Effect Of Tetramethylpyrazine On Arteriolar Vascular Tension Of Greater Omental In Patients With Preeclampsia

Objective:Preeclampsia(PE)is a hypertensive disorder complicating pregnancy(HDCP).It is a serious complication in obstetrics and poses a serious threat to the health of mothers and infants[1].The basic pathological changes are systemic arteriolar spasm,endothelial injury and is chemia,but the pathogenesis is still not very clear.The effect of tetramethylpyrazine(TMP)on arteriolar vascular tension of greater omental in patients with PE is studied in this research to explore the possible mechanism of BKca channel.Methods:The arteriolar vascular tension test of the isolated human greater omental was performed,vasomotor functions of KCl(80mmol/L),U46619(10-10?10-7mol/L),TMP(10-6-10-2mol/L),IbTX(100?200nmol/L)on the intact and without endothelium arteriole of human greater omental were recorded.The biological signal acquisition and analysis system DMT and PowerLab/8 was used for determining and record its changes.The changes of vascular tension of the NP group(normal pregnancy group),PE group(preeclampsia group),IbTX+NP group(normal pregnancy treated by IbTX)and IbTX+PE group(preeclampsia treated by IbTX)were compared.Results:(1)The contractile function of KCl(80mmol/L)or U46619(10-10?10-7mol/L)on arteriolar vascular ring of greater omental in the PE group was significantly higher than that in the NP group(P<0.01);(2)The relaxation time of KCl(80mmol/L)induced the plateau tension and then recovered to the baseline tension in th PE group was longer than that in the NP group(P<0.01);(3)The contractilefunction of vascular of the PE group and NP group showed concentration dependent manner while U46619 in 10-10?10-7mol/L,and PE group was significantly higher than NP group(P<0.05);(4)IbTX(100nmol/L)had no effect on basic tension on the omental arterioles(P>0.05);(5)After IbTX(100nmol/L)pretreatment,the contractile function of U46619 on the PE group and NP group were both enhanced,and the PE group was higher than in group NP(P<0.05).In different concentrations of U46619,the degree of contraction of vascular rings of PE group was similar to the degree of contraction of vascular rings IbTX+NP group,the Emax(maximum contraction rate)and pD2(sensitivity index)between the two groups showed no significant difference(P>0.05);(6)With the concentration of TMP was 10-6?10-2mol/L,the precontract omental arterial ring in both of the PE group and NP group showed concentration dependent manner,and the PE group was weaker than that of NP group(P<0.05);(7)After IbTX(100nmol/L)pretreatment,the vasodilatation function of TMP on vascular rings in NP+IbTX group was significantly inhibited(P<0.05),while the PE+IbTX group was not inhibited(P>0.05).With the concentration of TMP was 10-6?10-2 mol/L,the vasodilatation function was similar of the PE group,IbTX+NP group and IbTX+PE group,and the Emax showed no significant difference between the three groups(P>0.05);(8)With the concentration of IbTX was 200nmol/L,there were no significant differences of the contraction percentage of TMP between the PE group and NP group(P>0.05);(9)With the concentration of TMP was 10-6?10-2mol/L,most of the basic tension of omental arterioles of the PE group and NP group was not affected.With the concentration of TMP was 10-3 mol/L,some vascular rings occur an abnormal and reversible constriction,and there was no statistically significant difference of Emax between the two groups(P>0.05).The time required for the vascular rings from contraction to self-recovery and be stable at baseline in the PE group was significantly shorter than that in the NP group(p<0.05).Conclusion:(1)The contractile force of the vascular rings increases and the vasodilatation force decreases when the BKca channel is blocked and the activity decreases,suggesting that the contraction function of the omental arteriole is involved in the BKca pathway.(2)The contraction function of the greater omental arteriole increases and the vasodilatation function decreases,which may be related to the decline of BKca activity of the vascular smooth muscle cells in patients with PE.(3)The vasodilatation function of TMP to greater omental arteries may be related to the BKca channel of vascular smooth muscle cells.(4)The basic tension of human greater omental arteries may not be affected by TMP,or abnormal and reversible constriction may occur with TMP at 10-3mol/L.