Zde - 2. lékařská fakulta - Univerzita Karlova

P-18. SENSORY VASOPRESSIN AND OXYTOCIN UNVEILED IN RATSForostyak O. 1,2 , Forostyak S. 2 , Arboleda D. 2 , Dayanithi G. 2,3 , Sykova E. 1,21 Department of Neuroscience, Charles University, Second Medical Faculty, Prague, Czech Republic;2 Institute of Experimental Medicine Academy of Sciences of the Czech Republic, v.v.i., Prague, CzechRepublic; 3 Institut National de la Santé et de la Recherche Médicale, Unité de rechercheU710,Université Montpellier 2, F-34095 Montpellier cedex 5; and Ecole Pratique des Hautes Etudes,Paris, FranceSupervisor: prof. MUDr. Eva Syková, DrSc., FCMAIntroduction: The neurohormones, vasopressin (AVP) and oxytocin (OT) exert many importantcognitive and physiological functions. Both AVP and OT have been reported to have analgesic effect,however the mechanisms, underlying this effect remain unclear. Dorsal root ganglia (DRG) areintegrative centres containing the cell bodies of sensory neurons receiving somatic sensationinformation from the periphery and transmitting them to the spinal cord.Aims: In this study we used newly generated transgenic rats (AVP-eGFP, OT-eCFP and OT-mRFP1)tagged by a visible fluorescent proteins to study the role of OT and AVP in the dorsal root ganglianeurons.Materials and Methods: Using Fura-2 fast fluorescence microspectrofluorimetry, we havecharacterized [Ca2 + ] i responses in single DRG neurons isolated from transgenic and nontransgenicrats and cultured in vitro. Immunocytochemistry, fluorescence microscopy, and confocal imaging wereemployed to visualize fluorescent AVP and OT, as well as a number of cell markers.Results: Our results showed that both AVP and OT are expressed and can be visualized in the dorsalroot ganglia neurons (both in freshly isolated and cultures in vitro up to 5 days). The immunostainingagainst neuronal markers (NF160, bIII tubulin, NeuN) were co-localized with the endogenous AVPeGFP-,OT-eCFP- and OT-mRFP1 fluorescence, as well as with the immunostainings against AVPand OT. The [Ca2 + ] i measurements from these neurons (between 2 and 120 hours) revealed thatAVP/OT-responsive neurons responded also to the applications of capsaicin (TRPV1 receptoragonist), indicating a role of these neuropeptides in nociception. The immunostaining against TRPV1receptor was co-localized with AVP and OT and with the endogenous AVP-eGFP-, OT-eCFP- and OTmRFP1fluorescence. The expression of OT in DRG neurons increased significantly during pregnancyand lactation. All the above findings were confirmed in a series of control experiments usingnontransgenic Wistar rats.Conclusions: We report for the first time that both AVP and OT are expressed and can be visualizedin the nociceptive dorsal root ganglia neurons in rats, and that the expression of oxytocin significantlyincreases during pregnancy and lactation.Support: PITN-GA-2008-214003; GACR P303/11/0192, GACR P304/12/G069.50