Xylazine, an alpha(2)-adrenergic agonist, modulates proliferation of rat thymocytes in vivo and in vitro
Abstract
The effect of xylazine, an alpha (2)-adrenergic agonist, on proliferation of rat thymocytes in vivo and in vitro was examined. It was found that the agonist administered to rats in vivo at doses of 2.5 mg/kg and 5 mg/kg stimulated thymocyte proliferation to suboptimal (0.625 mug/ml) concentrations of concanavalin A (Con A). A similar effect was confirmed in vitro when lower concentrations of xylazine (5 muM) were added to cultures of thymic cells from intact animals in the presence of both suboptimal and optimal (2.5 mug/ml) Con A concentrations. Higher doses in vivo (25 mg/kg) and in vitro (50 muM, 100 muM and 250 muM) significantly inhibited proliferation of thymocytes to Con A. The phenomenon was followed by a decrease in interleukin-2 (IL-2) production (in vivo and in vitro) and down-regulation of IL-2 receptor alpha (IL-2R alpha) expression (in vitro). The exogenous IL-2 completely restored the inhibitory effect of xylazine in vivo was observed. Stimulatory effect of xylazine on p...roliferation of thymocytes was probably mediated through alpha (2)-adrenoreceptors since it was blocked by yohimbine, an alpha (2)-adrenoreceptor antagonist. It seems that the pathways involved in inhibition of thymocyte proliferation by xylazine are more complex because the xylazine-suppressed thymocyte proliferation was potentiated by yohimine.
Keywords:
alpha(2)-adrenergic agonist / thymocytes / proliferation / interleukin-2 production / IL-2R alpha expressionSource:
Methods and Findings in Experimental and Clinical Pharmacology, 2000, 22, 7, 557-562Publisher:
- Prous Science, Sau-Thomson Reuters, Barcelona
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Institution/Community
Fakultet veterinarske medicineTY - JOUR AU - Colić, M AU - Ćupić, Vitomir AU - Pavicić, L AU - Vučević, Dragana AU - Varagić, Vladislav M. PY - 2000 UR - https://vet-erinar.vet.bg.ac.rs/handle/123456789/137 AB - The effect of xylazine, an alpha (2)-adrenergic agonist, on proliferation of rat thymocytes in vivo and in vitro was examined. It was found that the agonist administered to rats in vivo at doses of 2.5 mg/kg and 5 mg/kg stimulated thymocyte proliferation to suboptimal (0.625 mug/ml) concentrations of concanavalin A (Con A). A similar effect was confirmed in vitro when lower concentrations of xylazine (5 muM) were added to cultures of thymic cells from intact animals in the presence of both suboptimal and optimal (2.5 mug/ml) Con A concentrations. Higher doses in vivo (25 mg/kg) and in vitro (50 muM, 100 muM and 250 muM) significantly inhibited proliferation of thymocytes to Con A. The phenomenon was followed by a decrease in interleukin-2 (IL-2) production (in vivo and in vitro) and down-regulation of IL-2 receptor alpha (IL-2R alpha) expression (in vitro). The exogenous IL-2 completely restored the inhibitory effect of xylazine in vivo was observed. Stimulatory effect of xylazine on proliferation of thymocytes was probably mediated through alpha (2)-adrenoreceptors since it was blocked by yohimbine, an alpha (2)-adrenoreceptor antagonist. It seems that the pathways involved in inhibition of thymocyte proliferation by xylazine are more complex because the xylazine-suppressed thymocyte proliferation was potentiated by yohimine. PB - Prous Science, Sau-Thomson Reuters, Barcelona T2 - Methods and Findings in Experimental and Clinical Pharmacology T1 - Xylazine, an alpha(2)-adrenergic agonist, modulates proliferation of rat thymocytes in vivo and in vitro VL - 22 IS - 7 SP - 557 EP - 562 UR - https://hdl.handle.net/21.15107/rcub_veterinar_137 ER -
@article{ author = "Colić, M and Ćupić, Vitomir and Pavicić, L and Vučević, Dragana and Varagić, Vladislav M.", year = "2000", abstract = "The effect of xylazine, an alpha (2)-adrenergic agonist, on proliferation of rat thymocytes in vivo and in vitro was examined. It was found that the agonist administered to rats in vivo at doses of 2.5 mg/kg and 5 mg/kg stimulated thymocyte proliferation to suboptimal (0.625 mug/ml) concentrations of concanavalin A (Con A). A similar effect was confirmed in vitro when lower concentrations of xylazine (5 muM) were added to cultures of thymic cells from intact animals in the presence of both suboptimal and optimal (2.5 mug/ml) Con A concentrations. Higher doses in vivo (25 mg/kg) and in vitro (50 muM, 100 muM and 250 muM) significantly inhibited proliferation of thymocytes to Con A. The phenomenon was followed by a decrease in interleukin-2 (IL-2) production (in vivo and in vitro) and down-regulation of IL-2 receptor alpha (IL-2R alpha) expression (in vitro). The exogenous IL-2 completely restored the inhibitory effect of xylazine in vivo was observed. Stimulatory effect of xylazine on proliferation of thymocytes was probably mediated through alpha (2)-adrenoreceptors since it was blocked by yohimbine, an alpha (2)-adrenoreceptor antagonist. It seems that the pathways involved in inhibition of thymocyte proliferation by xylazine are more complex because the xylazine-suppressed thymocyte proliferation was potentiated by yohimine.", publisher = "Prous Science, Sau-Thomson Reuters, Barcelona", journal = "Methods and Findings in Experimental and Clinical Pharmacology", title = "Xylazine, an alpha(2)-adrenergic agonist, modulates proliferation of rat thymocytes in vivo and in vitro", volume = "22", number = "7", pages = "557-562", url = "https://hdl.handle.net/21.15107/rcub_veterinar_137" }
Colić, M., Ćupić, V., Pavicić, L., Vučević, D.,& Varagić, V. M.. (2000). Xylazine, an alpha(2)-adrenergic agonist, modulates proliferation of rat thymocytes in vivo and in vitro. in Methods and Findings in Experimental and Clinical Pharmacology Prous Science, Sau-Thomson Reuters, Barcelona., 22(7), 557-562. https://hdl.handle.net/21.15107/rcub_veterinar_137
Colić M, Ćupić V, Pavicić L, Vučević D, Varagić VM. Xylazine, an alpha(2)-adrenergic agonist, modulates proliferation of rat thymocytes in vivo and in vitro. in Methods and Findings in Experimental and Clinical Pharmacology. 2000;22(7):557-562. https://hdl.handle.net/21.15107/rcub_veterinar_137 .
Colić, M, Ćupić, Vitomir, Pavicić, L, Vučević, Dragana, Varagić, Vladislav M., "Xylazine, an alpha(2)-adrenergic agonist, modulates proliferation of rat thymocytes in vivo and in vitro" in Methods and Findings in Experimental and Clinical Pharmacology, 22, no. 7 (2000):557-562, https://hdl.handle.net/21.15107/rcub_veterinar_137 .