Article

Rubiscolin-6, a delta opioid peptide derived from spinach Rubisco, has anxiolytic effect via activating sigma1 and dopamine D1 receptors.

Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011, Japan.
Peptides (impact factor: 2.43). 11/2007; 28(10):1998-2003. DOI:10.1016/j.peptides.2007.07.024 pp.1998-2003
Source: PubMed

ABSTRACT Rubiscolin-6 (Tyr-Pro-Leu-Asp-Leu-Phe) is a delta opioid peptide derived from the large subunit of spinach d-ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco). We previously reported that rubiscolin-6 had an analgesic effect and stimulated memory consolidation. Here we show that intraperitoneally (i.p.) or orally administered rubiscolin-6 has an anxiolytic effect at a dose of 10 mg/kg or 100 mg/kg, respectively, in the elevated plus-maze test in mice. The anxiolytic effects of rubscolin-6 after i.p. (10 mg/kg) and oral (100 mg/kg) administration were blocked by a delta opioid receptor antagonist, naltrindole (1 mg/kg, s.c.), suggesting that the anxiolytic activity of rubiscolin-6 is mediated by delta opioid receptor. The anxiolytic effect of rubiscolin-6 (10 mg/kg, i.p.) was also blocked by a dopamine D(1) antagonist, SCH23390 (30 microg/kg, i.p.), but not by a dopamine D(2) antagonist, raclopride (15 microg/kg, i.p.). The anxiolytic effect of rubiscolin-6 (10 mg/kg, i.p.) was blocked by sigma(1) receptor antagonist, BMY14802 (0.5 mg/kg, i.p.) or BD1047 (10 mg/kg, i.p.). Taken together, the anxiolytic effect of rubiscolin-6 is mediated by sigma(1) and dopamine D(1) receptors downstream of delta opioid receptor.

0 0
 · 
0 Bookmarks
 · 
26 Views
  • Source
    Article: Yes, I am ready now: differential effects of paced versus unpaced mating on anxiety and central oxytocin release in female rats.
    Kewir D Nyuyki, Martin Waldherr, Sandra Baeuml, Inga D Neumann
    [show abstract] [hide abstract]
    ABSTRACT: Sexual activity and partner intimacy results in several positive consequences in the context of stress-coping, both in males and females, such as reduced state anxiety in male rats after successful mating. However, in female rats, mating is a rewarding experience only when the estrous female is able to control sexual interactions, i.e., under paced-mating conditions. Here, we demonstrate that sex-steroid priming required for female mating is anxiolytic; subsequent sexual activity under paced mating conditions did not disrupt this anxiolytic priming effect, whereas mating under unpaced conditions increased anxiety-related behavior. In primed females, the release of the neuropeptide oxytocin (OT) within the hypothalamic paraventricular nucleus was found to be elevated and to further increase during paced, but not unpaced mating. Central administration of an OT receptor antagonist partly prevented priming/mating-induced anxiolysis indicating the involvement of brain OT in the anxiolysis triggered by priming and/or sexual activity.These findings reveal that the positive consequences of mating in females are dependent on her ability to control sexual interactions, and that brain OT release is at least in part the underlying neurobiological correlate.
    PLoS ONE 01/2011; 6(8):e23599. · 4.09 Impact Factor
Data provided are for informational purposes only. Although carefully collected, accuracy cannot be guaranteed. The impact factor represents a rough estimation of the journal's impact factor and does not reflect the actual current impact factor. Publisher conditions are provided by RoMEO. Differing provisions from the publisher's actual policy or licence agreement may be applicable.

Keywords

analgesic effect
 
anxiolytic activity
 
anxiolytic effect
 
anxiolytic effects
 
delta opioid peptide
 
delta opioid receptor
 
delta opioid receptor antagonist
 
dopamine D(1)
 
dopamine D(2)
 
elevated plus-maze test
 
large subunit
 
memory consolidation
 
oral
 
orally
 
raclopride
 
Rubiscolin-6
 

Hajime Hirata