交感神经化学性损毁对SHR血压和尾动脉平滑肌细胞静息Em的影响

Effects of chemical sympathectomy on blood pressure and resting membrane potential of caudal artery muscle cells in SHR

在１６℃状况下（一种抑制Ｎａ￣＋，Ｋ￣＋－ＡＴＰ酶的步骤），成年自发性高血压大鼠（ＳＨＲ）的尾动脉平滑肌细胞静息膜电位（Ｅｍ）绝对值显著小于同龄ＷｉｓｔａｒＫｙｏｔｏ（ＷＫＹ）大鼠。在ＳＨＲ发育早期皮下注射６－羟多巴胺（６－ｈｙｄｒｏｘｙｄｏｐａｍｉｎｅ６－ＯＨＤＡ）损毁交感神经，其成年后的１６℃Ｅｍ值与ＷＫＹ组无明显差异，同时血压也显著低于未损毁组而接近ＷＫＹ水平，但血压和１６℃Ｅｍ二者的变化不相关（相关系数ｒ＝－０．２１，Ｐ＞０．０５）。另一方面，损毁成年ＳＨＲ交感神经不影响其１６℃Ｅｍ，血压也仅有轻度下降。上述结果表明，ＳＨＲ高血压的发生与其发育早期交感神经的营养性作用有关，但这种作用可能与其动脉平滑肌细胞静息Ｅｍ的影响无关。

The resting membrane potential(Em)of caudal arteries from 24 to 25-week-old spont aneously hypertensive rats(SHRs)had a less negative value than that of Wistar-Kyoto rats(WKYs)controlS when measured at 16℃(a procedure used to inhibit the Na￣+,K￣+-ATPase),Neonatal chemical sympathectomy of SHRs with 6-hydroxydopa-mine(6-OHDA)prevented the development of hypertension and the aboye-mentioned abnormal Em,but there was no correlation between them.In SHRs which had been given repeated injections of 6-OHDA between the ages of 12 and 18 weeks,the Em measure-ments were not significantly different from those of age-matched untreated SHRs,onlywith a little lowering of blood pressure,The data suggested that the sympathetic nervesare involved in the development of hypertension in SHR through its trophic effect onthe arteries in young SHR, which may be not related to its influence on the restingmembrane potential in artery smooth muscle cells.