Long-term effects of Dexmedetomidin on the expression of apoptosis-regulating proteins after incomplete cerebral ischemia in rats

This study investigates the effect of the α2-adrenozeptor agonist Dexmedetomidine on the expression of the apoptosis-regulating proteins Bax, p53, Bcl-2 and Mdm-2 following incomplete cerebral ischemia in rats within a period of 28 days from the insult. 72 fasted male Sprague-Dawley rats (400 g) were randomly assigned to one of the following groups: Group 1: (n = 32, controls): fentanyl and N2O/O2 (FiO2 = 0.33)Group 2: (n = 32, dexmedetomidine) : fentanyl and N2O/O2 (FiO2 = 0.33), administration of dexmedetomidine intraperitoneal 30 min before ischemia, the animals of these groups were randomly assigned in groups (n = 8) with a postischemic observation period of 1, 3, 7 or 28 days.Group 3: (n = 8, naive): without treatment, show reference valueThe apoptosis-regulating proteins Bax, p53, Bcl-2 and Mdm-2 in the hippocampal regions were analysed qualitatively and quantitatively by using the Immunfluorescence-technique and the Western-Blot-technique. The concentration of the pro-apoptotic protein Bax is decreased in the hippocampus for at least 28 days after cerebral ischemia. The anti-apototic Bcl-2 protein was increased during the first three days after cerebral ischemia in group 2 compared to group 1. The Mdm-2 protein of group 2 was significantly increased during the whole period of investigation in the Western-Blot-analysis.