Behavioral and neuroendocrine actions of endomorphin-2

Bujdosó, E.; Jászberényi, Miklós; Tömböly, Csaba; Tóth, Géza; Telegdy, Gyula

doi:10.1016/s0196-9781(01)00466-1

Cited by 32 publications

(13 citation statements)

References 43 publications

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“…Hypothalamic corticotrophin-releasing hormone neurons receive direct inhibitory input from b-endorphin producing neurons in the arcuate nucleus, but also regulate corticotrophin-releasing hormone neurons indirectly through noradrenergic mechanisms (Jackson et al, 1990). Naloxone, a non-selective opioid receptor antagonist, induces increases in adrenocorticotropic hormone and cortisol levels, an effect thought to be mediated through the blockade of b-endorphin and enkephalinergic input to corticotrophin-releasing hormone neurons (Bujdoso et al, 2001). In addition, it has also been shown that the arcuate nucleus is a part of an endogenous opioid descending pain suppressing system impacting on the ventrolateral PAG (Sim and Joseph, 1991).…”

Section: Discussionmentioning

confidence: 99%

Personality Trait Predictors of Placebo Analgesia and Neurobiological Correlates

Peciña

Azhar

Love

et al. 2012

Neuropsychopharmacol

165

107

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Personality traits have been shown to interact with environmental cues to modulate biological responses including treatment responses, and potentially having a role in the formation of placebo effects. Here, we assessed psychological traits in 50 healthy controls as to their capacity to predict placebo analgesic effects, placebo-induced activation of m-opioid neurotransmission and changes in cortisol plasma levels during a sustained experimental pain challenge (hypertonic saline infused in the masseter muscle) with and without placebo administration. Statistical analyses showed that an aggregate of scores from Ego-Resiliency, NEO Altruism, NEO Straightforwardness (positive predictors) and NEO Angry Hostility (negative predictor) scales accounted for 25% of the variance in placebo analgesic responses. Molecular imaging showed that subjects scoring above the median in a composite of those trait measures also presented greater placebo-induced activation of m-opioid neurotransmission in the subgenual and dorsal anterior cingulate cortex (ACC), orbitofrontal cortex, insula, nucleus accumbens, amygdala and periaqueductal gray (PAG). Endogenous opioid release in the dorsal ACC and PAG was positively correlated with placebo-induced reductions in pain ratings. Significant reductions in cortisol levels were observed during placebo administration and were positively correlated with decreases in pain ratings, m-opioid system activation in the dorsal ACC and PAG, and as a trend, negatively with NEO Angry Hostility scores. Our results show that personality traits explain a substantial proportion of the variance in placebo analgesic responses and are further associated with activations in endogenous opioid neurotransmission, and as a trend cortisol plasma levels. This initial data, if replicated in larger sample, suggest that simple trait measures easily deployable in the field could be utilized to reduce variability in clinical trials, but may also point to measures of individual resiliency in the face of aversive stimuli such as persistent pain and potentially other stressors.

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Section: Discussionmentioning

confidence: 99%

Personality Trait Predictors of Placebo Analgesia and Neurobiological Correlates

Peciña

Azhar

Love

et al. 2012

Neuropsychopharmacol

165

107

View full text Add to dashboard Cite

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“…It should be pointed out that in the earlier studies endomorphin-2, at low doses (0.25 and 0.5 mg/animal, i.c.v. ), significantly stimulated locomotor activity in mice (Bujdoso et al, 2001). However, a different modality of testing (open field box) was used.…”

Section: Discussionmentioning

confidence: 99%

Antidepressant-Like Effect of Endomorphin-1 and Endomorphin-2 in Mice

Fichna

Janecka

Piestrzeniewicz

et al. 2006

Neuropsychopharmacol

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Endomorphin-1 (Tyr-Pro-Trp-Phe-NH 2 ) and endomorphin-2 (Tyr-Pro-Phe-Phe-NH 2 ) are two recently isolated m-opioid selective peptides with a potent antinociceptive activity, involved in a number of physiological processes, including food intake, vasomotricity, sexual behavior, as well as neuroendocrine and cardiorespiratory functions. The neuroanatomical distribution of endomorphins prompted us to study their antidepressant activity in two animal behavioral models of depression: forced-swimming and tail-suspension tests. In both tests, the intracerebroventricular (i.c.v.) injection of either endomorphin-1 or endomorphin-2 significantly decreased the duration of immobility, interpreted as an expression of 'behavioral despair', which could be related to the depression syndrome. These effects of endomorphins did not result from the stimulation of the animal motor activity. We have also demonstrated that the antidepressant-like effect of endomorphins was antagonized by the universal opioid antagonist, naloxone and the m-opioid receptor selective antagonist, b-funaltrexamine. In contrast, this effect was not antagonized by d-and k-opioid receptor selective antagonists, naltrindole and nor-binaltorphimine, respectively. The results of the present study demonstrate that endomorphin-1 and endomorphin-2 produce potent antidepressant-like effects after i.c.v. injection in mice. We may suggest that endomorphins and the m-opioid receptors might be involved in the physiopathology of depressive disorders, and that the endomorphinergic system could serve as a novel target for the development of antidepressant drugs. Neuropsychopharmacology (2007) 32, 813-821.

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“…Interestingly, the concentration-response curves for endomorphin-1 and endomorphin-2 in mice were of a bell-shaped type (Bujdoso et al, 2001). However, relatively lower concentrations of endomorphin-2 than of endomorphin-1 were used to obtain the same response (Bujdoso et al, 2001), suggesting differences in activation of the -opioid receptor subtypes (Sakurada et al, 1999(Sakurada et al, , 2000 or the involvement of the enkephalinergic or dynorphinergic system (Sanchez-Blazquez et al, 1999;Tseng et al, 2000).…”

Section: A Biological Effects Of Endomorphinsmentioning

confidence: 99%

“…In some studies endomorphins, like morphine, were shown to increase horizontal and vertical activity (i.e., hyperlocomotion) and not to alter grooming activity (Bujdoso et al, 2001(Bujdoso et al, , 2003. Interestingly, the concentration-response curves for endomorphin-1 and endomorphin-2 in mice were of a bell-shaped type (Bujdoso et al, 2001).…”

Section: A Biological Effects Of Endomorphinsmentioning

confidence: 99%