Cuche J L, Marchand G R, Greger R F, Lang R C, Knox F G
J Clin Invest. 1976 Jul;58(1):71-6. doi: 10.1172/JCI108461.
A possible role for dopamine in phosphate handling by the dog kidney was investigated by intrarenal artery infusions of dopamine. Dopamine increased fractional phosphate excretion both in the presence and absence of control of parathyroid hormone and calcitonin. In addition, dopamine increased both renal blood flow and sodium excretion, however, the phosphaturia was independent of these changes; since 30 min after completion of dopamine infusion, renal blood flow and sodium excretion returned to control levels and phosphate excretion remained elevated. For comparison, the vasodilator isoproterenol increased renal blood flow and sodium excretion without a significant change in fractional phosphate excretion. Thus, the phosphaturic effect of dopamine is probably independent of its vasodilator effect. The phosphaturic effect of dopamine could not be accounted for by subsequent conversion to norepinephrine, since norepinephrine was antiphosphaturic in the dog. The effect of endogenous dopamine on renal phosphate excretion was investigated by intrarenal infusion of the precursor dopa. Dopa was phosphaturic both in the presence and absence of parathyroid hormone and calcitonin. In dogs pretreated with carbidopa, which blocks conversion of dopa to dopamine, dopa was no longer phosphaturic, although the kidney remained responsive to dopamine. It is postulated that dopamine may play a role in the intrarenal regulation of phosphate excretion.
通过肾内动脉输注多巴胺，研究了多巴胺在犬肾处理磷酸盐过程中可能发挥的作用。无论有无甲状旁腺激素和降钙素的调控，多巴胺均可增加磷酸盐排泄分数。此外，多巴胺可增加肾血流量和钠排泄量，然而，磷酸盐尿症与这些变化无关；因为在多巴胺输注结束30分钟后，肾血流量和钠排泄量恢复到对照水平，而磷酸盐排泄量仍保持升高。作为对照，血管扩张剂异丙肾上腺素增加了肾血流量和钠排泄量，但磷酸盐排泄分数无显著变化。因此，多巴胺的磷酸盐尿症作用可能与其血管扩张作用无关。多巴胺的磷酸盐尿症作用不能用随后转化为去甲肾上腺素来解释，因为在犬中去甲肾上腺素具有抗磷酸盐尿症作用。通过肾内输注多巴胺前体多巴，研究了内源性多巴胺对肾磷酸盐排泄的影响。无论有无甲状旁腺激素和降钙素，多巴均具有磷酸盐尿症作用。在用卡比多巴预处理的犬中，卡比多巴可阻止多巴转化为多巴胺，尽管肾脏对多巴胺仍有反应，但多巴不再具有磷酸盐尿症作用。据推测，多巴胺可能在肾内磷酸盐排泄调节中发挥作用。
