某些四氢异喹啉类生物碱对大鼠脑内多巴胺和5-羟色胺受体的作用

本文报道十二种四氢异喹啉类生物碱对大鼠脑内D-2,5-HT₁和5-HT₂受体的结合特性。其中l-千金藤碱(l-STP)对这三种受体均有较高的亲和力,其Ki值分别为1.7×10^-7,9.4×10^-8和1.8×10^-7mol。l-莲碱(l-REM)对5-HT₂受体的亲和力与Z-STP相似(Ki=1.7×10^-7mol)。THB,THC和THJ对D-2受体的亲和力介于l-SPD和l-THP之间。本文报道的多数生物碱能同时影响两种或两种以上受体部位的结合特性,提示它们对单胺神经系统可能有复杂的相互作用。

THE ACTIONS OF SOME TETRAHYDROISOQUINOLINE ALKALOIDS ON DOPAMINE AND SEROTONIN RECEPTORS IN RAT BRAIN

Investigation of some tetrahydroisoquinoline alkaloids on their in vitro affinities to D-2,5-HT₁ and 5-HT₂ receptors in rat brain was made using radioreceptor binding assay. It was found that about 12 alkaloids of two different types (i. e. aporphines and protoberberines)influenced the binding properties of these three receptor sites to various extent. l-Stephanine (l-STP) exhibited relatively high affinity to D-2,5-HT₁ and 5-HT₂ receptors (K_i=1.7×10^-7mol, 9.4×10^-8mol and 1.8×10^-7 mol, respectively). The effect of l-roemerine (l-REM) on 5-HT₂ receptor appeared to be similar to that of l-STP, its K_i value was found to be 1.7×10^-7mol. The potencies of dl-tetrahydroberberine, dl-tetrahydrocoptisine and dl-tetrahydrojatrorrhizine on D-2 receptor are between those of l-stepholidine and l-tetrahydropalmatine. The majority of the alkaloids reported in this paper have been shown to bind to more than one receptor sites with varying affinities, indicating that they may possess complex interactions with monoamines and their transmission.