Junien J L, Guillaume M, Lakatos C, Sterne J
Arch Int Pharmacodyn Ther. 1981 Aug;252(2):313-26.
LA 2851, 2-4-diamino-7-methyl-pyrazolo (1,5a) 1, 3, 5 triazine has been found to possess potent bronchodilator and inhibitor properties on experimental active and passive anaphylaxis. In vitro evaluation on guinea-pig trachea indicated that LA 2851 had relaxant properties on unstimulated and stimulated (histamine or pilocarpine) strips. Resistance and compliance measurement in anaesthetized dogs and guinea-pigs showed that the drug reversed or prevented in vivo bronchoconstriction due to histamine. The relaxant effect was not linked to beta stimulating property. LA 2851 was as active as theophylline in all tests used. LA 2851 and theophylline prevented anaphylactic shock in mice. DSCG was poorly active. IgE mediated passive cutaneous anaphylaxis in rat was dose-dependently inhibited by LA 2851 (DSCG greater than LA 2851 greater than theophylline). According to these results the compound decreased histamine release from rat mast cells induced by different secretagogues (LA 2851 greater than DSCG greater than theophylline). No tachyphylaxis (PCA) nor time preincubation dependency (mast cells) was found with LA 2851 as it has been reported for DSCG. LA 2851 by its pharmacological properties associated with a very low toxicity (2.5 to 5 times less than theophylline) provides a new potential agent for respiratory diseases.
LA 2851，即2,4 - 二氨基 - 7 - 甲基 - 吡唑并(1,5a)1,3,5 - 三嗪，已被发现对实验性主动和被动过敏反应具有强效支气管扩张和抑制特性。对豚鼠气管的体外评估表明，LA 2851对未受刺激和受刺激（组胺或毛果芸香碱）的气管条具有松弛特性。在麻醉犬和豚鼠身上进行的阻力和顺应性测量显示，该药物可逆转或预防组胺引起的体内支气管收缩。这种松弛作用与β刺激特性无关。在所有使用的测试中，LA 2851与茶碱的活性相当。LA 2851和茶碱可预防小鼠的过敏性休克。色甘酸钠活性较差。LA 2851剂量依赖性地抑制大鼠体内IgE介导的被动皮肤过敏反应（色甘酸钠＞LA 2851＞茶碱）。根据这些结果，该化合物可减少不同促分泌剂诱导的大鼠肥大细胞组胺释放（LA 2851＞色甘酸钠＞茶碱）。与色甘酸钠不同，LA 2851未发现快速耐受性（PCA）和时间预孵育依赖性（肥大细胞）。LA 2851因其药理特性以及极低的毒性（比茶碱低2.5至5倍），为呼吸系统疾病提供了一种新的潜在药物。
