Aadland E, Berstad A, Semb L S
Scand J Gastroenterol. 1977;12(4):501-6. doi: 10.3109/00365527709181695.
Two series of experiments were carried out in three healthy volunteers. In one series increasing doses of cimetidine were tested on a constant background stimulation with 0.15 microgram-kg-1h-1 of pentagastrin. In the other series of experiments increasing doses of pentagastrin were given either alone or in combination with a fixed dose of cimetidine (1.2 mg-kg-1h-1). Pentagastrin and cimetidine were given as continuous intravenous infusions, the various doses tested on separate days. The inhibition of acid output in response to pentagastrin stimulation increased almost linearly with the log dose of cimetidine. Fifty per cent inhibition of the response to 0.15 microgram-kg-1h-1 of pentagastrin was achieved by about 0.6 mg-kg-1h-1 of cimetidine. 2.4 mg-kg-1h-1 of cimetidine gave on average 90% inhibition. The inhibition caused by cimetidine decreased to a minimum of 57% and could not be overcome by increasing the doses of pentagastrin. The results suggest a mixture of competitive and noncompetitive interaction. The effect of cimetidine on pepsin secretion was less regular. Generally, pepsin output was less inhibited than acid output.
在三名健康志愿者身上进行了两组实验。在一组实验中，在以0.15微克·千克⁻¹·小时⁻¹的五肽胃泌素进行持续背景刺激的情况下，测试了递增剂量的西咪替丁。在另一组实验中，单独给予递增剂量的五肽胃泌素，或者与固定剂量的西咪替丁（1.2毫克·千克⁻¹·小时⁻¹）联合给予。五肽胃泌素和西咪替丁均通过持续静脉输注给药，不同剂量在不同日期进行测试。对五肽胃泌素刺激的胃酸分泌抑制几乎随西咪替丁的对数剂量呈线性增加。约0.6毫克·千克⁻¹·小时⁻¹的西咪替丁可实现对0.15微克·千克⁻¹·小时⁻¹五肽胃泌素反应的50%抑制。2.4毫克·千克⁻¹·小时⁻¹的西咪替丁平均产生90%的抑制作用。西咪替丁引起的抑制作用降至最低57%，且不能通过增加五肽胃泌素的剂量来克服。结果提示存在竞争性和非竞争性相互作用的混合情况。西咪替丁对胃蛋白酶分泌的影响不太规律。一般来说，胃蛋白酶分泌受到的抑制比胃酸分泌受到的抑制要小。
