Belcheva A, Zhelyazkova M
Department of Pharmacology, Higher Medical Institute, Varna.
Acta Physiol Pharmacol Bulg. 1988;14(4):49-54.
The influence of the H1- and H2-histaminergic blockers promethazine and cimetidine, respectively, as well as of a combination of both drugs on the histamine release from rat ear skin, induced by compound 48/80, was studied. Cimetidine did not interfere with the effects of comp. 48/80, while promethazine increased almost three times the histamine-releasing effects of comp. 48/80. This effect of promethazine was reduced when the latter was combined with cimetidine. Cimetidine and promethazine did not produce any per se effect on the histamine content of the ear skin tissue. The two histaminergic blockers antagonized the vasodilation induced by exogenous histamine injected intradermally, the combination of the drugs in the higher dose used being most efficient. The effect of the combination was more pronounced as compared to that of promethazine when applied alone in the corresponding dose (25 mg/kg) and was almost equal to the effect of cimetidine administered alone in a dose of 200 mg/kg. The results suggest an important role for H2-histaminergic receptors in the skin vessels of rat as well as in the prevention of the mast cell degranulation at least in cases when it is induced by comp. 48/80.
分别研究了H1和H2组胺能阻滞剂异丙嗪和西咪替丁，以及两种药物联合使用对化合物48/80诱导的大鼠耳皮肤组胺释放的影响。西咪替丁不干扰化合物48/80的作用，而异丙嗪使化合物48/80的组胺释放作用增加了近三倍。当异丙嗪与西咪替丁联合使用时，其这种作用减弱。西咪替丁和异丙嗪本身对耳皮肤组织的组胺含量没有任何影响。这两种组胺能阻滞剂拮抗皮内注射外源性组胺引起的血管舒张，所用较高剂量的药物联合使用时效果最佳。与单独应用相应剂量（25mg/kg）的异丙嗪相比，联合用药的效果更明显，且几乎等同于单独给予200mg/kg西咪替丁的效果。结果表明，H2组胺能受体在大鼠皮肤血管中以及至少在由化合物48/80诱导的肥大细胞脱颗粒的预防中起重要作用。
