Cerebrospinal fluid beta-endorphin in models of hyperalgesia in the rat. Export

@article{citeulike:456098, abstract = {Cerebrospinal fluid (CSF) obtained by acute percutaneous puncture of the cisternal membrane of the halothane anesthetized rat has low but measurable concentrations of beta-endorphin-like immunoreactivity (beta-EPir: 32.8 +/- 3.0 pmol/l). Chromatographic separation of beta-EPir showed that authentic beta-endorphin1-31 was the main component of beta-EPir in cisternal CSF. Subcutaneous injection of 5\% formalin in the hind paws did not increase beta-EPir in cisternal CSF. Rats with tactile paw hyperalgesia evoked by unilateral ligation of the L5/6 nerve roots 2 weeks earlier had beta-EPir concentrations that did not differ from sham operated or unoperated control animals. In contrast, capsaicin injected in the hindpaws increased the mean beta-EPir concentration compared to saline injections (P = 0.006) 45 min after emerging from anesthesia following injection. These results show that acute activation of C fibers (by capsaicin) will evoke the release of beta-endorphin into the CSF, suggesting activation of the beta-endorphin terminal systems in the brain/midbrain. The failure of formalin injections to release beta-EPir to CSF may be due to specificity of the afferent stimulus evoking beta-EPir release, a lower stimulus intensity, and/or the duration of the stimulus generated by formalin. The normal concentrations of beta-EPir found in the hyperalgesic state following nerve injury suggest that the supraspinal beta-endorphin system does not display tonic changes under such conditions.}, address = {Anesthesiology Research Laboratory, University of California San Diego, La Jolla, CA 92093-0818, USA.}, author = {Bach, F. W. and Chaplan, S. R. and Jang, J. and Yaksh, T. L.}, citeulike-article-id = {456098}, citeulike-linkout-0 = {http://view.ncbi.nlm.nih.gov/pubmed/12506417}, citeulike-linkout-1 = {http://www.hubmed.org/display.cgi?uids=12506417}, day = {22}, issn = {0167-0115}, journal = {Regul Pept}, keywords = {brain, csf, endorphin, rat}, month = {September}, number = {1}, pages = {79--86}, posted-at = {2006-01-05 08:13:54}, priority = {3}, title = {Cerebrospinal fluid beta-endorphin in models of hyperalgesia in the rat.}, url = {http://view.ncbi.nlm.nih.gov/pubmed/12506417}, volume = {59}, year = {1995} }

TY - JOUR ID - citeulike:456098 L3 - citeulike-article-id:456098 N2 - Cerebrospinal fluid (CSF) obtained by acute percutaneous puncture of the cisternal membrane of the halothane anesthetized rat has low but measurable concentrations of beta-endorphin-like immunoreactivity (beta-EPir: 32.8 +/- 3.0 pmol/l). Chromatographic separation of beta-EPir showed that authentic beta-endorphin1-31 was the main component of beta-EPir in cisternal CSF. Subcutaneous injection of 5% formalin in the hind paws did not increase beta-EPir in cisternal CSF. Rats with tactile paw hyperalgesia evoked by unilateral ligation of the L5/6 nerve roots 2 weeks earlier had beta-EPir concentrations that did not differ from sham operated or unoperated control animals. In contrast, capsaicin injected in the hindpaws increased the mean beta-EPir concentration compared to saline injections (P = 0.006) 45 min after emerging from anesthesia following injection. These results show that acute activation of C fibers (by capsaicin) will evoke the release of beta-endorphin into the CSF, suggesting activation of the beta-endorphin terminal systems in the brain/midbrain. The failure of formalin injections to release beta-EPir to CSF may be due to specificity of the afferent stimulus evoking beta-EPir release, a lower stimulus intensity, and/or the duration of the stimulus generated by formalin. The normal concentrations of beta-EPir found in the hyperalgesic state following nerve injury suggest that the supraspinal beta-endorphin system does not display tonic changes under such conditions. IS - 1 JF - Regul Pept SN - 0167-0115 AD - Anesthesiology Research Laboratory, University of California San Diego, La Jolla, CA 92093-0818, USA. EP - 86 TI - Cerebrospinal fluid beta-endorphin in models of hyperalgesia in the rat. VL - 59 SP - 79 KW - brain KW - csf KW - endorphin KW - rat AU - Bach, FW AU - Chaplan, SR AU - Jang, J AU - Yaksh, TL PY - 1995/09/22/ UR - http://view.ncbi.nlm.nih.gov/pubmed/12506417 ER -