Posted by chemist on June 20, 2005, at 1:00:01
In reply to What is a sigma 1 receptor ??, posted by linkadge on June 19, 2005, at 0:21:06
> Does anyone know what a sigma 1 receptor is ??
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> Linkadgehello there, chemist here...from Urani et al., Eur. J. Pharmacology 486 (2004) 151 - 161: ``The $\sigma_{1}$ receptor is a 223-amino acid protein, cloned in several animal species (naeer et al., 1996; Kekuda et al., 1996) that appeared devoid of analogy with any known mammalian protein. Selective $\sigma_{1}$ receptor ligands exert a potent neuromodulation on intracellular Ca$^{2+}$ mobilisations and excitatory neurotransmitter systems, including norandrenergic, glutamatergic and cholinergic responses (for review, see Maurice et al., 1999).''
...
``In a previous study, we have reported that the antidepressant-like efficacy of igmesine or PRE-084, two $\sigma_{1}$ receptor agonists, measured using the forced swim test, were potentiated in mice injected intracerebroventricularly (i.c.v.) with $\beta_{25-35}$-amyloai peptide (Urani et al., 2002). This enhanced efficacy was attributed to decreased progesterone levels in the hippocampus of $\beta_{25-35}$ animals and suggested that $\sigma_{1}$ agonists, due to their enhanced efficacy, may allow to alleviate the depressive symptoms associated with Alzheimer's disease (Urani et al., 2002). In the present study, these observations were confirmed and extended using the Alzheimer's disease model of rats chronically infused with $\beta$-amyloid-(1-40) protein (Nitta et al., 1994, 1997; Yamada et al., 1995, 1999). We examined the antidepressant-like efficacy of $\sigma_{1}$ receptor agonists, and particularly igmesine and the $\sigma_{1}$ receptor-related neuroactive steroid dehydroepiandrosterone sulfate, on the conditioned fear stress response of rats, as previously reported (Nabeshima et al., 1985; Kamei et al., 1997). The effect of $\beta$-amyloid infusion on brain neurosteroid levels was measures in basal and stressful conditions.''
i do hope that this ref. - and those cited, especially the review by Maurice et al., 1999) - is of use...all the best, chemist
poster:chemist
thread:515346
URL: http://www.dr-bob.org/babble/20050617/msgs/515854.html