Houben A J, Krekels M M, Schaper N C, Fuss-Lejeune M J, Rodriguez S A, de Leeuw P W
Department of Internal Medicine, University Hospital Maastricht, The Netherlands.
Cardiovasc Res. 1998 Aug;39(2):442-50. doi: 10.1016/s0008-6363(98)00072-8.
Infusion of ANP in anephric dogs causes a decrease in cardiac output and a rise in peripheral vascular resistance. This reduced cardiac output is possibly related to increased resistance to venous return generated in the microcirculation by venular constriction. The aim of the present study was to evaluate in healthy volunteers the effects of low-dose ANP infusion on both conjunctival and skin microcirculation during high or low salt diet.
ANP (7.5 ng/kg/min) and placebo were infused (i.v.) for 4 h, in random order on two separate days, in two groups of 10 healthy male volunteers each. One group was studied during high salt (ad libitum), and one group during low salt (55 mmol Na+/24 h) diet. Microvascular density and diameters of both conjunctiva and nailfold were studied using intravital videomicroscopy. Nailfold capillary red blood cell velocity (CBV) was studied using intravital videomicroscopy, and skin (thermoregulatory) blood flow (SBF) was studied using laser-Doppler fluximetry.
In the high salt group ANP induced a 43% reduction in basal SBF as compared to an 18% reduction by placebo (P < 0.01). Parallel to SBF, ANP significantly reduced CBV (P < 0.02). Conjunctival capillary density decreased by 5% during ANP, while it increased by 28% during placebo (P < 0.05). No such effects of ANP were observed in the low salt group. Blood pressure and heart rate were not influenced by ANP infusion in neither group.
Infusion of low doses of ANP into humans on an ad libitum salt diet results in vasoconstriction of the microcirculation, probably on the venular side. The lack of effect of ANP on the microcirculation during low salt diet may be related to a higher vascular tone prior to infusion.
给无肾犬输注心钠素（ANP）会导致心输出量降低和外周血管阻力升高。这种心输出量降低可能与小静脉收缩在微循环中产生的静脉回流阻力增加有关。本研究的目的是评估在高盐或低盐饮食期间，低剂量ANP输注对健康志愿者结膜和皮肤微循环的影响。
两组各10名健康男性志愿者，在两天内随机顺序静脉输注ANP（7.5 ng/kg/分钟）和安慰剂，每次输注4小时。一组在高盐（随意饮食）期间进行研究，另一组在低盐（55 mmol钠/24小时）饮食期间进行研究。使用活体视频显微镜研究结膜和甲襞的微血管密度和直径。使用活体视频显微镜研究甲襞毛细血管红细胞速度（CBV），并使用激光多普勒血流仪研究皮肤（体温调节）血流量（SBF）。
在高盐组中，与安慰剂使SBF降低18%相比，ANP使基础SBF降低了43%（P < 0.01）。与SBF平行，ANP显著降低了CBV（P < 0.02）。ANP输注期间结膜毛细血管密度降低了5%，而安慰剂输注期间增加了28%（P < 0.05）。在低盐组中未观察到ANP的此类作用。两组中ANP输注均未影响血压和心率。
给随意摄入盐的人群输注低剂量ANP会导致微循环血管收缩，可能是在小静脉侧。低盐饮食期间ANP对微循环缺乏作用可能与输注前较高的血管张力有关。
