Bertaccini G, Molina E, Zappia L, Zseli J
Naunyn Schmiedebergs Arch Pharmacol. 1979 Oct;309(1):65-8. doi: 10.1007/BF00498757.
Histamine and some related compounds acting selectively on H2-or H1 receptors were tested for their ability to contract the guinea pig ileum, in the usual whole ileum preparation and in the longitudinal muscle preparation. The concentrations elicited by histamine in both kinds of preparations were not potentiated by cimetidine or metiamide and were not inhibited by administration of H2 receptor selective agonists in doses which were subthreshold for contracting the guinea pig ileum; higher doses of the H2 agonists could actually potentiate the effect of histamine. The results obtained suggest that H2 receptors with relaxing effect do not occur in the guinea pig ileum or at least that they are not involved in the contraction of the longitudinal muscle layers. The possibility that a sub-type of H2 receptors with properties different from those of the "classical" H2 receptors so far known, exists in the guinea pig ileum, cannot be excluded.
在常规的全肠段制备和纵肌制备中，对组胺及一些选择性作用于H2或H1受体的相关化合物收缩豚鼠回肠的能力进行了测试。西咪替丁或甲硫米特不会增强组胺在两种制剂中引发的浓度，给予低于收缩豚鼠回肠阈值剂量的H2受体选择性激动剂也不会抑制该浓度；更高剂量的H2激动剂实际上可增强组胺的作用。所得结果表明，具有舒张作用的H2受体在豚鼠回肠中不存在，或者至少它们不参与纵肌层的收缩。不能排除豚鼠回肠中存在一种性质不同于目前已知“经典”H2受体的H2受体亚型的可能性。
