Effect of interleukin-1 on contractile function of rat thoracic aorta / 中华麻醉学杂志

ABSTRACT

Objective To investigate the effect of interleukin-1 (IL-1) on contractile function of rat thoracic aorta.Methods Forty male Sprague-Dawley rats,weighing 250-300 g,were sacrificed to obtain the thoracic aortic rings.The experiment was performed in 2 parts.Part Ⅰ The thoracic aortic rings were divided into 2 segments and randomly divided into 2 groups (n =20 each)control group and IL-1 group.In IL-1 group,the thoracic aortic rings were incubated with Kreb solution containing 20 ng/ml IL-1 for 2 h,and contracted with cumulative concentrations of phenylephrine,ranging from 10-9 to 10-5mol/L.In control group,the thoracic aortic rings were incubated with Kreb solution for 2 h,and contracted with cumulative concentrations of phenylephrine,ranging from 10 9 to 10-5mol/L.Part Ⅱ The thoracic aortic rings were divided into 3 segments and randomly divided into 3 groups (n=20 each)IL-1 group,IL-1+ L-NAME (the NOS inhibitor) group and IL-1 +cyclooxygenase inhibitor indomethacin group (IL-1 +Ⅰgroup).The thoracic aortic rings were incubated with Kreb solution containing 20 ng/ml IL-1 for 1.5 h in the three groups.In addition,in IL-1 +L-NAME and IL-1 +Ⅰ groups,the thoracic aortic rings were incubated for 30 min with Kreb solution containing 100 μmol/L L-NAME and 2.5 mmol/L indomethacin,respectively.Contraction of the thoracic aorta was then induced with cumulative concentrations of phenylephrine,ranging from 10 9 to 10-5 mol/L.In group IL-1,the thoracic aortic rings were incubated with Kreb solution.The maximum contractile tension of the thoracic aortic rings was recorded at each concentration of phenylephrine,and the percentage of the maximum contractile tension at the concentration of 10-6 mol/L in group C was obtained.Results Part Ⅰ The percentage of contractile tension at phenylephrine 10-s,10-7,l0 6 and 10-5mol/L was significantly decreased in IL-1 group as compared with C group.Part Ⅱ The percentage of contractile tension at phenylephrine 10-7,10-6 and 10-5mol/L was significantly increased in IL-1+L-NAME and IL-1+I groups as compared with IL-1 group.Conclusion IL-1 can inhibit the contraction of rat thoracic aorta,and promoted production of NO and prostacyclin may be involved in the mechanism.