模拟失重大鼠比目鱼肌小动脉风各级血管内径的变化

目的 探讨模拟失重是否可引起后肢肌肉小动脉网各级血管内径发生改变及其可逆性。方法 采用墨汁灌注法观察尾部悬吊４ｗｋ（ＳＵＳ－４），悬吊４ｗｋ后恢复１ｗｋ（ＲＥＣ－１）、恢复５ｗｋ（ＲＥＣ－５），以及对照（ＣＯＮ）大鼠比目鱼肌小动脉网各组血管内径的变化。结果 在ＳＵＳ－４组，比目鱼肌的营养动脉、弓状小动脉及Ｖ、Ⅱ级模行小动脉的内径，较ＣＯＮ组分别减小了３１％、２９％、２８％及４１％（均为Ｐ〈０．０１

Changes in Lumen Diameters of Vessels in Arteriolar Network in Rat Soleus Muscle after Simulated Weightlessness

Objective. To elucidate whether simulated weightlessness can induce changes in lumen diameters of vessels in arteriolar networks in hindlimb muscles and whether these changes are reversible. Method. Changes in lumen diameters of the vessels in the arteriolar network in soleus muscle of 4 wk tail-suspended (SUS-4), 1 wk (REC-1) and 5 wk (REC-5) recovered rats were examined and compared with that of control (CON) rats by use of the method of intra-arterial infusion of a carbon suspension. Result. The lumen diameters of the feeding arteries and arcade arterioles, and the transverse arterioles of the order of both V and II in the SUS-4 group were reduced by 31%, 29%, 28%, and 41%, respectively, as compared with that of the CON group (P<0.01). The diameters of these arterioles in REC-1 group were partially restored but remained significantly less than that of the CON group (P<0.05, or P<0.01). In REC-5 group, except for the transverse arterioles of order II, the diameters of all the other arterioles were fully recovered. Conclusion. These findings indicate that a 4 wk simulated weightlessness might induce atrophic changes in the arterioles of the hindlimb muscles. It also suggests that structural changes in arteriolar network might be an important mechanism accounting for postflight orthostatic intolerance.