Sham J S, Pang P K
Gen Comp Endocrinol. 1986 Nov;64(2):250-3. doi: 10.1016/0016-6480(86)90010-9.
The involvement of extracellular calcium in the chronotropic action of parathyroid hormone (PTH) in isolated quail atria was studied. Bovine (b) PTH-(1-34) caused dose-dependent increases in the atrial beating rate. The PTH-induced positive chronotropism was significantly attenuated by lowering the extracellular calcium concentration or by using the calcium channel antagonists verapamil and D600. This suggests the importance of calcium influx in the cardiac action of PTH. beta-Adrenergic blockade with propranolol did not affect the responses to bPTH-(1-34). This further substantiates the previous findings that the PTH action is independent of cardiac beta-adrenoceptor stimulation.
研究了细胞外钙在甲状旁腺激素(PTH)对离体鹌鹑心房变时作用中的参与情况。牛(b)PTH-(1-34)引起心房跳动频率呈剂量依赖性增加。通过降低细胞外钙浓度或使用钙通道拮抗剂维拉帕米和D600,PTH诱导的正性变时作用显著减弱。这表明钙内流在PTH的心脏作用中具有重要性。用普萘洛尔进行β-肾上腺素能阻断并不影响对bPTH-(1-34)的反应。这进一步证实了先前的研究结果,即PTH的作用独立于心脏β-肾上腺素能受体刺激。