Chakravarty B J, Gillies A H, Carney S L
Clin Exp Pharmacol Physiol. 1985 May-Jun;12(3):235-8. doi: 10.1111/j.1440-1681.1985.tb02638.x.
The nature of calcium dependence of natriuretic fraction (NF)-induced contractions in the rat smooth muscle anococcygeus and a possible correlation between the effect of NF on sodium transport and its natriuretic potency was investigated. NF and noradrenaline-induced contractions were partially dependent on external calcium concentration. Ouabain and potassium (K) free solution (KoPSS)-induced contractions were totally dependent on external calcium and were more effectively inhibited by calcium antagonists than those of NF and noradrenaline suggesting pharmacomechanical coupling as the mode of calcium dependence of NF. Like other agonists which contract by pharmacomechanical coupling, NF stimulated sodium transport (86rubidium uptake) in dog saphenous vein. Such stimulation correlated positively (r = 0.495, n = 17, P less than 0.05) with the natriuretic potency of NF. NF, like noradrenaline, contracts smooth muscle by pharmacomechanical coupling and NF-induced natriuresis is associated with stimulation of the sodium pump.
研究了利钠分数（NF）诱导的大鼠肛门尾骨肌平滑肌收缩的钙依赖性本质，以及NF对钠转运的影响与其利钠效力之间的可能相关性。NF和去甲肾上腺素诱导的收缩部分依赖于细胞外钙浓度。哇巴因和无钾溶液（KoPSS）诱导的收缩完全依赖于细胞外钙，并且钙拮抗剂对其抑制作用比对NF和去甲肾上腺素诱导的收缩更有效，提示药物-机械偶联是NF钙依赖性的方式。与其他通过药物-机械偶联收缩的激动剂一样，NF刺激犬隐静脉中的钠转运（86铷摄取）。这种刺激与NF的利钠效力呈正相关（r = 0.495，n = 17，P < 0.05）。NF与去甲肾上腺素一样，通过药物-机械偶联使平滑肌收缩，并且NF诱导的利钠作用与钠泵的刺激有关。
