Vacca G, Battaglia A, Ferro R, Grossini E, Mary D A, Molinari C, Surico N
Dipartimento di Scienze Mediche, Facoltà di Medicina e Chirurgia, Università di Torino, Novara, Italy.
J Auton Nerv Syst. 1998 Nov 10;73(2-3):163-9. doi: 10.1016/s0165-1838(98)00136-2.
It has recently been shown that distension of the uterus in anaesthetized pigs causes reflex haemodynamic responses through efferent sympathetic mechanisms. The present study was undertaken to determine whether these mechanisms include activation of the renin-angiotensin system. The same methods were used in 14 pigs which were anaesthetized with alpha-chloralose and artificially ventilated. Balloons positioned within the uterus were distended for periods of 30 min by injecting 20 ml of warm Ringer solution. The responses of arterial blood pressure and heart rate were respectively prevented by blockade of alpha-adrenergic receptors with phentolamine and atrial pacing. Changes in plasma renin activity (PRA) were assessed during the last minute of distension by radioimmunoassay of angiotensin I. In each of 10 pigs, distension of the uterus (mean uterine transmural pressure of 17 mmHg) caused an increase in PRA in the absence of changes of interfering haemodynamic variables. In the remaining four pigs, this response was graded by step increments of the distension. The increase in PRA caused by uterine distension was abolished by bilateral section of the renal nerves (five pigs) or by blockade of beta-adrenergic receptors with propranolol. The present study showed that distension of the uterus in anaesthetized pigs primarily caused a reflex increase in PRA. This reflex response was mediated by renal nerves and involved beta-adrenergic receptors.
最近研究表明，麻醉猪的子宫扩张可通过传出交感神经机制引起反射性血流动力学反应。本研究旨在确定这些机制是否包括肾素-血管紧张素系统的激活。对14只用α-氯醛糖麻醉并进行人工通气的猪采用相同方法。通过注入20 ml温林格溶液使置于子宫内的球囊扩张30分钟。用酚妥拉明阻断α-肾上腺素能受体和心房起搏分别可防止动脉血压和心率的反应。在扩张的最后一分钟，通过放射免疫法测定血管紧张素I来评估血浆肾素活性（PRA）的变化。在10只猪中，每只猪子宫扩张（平均子宫跨壁压为17 mmHg）在未干扰血流动力学变量变化的情况下导致PRA升高。在其余4只猪中，通过逐步增加扩张程度来分级这种反应。子宫扩张引起的PRA升高可通过双侧切断肾神经（5只猪）或用普萘洛尔阻断β-肾上腺素能受体来消除。本研究表明，麻醉猪的子宫扩张主要引起PRA反射性升高。这种反射反应由肾神经介导并涉及β-肾上腺素能受体。
