The effects of levosimendan on hemodynamic variables determined during infusion of dexmedetomidine in isoflurane-anesthetized rats

In this study, we investigated the effects of levosimendan (L) on hemodynamic variables determined during infusion of dexmedetomidine (D) in isoflurane (I)-anesthetized rats.Eighteen female Wistar rats were divided into 3 groups. Rats were mechanically ventilated (peak pressure;10±2 cmH2O, RR; 60/min, FiO2;1.0) after performing cannulation and tracheostomy. After obtaining baseline hemodynamic values, Group I received I(1.4%); Group ID received I (1.4%) + D (1 µg/kg/min); Group IDL received I (1.4%) + D (1µg/kg/min) + L (0.3 µg/kg/min) for 60 min. Values of systolic (SAP), diastolic (DAP) and mean arterial pressure (MAP), (mm Hg), and heart rate (HR; beat /min) were recorded with 5 min intervals. The data were given as mean±SE and/or (%). One way analysis of variance, Tukey-Kramer and paired t tests were used. p<0.05 was considered significant.No statistical significance was found in regard to baseline hemodynamic values among the groups (p>0.05). At the 60. min of infusion of study drugs, HR of group ID (176±12) was lower than that of group I (237±19), (p<0.05) and DAP of group IDL (67±5) was higher than that of group I (48±4), (p<0.05). Within groups, at the 60. min of infusion of study drugs, in group I, SAP (80±3 vs. 71±2 [90.0%], p=0.03), DAP (59±4 vs. 48±4 [81.8%], p=0.049), and MAP (69±4 vs. 57±4 [83.6%], p=0.03), and in group ID, HR (206±12 vs. 176±12 [85.8%], p=0.008) were significantly decreased compared to baseline values. Additionally, in group I, HR (12%) and in group IDL, HR (7%), SAP (14%), DAP (28%) and MAP (20%) were increased, and in group ID, SAP (5%), DAP (2%) and MAP (2%) were decreased without any statistical significance.In rats, I decreased systemic arterial pressure and D decreased HR. The decline in systemic arterial pressure caused by I and the decrease in HR caused by D were not observed after addition of L infusion. Our results show that administration of L has favorable effects on hemodynamic depression which has induced by I and/or D in rats.