioid agonists generally increase the behavioral effects of stimulants, whereas opioid receptor antagonists generally attenuate the behavioral effects of stimulants; however, less is known regarding the interactions between stimulants and opioids possessing low to intermediate efficacy at the mu receptor. The purpose of this study was to examine the role of an opioid's relative efficacy at the mu receptor in altering the behavioral effects of dextro(d-)amphetamine. To this end, opioids possessing a range of relative efficacy at the mu receptor were examined alone and in combination with cumulative doses of d-amphetamine on a test of open-field, locomotor activity in male rats. Levorphanol, buprenorphine, butorphanol, nalbuphine, (-)-pentazocine, (-)-metazocine, (-)-cyclazocine, (-)-NANM, and nalorphine increased the locomotor effects of d-amphetamine in either an additive or greater-than-additive manner according to an effect-additive model. Only the selective, high-efficacy kappa agonist, spiradoline, and the non-selective opioid receptor antagonist, naloxone, failed to increase the effects of d-amphetamine under the conditions examined. These data indicate that opioids possessing a large range of relative efficacy at the mu receptor, including those possessing very low relative efficacy, significantly increase the locomotor effects of d-amphetamine.

Behavioral Effects of Opioid Receptor Antagonists in Psychopathologic States

1983 ◽  
Vol 6 (3) ◽  
pp. 403-414 ◽  
Author(s):  
David S. Janowsky ◽  
Lewis L. Judd ◽  
Leighton Y. Huey ◽  
Samuel Craig Risch ◽  
David S. Segal
Keyword(s):  
Opioid Receptor ◽  
Behavioral Effects ◽  
Receptor Antagonists ◽  
Opioid Receptor Antagonists

Interactions between opioids and cocaine on locomotor activity in rats: influence of an opioid's relative efficacy at the mu receptor

2003 ◽  
Vol 167 (3) ◽  
pp. 265-273 ◽  
Author(s):  
Mark A. Smith ◽  
Keith A. Gordon ◽  
Christopher K. Craig ◽  
Paul A. Bryant ◽  
M. Eric Ferguson ◽  
...  
Keyword(s):  
Locomotor Activity ◽  
Relative Efficacy ◽  
Mu Receptor

Central opioid receptors mediate glucoprivic inhibition of pituitary LH secretion

1997 ◽  
Vol 272 (4) ◽  
pp. E517-E522 ◽  
Author(s):  
K. P. Briski
Keyword(s):  
Receptor Antagonist ◽  
Opioid Receptor ◽  
Hormone Secretion ◽  
Male Rats ◽  
Pituitary Hormone ◽  
Intracerebroventricular Administration ◽  
Receptor Antagonists ◽  
Opioid Receptor Antagonist ◽  
Opioid Receptor Antagonists

The present studies investigated the significance of glucoprivic metabolic signals, particularly those of central origin, to the regulation of pituitary luteinizing hormone (LH). Groups of gonadectomized (GDX) adult male rats were treated with 2-deoxy-D-glucose (2-DG), an inhibitor of glycolysis, by either intravenous (50, 100, or 200 mg/kg) or intracerebroventricular (5, 20, or 100 microg/rat) administration. Systemic drug treatment caused a significant decrease in mean plasma LH levels compared with saline-treated controls. Intracerebroventricular administration of 2-DG was also efficacious in suppressing circulating LH; animals treated with either of the two highest doses of the drug exhibited a significant reduction in plasma LH. In vitro studies examined direct effects of 2-DG on pituitary gonadotrope secretory activity. Exposure of anterior pituitary tissue to 2-DG during short-term perfusion had no significant impact upon either basal or gonadotropin-releasing hormone-stimulated LH release. Finally, groups of GDX rats were pretreated by intracerebroventricular administration of either the nonselective opioid receptor antagonist, naltrexone, or the selective mu-opioid receptor antagonist, beta-funaltrexamine (beta-FNA), before intravenous injection of 2-DG. Both receptor antagonists were observed to attenuate the suppressive effects of 2-DG on circulating LH in these animals. In summary, treatment of GDX rats with the glucose antimetabolite, 2-DG, decreased plasma LH, suggesting that metabolic signaling of cellular glucose oxidation is of physiological importance to the regulation of pituitary hormone secretion. Findings that plasma LH was diminished in animals treated intracerebroventricularly with 2-DG implicate central glucoprivic receptors in neuroendocrine mechanisms governing the reproductive endocrine axis. Attenuation of 2-DG-induced decreases in circulating LH by opioid receptor antagonists suggests that these receptors, particularly the mu-subtype, mediate central effects of glucoprivation on circulating LH.

Estrogen and μ-opioid receptor antagonists counteract the 17β-estradiol-induced licking increase and interferon-γ reduction occurring during the formalin test in male rats

Pain ◽  
2004 ◽  
Vol 111 (1) ◽  
pp. 181-190 ◽  
Author(s):  
Ilaria Ceccarelli ◽  
Paolo Fiorenzani ◽  
Giovanni Grasso ◽  
William R. Lariviere ◽  
Cosimo Massafra ◽  
...  
Keyword(s):  
Opioid Receptor ◽  
Formalin Test ◽  
Interferon Γ ◽  
Male Rats ◽  
Receptor Antagonists ◽  
Opioid Receptor Antagonists ◽  
17Β Estradiol ◽  
Μ Opioid Receptor

scholarly journals Stamina-Enhancing Effects of Human Adipose-Derived Stem Cells

2021 ◽  
Vol 30 ◽  
pp. 096368972110354
Author(s):  
Eun-Jung Yoon ◽  
Hye Rim Seong ◽  
Jangbeen Kyung ◽  
Dajeong Kim ◽  
Sangryong Park ◽  
...  
Keyword(s):  
Physical Activity ◽  
Stem Cells ◽  
Locomotor Activity ◽  
Tissue Injury ◽  
Male Rats ◽  
Adipose Derived Stem Cells ◽  
Sprague Dawley ◽  
Serum Triglycerides

Stamina-enhancing effects of human adipose derived stem cells (hADSCs) were investigated in young Sprague-Dawley rats. Ten-day-old male rats were transplanted intravenously (IV) or intracerebroventricularly (ICV) with hADSCs (1 × 106 cells/rat), and physical activity was measured by locomotor activity and rota-rod performance at post-natal day (PND) 14, 20, 30, and 40, as well as a forced swimming test at PND 41. hADSCs injection increased the moving time in locomotor activity, the latency in rota-rod performance, and the maximum swimming time. For the improvement of physical activity, ICV transplantation was superior to IV injection. In biochemical analyses, ICV transplantation of hADSCs markedly reduced serum creatine phosphokinase, lactate dehydrogenase, alanine transaminase, and muscular lipid peroxidation, the markers for muscular and hepatic injuries, despite the reduction in muscular glycogen and serum triglycerides as energy sources. Notably, hADSCs secreted brain-derived neurotrophic factor (BDNF) and nerve growth factor in vitro, and increased the level of BDNF in the brain and muscles in vivo. The results indicate that hADSCs enhance physical activity including stamina not only by attenuating tissue injury, but also by strengthening the muscles via production of BDNF.

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