Hoffmann, R. A wiki for the life sciences where authorship matters. Nature Genetics (2008)

Editor

Personal info

View

About

Terms

Javascript disabled

Please enable Javascript support in your browser to use this application.

Instructions on how to enable JavaScript on different browsers can be found here: http://www.google.com/support/bin/answer.py?answer=23852.

[edit this page]

Frye, C.A. et al.

Estradiol benzoate potentiates neuroactive steroids' effects on pain sensitivity.

Progesterone (P), its metabolites, and other neuroactive steroids alter pain thresholds consistent with their efficacies at modulating gamma-aminobutyric acid (GABAA) receptor complexes. We investigated whether estradiol benzoate (EB) potentiates low dosages of neuroactive steroids' effects on pain. Subcutaneous EB (10 micrograms) or sesame oil vehicle was administered to ovariectomized Long-Evans rats (n = 40) 48 h before intracerebroventricular (ICV) infusion of a neuroactive steroid (0.0, 0.1, 0.3, or 0.5 micrograms) in cyclodextrin vehicle. Neuroactive steroids (listed from greatest to least efficacious at GABAA receptor complexes) were THP [5 alpha-pregnan-3 alpha-ol-20-one], THDOC [5 alpha-pregnan-3 alpha, 21-diol-20-one], DHP [5 alpha-pregnan-3,20-dione], P [4-pregnen-3,20-dione], and DHEAS [5-androsten-3 beta-ol-17-one sulfate]. Pain sensitivity was assessed using the radiant heat tail-flick method before and 20 and 60 min following infusion. Estradiol benzoate interacted with the neuroactive steroids to alter tail-flick latencies. In particular, EB potentiated the antinociceptive effect of THP and DHP by significantly increasing tail-flick latencies above those of non-EB-treated animals. A similar pattern of increased tail-flick latencies occurred in EB-primed animals that received THDOC. Estradiol benzoate less consistently altered the pain threshold of animals administered P, which is less effective at modulating GABAergic activity. Conversely, EB increased the nociceptive effect of the neurosteroid DHEAS, an allosteric antagonist of GABAA receptor complexes, by significantly decreasing tail-flick latencies of EB-compared to vehicle-primed rats. Thus, EB priming potentiated neuroactive steroids' effects on pain threshold.[1]

References

Estradiol benzoate potentiates neuroactive steroids' effects on pain sensitivity. Frye, C.A., Duncan, J.E. Pharmacol. Biochem. Behav. (1996) [Pubmed]

Annotations and hyperlinks in this abstract are from individual authors of WikiGenes or automatically generated by the WikiGenes Data Mining Engine. The abstract is from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.About WikiGenes Open Access Licence Privacy Policy Terms of Use apsburg

The world's first wiki where authorship really matters (Nature Genetics, 2008). Due credit and reputation for authors. Imagine a global collaborative knowledge base for original thoughts. Search thousands of articles and collaborate with scientists around the globe.