Sex and ageing differences in resting arterial pressure regulation: the role of the β-adrenergic receptors
Sex and ageing differences in resting arterial pressure regulation: the role of the β-adrenergic receptors
复制标题
DOI：
10.1113/jphysiol.2011.212753
复制
发表时间：
2011-11-01
影响因子：
5.5
通讯作者：
Joyner, Michael J.
中科院分区：
文献类型：
--
作者：
Hart, Emma C.;Charkoudian, Nisha;Joyner, Michael J.
在男性中，肌肉交感神经活动（MSNA）与总外周阻力（TPR）呈正相关，与心输出量（CO）呈负相关。然而，在年轻女性中没有观察到这种关系。我们的目的是调查是否同时β-肾上腺素能刺激抵消这种平衡的年轻女性。此外，我们的目的是检查是否有能力的β-肾上腺素能受体抵消转导MSNA到血管收缩张力在绝经后妇女丢失。我们测量了17名年轻男性、17名年轻女性和15名绝经后（PM）女性在普萘洛尔全身性β受体阻滞前后的MSNA（腓神经微神经造影）、动脉压（肱动脉线）、CO（Modelflow）、TPR和前臂血管传导性（FVC）对去甲肾上腺素剂量增加（NA; 2、4和8 ng（100 ml）（-1）min（-1））的变化。在年轻女性中，最后两次NA剂量的FVC百分比和绝对变化在β受体阻滞期间更大（P < 0.05），而年轻男性和PM女性中，FVC在β受体阻滞之前和期间的变化相似（P > 0.05）。在β受体阻滞剂之前，年轻女性的MSNA与TPR或平均动脉压（MAP）无关。β受体阻断后MSNA与TPR（r = 0.59，P < 0.05）和MAP（r = 0.58，P < 0.05）呈正相关。在PM女性和年轻男性中，MSNA与TPR呈正相关。β-封锁对这种关系没有影响。我们的数据表明，β-肾上腺素能受体抵消α-肾上腺素能血管收缩的年轻女性，而不是年轻男性或PM女性。这些发现可以部分解释女性绝经后血压升高的趋势。
In men, muscle sympathetic nerve activity (MSNA) is positively related to total peripheral resistance (TPR) and inversely related to cardiac output (CO). However, this relationship was not observed in young women. We aimed to investigate whether simultaneous beta-adrenergic stimulation offsets this balance in young women. Furthermore, we aimed to examine whether the ability of the beta-adrenergic receptors to offset the transduction of MSNA into vasoconstrictor tone was lost in postmenopausal women. We measured MSNA (peroneal microneurography), arterial pressure (brachial line), CO (Modelflow), TPR and changes in forearm vascular conductance (FVC) to increasing doses of noradrenaline (NA; 2, 4 and 8 ng (100 ml)(-1) min(-1)) before and after systemic beta-blockade with propranolol in 17 young men, 17 young women and 15 postmenopausal (PM) women. The percentage and absolute change in FVC to the last two doses of NA were greater during beta-blockade in young women (P < 0.05), whereas the change in FVC was similar before and during beta-blockade in young men and PM women (P > 0.05). Before beta-blockade there was no relationship of MSNA to TPR or mean arterial pressure (MAP) in young women. Following beta-blockade, MSNA became positively related to TPR (r = 0.59, P < 0.05) and MAP (r = 0.58, P < 0.05). In the PM women and young men, MSNA was positively associated with TPR. beta-Blockade had no effect on this relationship. Our data suggest that the beta-adrenergic receptors offset alpha-adrenergic vasoconstriction in young women but not young men or PM women. These findings may explain in part the tendency for blood pressure to rise after menopause in women.