UNASSIGNED: Eighty-six Caucasian men were studied. Water load test consisted in oral administration of 15-20 ml of water/kg body weight over 40-45 min. BP, heart rate, serum copeptin, urine hyaluronidase activity and AQP2 were monitored for 4 hours.
UNASSIGNED: In response to water drinking, BP raised in all groups with a peak at 20-40 min. Baseline levels of serum copeptin, urinary hyaluronidase activity and AQP2/creatinine ratio were similar among groups and all decreased after water load, reaching their nadir at 120 min and then gradually recovering to baseline values. Significantly, a blunted reduction in serum copeptin, urinary hyaluronidase activity and AQP2/creatinine ratio was observed in NT+ compared to NT- subjects. A strong positive correlation was also found between urinary hyaluronidase activity and AQP2/creatinine ratio, and, although limited to the NT- group, both parameters were positively associated with systolic BP.
UNASSIGNED: Our results demonstrate for the first time the existence in men of a close association between urinary hyaluronidase activity and vasopressinergic system and suggest that NT+ subjects have a reduced ability to respond to water loading possibly contributing to the blood volume expansion involved in early-stage hypertension. Considering these data, AVP could play a central role in BP regulation by affecting water metabolism through both hyaluronidase activity and AQP2 channel expression.
■研究了86名白人男性。水负荷试验包括在40-45分钟内口服15-20ml水/kg体重。BP,心率,血清和肽素,监测尿透明质酸酶活性和AQP24小时.
■为了应对饮用水,所有组的BP均在20-40分钟达到峰值。血清和肽素的基线水平,尿透明质酸酶活性和AQP2/肌酐比值在各组之间相似,并且在水负荷后均下降,在120分钟达到最低点,然后逐渐恢复到基线值。重要的是,血清和肽素的减少,与NT-受试者相比,在NT+受试者中观察到尿透明质酸酶活性和AQP2/肌酐比值.尿透明质酸酶活性与AQP2/肌酐比值之间也有很强的正相关,and,虽然仅限于NT-组,这两个参数均与收缩压呈正相关.
■我们的结果首次证明了男性尿透明质酸酶活性与血管加压素能系统之间存在密切联系,并表明NT受试者对水负荷的反应能力降低可能导致早期高血压患者的血容量膨胀。考虑到这些数据,AVP可以通过透明质酸酶活性和AQP2通道表达影响水代谢,在BP调节中发挥核心作用。