Borvendeg Sebestyen J, Al-Khrasani Mahmoud, Rubini Patrizia, Fischer Wolfgang, Allgaier Clemens, Wirkner Kerstin, Himmel Herbert M, Gillen Clemens, Illes Peter
Rudolf-Boehm-Institute of Pharmacology and Toxicology, University of Leipzig, Haertelstrasse 16-18, D-04107 Leipzig, Germany.
Eur J Pharmacol. 2003 Aug 1;474(1):71-5. doi: 10.1016/s0014-2999(03)02003-x.
The application of cyclophosphamide to rats was used to induce interstitial cystitis. Behavioural studies indicated a strong pain reaction that developed within 2 h and levelled off thereafter causing a constant pain during the following 18 h. Neurons prepared from L6/S1 dorsal root ganglia innervating the urinary bladder responded to the application of capsaicin or alpha,beta-methylene ATP (alpha,beta-meATP) with an increase of intracellular Ca2+ ([Ca2+]i). The [Ca2+]i responses to capsaicin were identical in the dorsal root ganglion cells of cyclophosphamide- and saline-treated rats, whereas alpha,beta-meATP induced less increase in [Ca2+]i in the cyclophosphamide-treated animals than in their saline-treated counterparts. Hence, alpha,beta-meATP-sensitive P2X3 and/or P2X2/3 receptors of L6/S1 dorsal root ganglion neurons were functionally downregulated during subacute pain caused by experimental cystitis. In contrast, capsaicin-sensitive vanilloid 1 receptors did not react to the same procedure. Thoracal dorsal root ganglia, not innervating the urinary bladder, were also unaltered in their responsiveness to alpha,beta-meATP by cyclophosphamide treatment.
