Müller-Schweinitzer E
Int J Clin Pharmacol Ther Toxicol. 1984 Dec;22(12):677-82.
The vasoconstrictor activity of dihydroergotamine is long-lasting and independent from continuously elevated plasma levels. There is evidence that dihydroergotamine accumulates at the vascular smooth muscle cells and elicits venoconstriction through both stimulation of 5-HT receptors as well as sensitization of the venous smooth muscle to the constrictor activity of biogenic amines. In vivo, the vasoconstrictor activity of dihydroergotamine is probably modulated through vasoactive metabolites, i.e., the vasoconstrictor profile and efficacy obviously varies with the ratio of the parent drug and dihydroergotamine metabolites in plasma.
双氢麦角胺的血管收缩活性持久，且与持续升高的血浆水平无关。有证据表明，双氢麦角胺在血管平滑肌细胞中蓄积，并通过刺激5-羟色胺受体以及使静脉平滑肌对生物胺的收缩活性敏感化来引发静脉收缩。在体内，双氢麦角胺的血管收缩活性可能通过血管活性代谢产物进行调节，即血管收缩特征和效力显然会随血浆中母体药物与双氢麦角胺代谢产物的比例而变化。
