Effect of propofol on hypoxic pulmonary vasoconstriction in rats / 中华麻醉学杂志

ABSTRACT

Objective To investigate the effect of propofol on hypoxic pulmonary vasoconstriction(HPV)and assess the underlying mechanism in rats.Methods Twenty male SD rats weighing 300-400 g were.anesthetizedwith intraperitoneal phenobarbital.Heart and lungs were removed after thoracotomy.Pulmonary.arterial rings 4 mmin length and 1.0-1.4 mm in diameter were prepared and suspended in Earl solution maintained at 37℃ with a pHof 7.40 and aerated with 20% O_2-5% CO_2-25% N_2.The rings were stimulated with phenylephrine(PE)10~(-6)mol?L~(-1) with different preloads(300,500,700,900,1 100 mg).The isometric tension of the arterial rings wasmeasured.The optimal preload was determined to be 900 mg which allowed best contractility.Hypoxia was inducedby aerating the solution with 95% N_2-5% CO_2 and the flow rate was adjusted to maintain PO_2 of the solution at40-20 mm Hg and pH at 7.40.HPV of the rings were recorded.Then propofol was added to achieve a finalconcentration of 1,3,10,30,100 ?mol?L~(-1) and HPV was again induced and the changes in HPV wererecorded.In addition the effects of propofol(10,30 ?mol?L~(-1))on vasoconstriction produced by KCI and PE werealso measured.Results The lower doses of propofol(10 ?mol?L~(-1))significantly inhibited HPV(P