Boudet C, Peyrin L
Arch Int Pharmacodyn Ther. 1986 Oct;283(2):312-20.
The ability of diosmin to inhibit venous catechol-O-methyltransferase (COMT) activity was studied comparing it with tropolone in rat superior mesenteric vein (MV), inferior vena cava (IVC) and saphenous vein (SV). Diosmin inhibited COMT activity in the mesenteric vein after 200 and 400 mg/kg i.p., but only at 400 mg/kg in IVC. The COMT inhibitory effect of diosmin (400 mg/kg) was smaller than that of tropolone (50 mg/kg). Furthermore, diosmin, but not tropolone, increased urinary normetanephrine (NMN) excretion (+56%) at 400 mg/kg and that of 3-methoxy 4-hydroxyphenylglycol (MHPG) in a dose-dependent way, thus suggesting that diosmin may exert an activating effect on sympathetic activity. Both mechanism--local inhibition of COMT and enhanced sympathetic activity--may contribute to increase NE levels in the synaptic clefts of the vascular wall and explain the venoconstrictor effect of this drug.
将地奥司明与托酚酮进行比较，研究了地奥司明抑制大鼠肠系膜上静脉（MV）、下腔静脉（IVC）和隐静脉（SV）中静脉儿茶酚-O-甲基转移酶（COMT）活性的能力。腹腔注射200和400mg/kg地奥司明后，其可抑制肠系膜静脉中的COMT活性，但仅在400mg/kg剂量下可抑制下腔静脉中的COMT活性。地奥司明（400mg/kg）对COMT的抑制作用小于托酚酮（50mg/kg）。此外，地奥司明（而非托酚酮）在400mg/kg剂量下可增加尿去甲变肾上腺素（NMN）排泄（增加56%），并以剂量依赖方式增加3-甲氧基-4-羟基苯乙二醇（MHPG）的排泄，因此提示地奥司明可能对交感神经活性具有激活作用。局部抑制COMT和增强交感神经活性这两种机制都可能有助于增加血管壁突触间隙中的去甲肾上腺素（NE）水平，并解释该药物的静脉收缩作用。
